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Schedule III - Real Estate and Accumulated Depreciation (Details) (USD $) | 12 Months Ended |
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Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | $ 251,150,000us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,575,297,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 2,152,990,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (283,611,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,416,905,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 2,027,771,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements |  |  |  |
Properties Pledged as Collateral Book Value | 381,600,000star_PropertiesPledgedAsCollateralBookValue |  |  |  |
Aggregate Cost for Federal Income Tax Purposes | 3,780,000,000star_AggregateCostForFederalIncomeTaxPurposes |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (481,980,000)us-gaap_RealEstateAccumulatedDepreciation | [2] | (432,374,000)us-gaap_RealEstateAccumulatedDepreciation | (388,346,000)us-gaap_RealEstateAccumulatedDepreciation | (356,810,000)us-gaap_RealEstateAccumulatedDepreciation
SEC Schedule III, Real Estate, Gross | 3,444,676,000us-gaap_RealEstateGrossAtCarryingValue | [2],[3] | 3,589,072,000us-gaap_RealEstateGrossAtCarryingValue | 3,763,310,000us-gaap_RealEstateGrossAtCarryingValue | 3,927,750,000us-gaap_RealEstateGrossAtCarryingValue
Real Estate Improvements and Additions | 145,238,000star_RealEstateImprovementsAndAdditions |  | 126,664,000star_RealEstateImprovementsAndAdditions | 111,760,000star_RealEstateImprovementsAndAdditions |
SEC Schedule III, Real Estate, Acquisitions Through Foreclosures | 77,867,000us-gaap_RealEstateAcquisitionsThroughForeclosures |  | 31,764,000us-gaap_RealEstateAcquisitionsThroughForeclosures | 269,100,000us-gaap_RealEstateAcquisitionsThroughForeclosures |
SEC Schedule III, Real Estate, Other Acquisitions | 4,666,000us-gaap_RealEstateOtherAcquisitions |  | 69,379,000us-gaap_RealEstateOtherAcquisitions | 0us-gaap_RealEstateOtherAcquisitions |
SEC Schedule III, Real Estate, Cost of Real Estate Sold | (341,453,000)us-gaap_RealEstateCostOfRealEstateSold |  | (388,906,000)us-gaap_RealEstateCostOfRealEstateSold | (510,504,000)us-gaap_RealEstateCostOfRealEstateSold |
Impairment of Real Estate | (30,714,000)us-gaap_SECScheduleIIIRealEstateWritedownOrReserveAmount |  | (13,139,000)us-gaap_SECScheduleIIIRealEstateWritedownOrReserveAmount | (34,796,000)us-gaap_SECScheduleIIIRealEstateWritedownOrReserveAmount |
SEC Schedule III, Real Estate Accumulated Depreciation, Depreciation Expense | (62,299,000)us-gaap_SECScheduleIIIRealEstateAccumulatedDepreciationDepreciationExpense |  | (59,208,000)us-gaap_SECScheduleIIIRealEstateAccumulatedDepreciationDepreciationExpense | (59,968,000)us-gaap_SECScheduleIIIRealEstateAccumulatedDepreciationDepreciationExpense |
SEC Schedule III, Real Estate Accumulated Depreciation, Real Estate Sold | 12,693,000us-gaap_RealEstateAccumulatedDepreciationRealEstateSold |  | 15,180,000us-gaap_RealEstateAccumulatedDepreciationRealEstateSold | 28,432,000us-gaap_RealEstateAccumulatedDepreciationRealEstateSold |
Real Estate Asses Held-for-Sale [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (13,100,000)us-gaap_RealEstateAccumulatedDepreciation / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_RealEstateAssesHeldforSaleMember |  |  |  |
Hotel [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 47,039,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 175,803,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 4,644,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 47,039,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 180,447,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (60,235,000)us-gaap_RealEstateAccumulatedDepreciation / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember |  |  |  |
SEC Schedule III, Real Estate, Gross | 227,486,000us-gaap_RealEstateGrossAtCarryingValue / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember |  |  |  |
Hotel [Member] | California HCA 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaHca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 4,394,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaHca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 27,030,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaHca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (871,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaHca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 4,394,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaHca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 26,159,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaHca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (11,311,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaHca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 30,553,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaHca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
Hotel [Member] | California HCA 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaHca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 3,308,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaHca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 20,623,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaHca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (664,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaHca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 3,308,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaHca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 19,959,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaHca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (8,614,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaHca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 23,267,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaHca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
Hotel [Member] | Colorado HCO 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoHco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,242,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoHco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 7,865,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoHco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (253,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoHco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,242,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoHco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 7,612,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoHco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (3,278,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoHco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 8,854,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoHco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
Hotel [Member] | Georgia HGA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaHga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 6,378,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaHga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 25,514,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaHga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 858,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaHga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 6,378,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaHga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 26,372,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaHga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (3,700,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaHga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 32,750,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaHga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember |  |  |  |
Hotel [Member] | Hawaii HHI 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiHhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 17,996,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiHhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 17,996,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiHhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 6,573,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiHhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 17,996,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiHhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 24,569,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiHhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (4,531,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiHhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 42,565,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiHhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
Hotel [Member] | Hawaii HHI 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiHhi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 3,000,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiHhi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 12,000,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiHhi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,090,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiHhi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 3,000,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiHhi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 13,090,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiHhi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (1,628,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiHhi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 16,090,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiHhi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember |  |  |  |
Hotel [Member] | Utah HUT 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahHut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 5,620,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahHut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 32,695,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahHut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,058,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahHut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 5,620,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahHut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 31,637,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahHut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (13,790,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahHut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 37,257,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahHut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
Hotel [Member] | Washington HWA 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonHwa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 5,101,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonHwa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 32,080,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonHwa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,031,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonHwa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 5,101,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonHwa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 31,049,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonHwa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (13,383,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonHwa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 36,150,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonHwa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_HotelMember | [4] |  |  |
Commercial Office Real Estate |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 109,881,000us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 61,597,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 593,276,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 35,978,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 62,604,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 628,247,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (185,440,000)us-gaap_RealEstateAccumulatedDepreciation / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate, Gross | 690,851,000us-gaap_RealEstateGrossAtCarryingValue / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
Commercial Office Real Estate | Arizona OAZ 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,033,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 6,652,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 951,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,033,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 7,603,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (2,825,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 8,636,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
Commercial Office Real Estate | Arizona OAZ 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,033,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 6,652,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 287,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,033,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 6,939,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (2,589,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 7,972,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
Commercial Office Real Estate | Arizona OAZ 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,033,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 6,652,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 205,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,033,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 6,857,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (2,570,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 7,890,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
Commercial Office Real Estate | Arizona OAZ 005 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 701,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 4,339,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 701,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 4,339,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (1,645,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 5,040,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
Commercial Office Real Estate | Arizona OAZ 006 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 10,780,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 36,336,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,294,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 10,780,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 37,630,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (5,827,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 48,410,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaOaz006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
Commercial Office Real Estate | California OCA 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaOca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 4,139,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaOca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 5,064,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaOca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,596,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaOca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 4,139,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaOca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 6,660,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaOca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (2,229,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaOca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 10,799,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaOca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
Commercial Office Real Estate | Colorado OCO 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoOco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,757,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoOco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 16,930,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoOco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 6,476,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoOco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,757,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoOco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 23,406,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoOco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (8,823,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoOco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 25,163,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoOco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
Commercial Office Real Estate | Colorado OCO 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 4,856,000us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoOco002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoOco002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 16,752,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoOco002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 48,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoOco002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoOco002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 16,800,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoOco002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (5,356,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoOco002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 16,800,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoOco002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
Commercial Office Real Estate | Florida OFL 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaOfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 2,517,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaOfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 14,484,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaOfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 5,112,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaOfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 2,517,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaOfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 19,596,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaOfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (2,168,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaOfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 22,113,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaOfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
Commercial Office Real Estate | Georgia OGA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaOga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 905,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaOga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 6,744,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaOga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 45,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaOga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 905,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaOga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 6,789,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaOga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (3,142,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaOga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 7,694,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaOga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
Commercial Office Real Estate | Georgia OGA 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaOga002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 5,709,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaOga002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 49,091,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaOga002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 22,344,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaOga002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 5,709,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaOga002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 71,435,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaOga002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (24,788,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaOga002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 77,144,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaOga002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
Commercial Office Real Estate | Massachusetts OMA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 12,581,000us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsOma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,600,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsOma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 21,947,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsOma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 285,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsOma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,600,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsOma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 22,232,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsOma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (7,126,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsOma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 23,832,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsOma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
Commercial Office Real Estate | Maryland OMD 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 12,033,000us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandOmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,800,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandOmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 18,706,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandOmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 740,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandOmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,800,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandOmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 19,446,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandOmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (6,044,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandOmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 21,246,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandOmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
Commercial Office Real Estate | Michigan OMI 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganOmi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 5,374,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganOmi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 137,956,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganOmi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 243,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganOmi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 5,374,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganOmi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 138,199,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganOmi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (25,622,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganOmi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 143,573,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganOmi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
Commercial Office Real Estate | New Jersey ONJ 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 52,675,000us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 7,726,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 74,429,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 10,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 7,724,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 74,441,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (22,447,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 82,165,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
Commercial Office Real Estate | New Jersey ONJ 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 11,517,000us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,008,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 13,763,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (81,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,008,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 13,682,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (3,725,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 14,690,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
Commercial Office Real Estate | New Jersey ONJ 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 16,219,000us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 2,456,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 28,955,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 767,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 2,456,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 29,722,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (7,967,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 32,178,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyOnj003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [4] |  |  |
Commercial Office Real Estate | Pennsylvania OPA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaOpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 690,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaOpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 26,098,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaOpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (49,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaOpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 690,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaOpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 26,049,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaOpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (8,656,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaOpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 26,739,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaOpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
Commercial Office Real Estate | Tennessee OTN 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TennesseeOtn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 2,702,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TennesseeOtn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 25,129,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TennesseeOtn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (17,064,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TennesseeOtn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 2,702,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TennesseeOtn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 8,065,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TennesseeOtn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (7,878,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TennesseeOtn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 10,767,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TennesseeOtn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
Commercial Office Real Estate | Texas OTX 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,364,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 10,628,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 5,644,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 2,373,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 15,263,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (5,589,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 17,636,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
Commercial Office Real Estate | Texas OTX 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,233,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 15,160,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 146,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,233,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 15,306,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (5,480,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 16,539,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
Commercial Office Real Estate | Texas OTX 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 2,932,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 31,235,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 12,644,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 2,932,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 43,879,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (15,945,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 46,811,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
Commercial Office Real Estate | Texas OTX 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,230,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 5,660,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 482,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,230,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 6,142,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (2,303,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 7,372,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasOtx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
Commercial Office Real Estate | Wisconsin OWI 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinOwi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,875,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinOwi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 13,914,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinOwi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (6,147,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinOwi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,875,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinOwi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 7,767,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinOwi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (4,696,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinOwi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 9,642,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinOwi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialOfficeRealEstateMember |  |  |  |
Commercial Industrial Research and Development Real Estate [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 141,269,000us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 112,221,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 340,325,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 75,408,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 111,148,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 416,806,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (105,966,000)us-gaap_RealEstateAccumulatedDepreciation / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate, Gross | 527,954,000us-gaap_RealEstateGrossAtCarryingValue / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
Commercial Industrial Research and Development Real Estate [Member] | Arizona IAZ 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaIaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 2,519,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaIaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 7,481,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaIaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,009,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaIaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 2,519,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaIaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 8,490,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaIaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (1,249,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaIaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 11,009,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaIaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
Commercial Industrial Research and Development Real Estate [Member] | Arizona IAZ 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaIaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 3,279,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaIaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 5,221,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaIaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,387,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaIaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 3,279,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaIaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 7,608,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaIaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (1,185,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaIaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 10,887,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaIaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
Commercial Industrial Research and Development Real Estate [Member] | California ICA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 17,736,000us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 11,635,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 19,515,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 5,943,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 11,635,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 25,458,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (4,496,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 37,093,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
Commercial Industrial Research and Development Real Estate [Member] | California ICA 005 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 654,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 4,591,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,044,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 654,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 6,635,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (2,697,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 7,289,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
Commercial Industrial Research and Development Real Estate [Member] | California ICA 006 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,086,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 7,964,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,876,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,086,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 10,840,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (4,560,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 11,926,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
Commercial Industrial Research and Development Real Estate [Member] | California ICA 007 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 4,880,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 12,367,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 3,550,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 4,880,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 15,917,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (5,656,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 20,797,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
Commercial Industrial Research and Development Real Estate [Member] | California ICA 008 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 6,857,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 8,378,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,643,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 6,856,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 10,022,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (3,326,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 16,878,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
Commercial Industrial Research and Development Real Estate [Member] | California ICA 012 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 3,044,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 3,716,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 3,643,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 3,044,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 7,359,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (2,266,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 10,403,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
Commercial Industrial Research and Development Real Estate [Member] | California ICA 013 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 2,633,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 3,219,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 290,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 2,633,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 3,509,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (1,240,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 6,142,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
Commercial Industrial Research and Development Real Estate [Member] | California ICA 014 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 4,600,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 5,627,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 4,039,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 4,600,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 9,666,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (2,434,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 14,266,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
Commercial Industrial Research and Development Real Estate [Member] | California ICA 015 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 5,617,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 6,877,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 5,501,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 5,619,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 12,376,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (6,618,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 17,995,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
Commercial Industrial Research and Development Real Estate [Member] | California ICA 016 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 27,456,000us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 15,708,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 27,987,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 7,619,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 15,708,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 35,606,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (14,473,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 51,314,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
Commercial Industrial Research and Development Real Estate [Member] | California ICA 017 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 808,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 8,306,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 588,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 808,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 8,894,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (3,241,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 9,702,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaIca017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
Commercial Industrial Research and Development Real Estate [Member] | Colorado ICO 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoIco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 832,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoIco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,379,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoIco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoIco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 832,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoIco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,379,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoIco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (289,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoIco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,211,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoIco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
Commercial Industrial Research and Development Real Estate [Member] | Florida IFL 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 15,365,000us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 3,510,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 20,846,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 8,279,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 3,510,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 29,125,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (4,795,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 32,635,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
Commercial Industrial Research and Development Real Estate [Member] | Florida IFL 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 3,048,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 8,676,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 3,048,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 8,676,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (3,290,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 11,724,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
Commercial Industrial Research and Development Real Estate [Member] | Florida IFL 005 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,612,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 4,586,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,408,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,241,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 3,549,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (784,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 4,790,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
Commercial Industrial Research and Development Real Estate [Member] | Florida IFL 006 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,476,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 4,198,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (4,497,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 450,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 727,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (521,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,177,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaIfl006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
Commercial Industrial Research and Development Real Estate [Member] | Georgia IGA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 13,373,000us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaIga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 2,791,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaIga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 24,637,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaIga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 349,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaIga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 2,791,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaIga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 24,986,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaIga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (4,488,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaIga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 27,777,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaIga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
Commercial Industrial Research and Development Real Estate [Member] | Indiana IIN 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IndianaIin001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 462,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IndianaIin001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 9,224,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IndianaIin001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IndianaIin001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 462,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IndianaIin001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 9,224,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IndianaIin001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (2,303,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IndianaIin001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 9,686,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IndianaIin001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
Commercial Industrial Research and Development Real Estate [Member] | Massachusetts IMA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 18,400,000us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsIma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 7,439,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsIma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 21,774,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsIma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 10,979,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsIma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 7,439,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsIma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 32,753,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsIma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (5,391,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsIma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 40,192,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsIma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
Commercial Industrial Research and Development Real Estate [Member] | Michigan IMI 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganImi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 598,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganImi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 9,814,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganImi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganImi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 598,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganImi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 9,815,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganImi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (2,476,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganImi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 10,413,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganImi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
Commercial Industrial Research and Development Real Estate [Member] | Minnesota IMN 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaImn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 403,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaImn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,147,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaImn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (344,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaImn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,206,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaImn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaImn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaImn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,206,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaImn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
Commercial Industrial Research and Development Real Estate [Member] | Minnesota IMN 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaImn002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 6,705,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaImn002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 17,690,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaImn002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaImn002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 6,225,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaImn002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 18,170,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaImn002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (4,502,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaImn002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 24,395,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaImn002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
Commercial Industrial Research and Development Real Estate [Member] | North Carolina INC 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaInc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 680,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaInc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 5,947,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaInc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaInc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 680,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaInc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 5,947,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaInc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (1,543,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaInc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 6,627,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaInc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
Commercial Industrial Research and Development Real Estate [Member] | New Jersey INJ 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 21,340,000us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyInj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 8,368,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyInj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 15,376,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyInj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 21,141,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyInj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 8,368,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyInj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 36,517,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyInj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (6,085,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyInj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 44,885,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyInj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
Commercial Industrial Research and Development Real Estate [Member] | New York INY 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkIny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,796,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkIny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 5,108,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkIny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 4,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkIny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,796,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkIny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 5,112,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkIny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (1,939,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkIny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 6,908,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkIny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
Commercial Industrial Research and Development Real Estate [Member] | Texas ITX 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 3,617,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 3,432,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 3,617,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 3,432,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (719,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 7,049,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
Commercial Industrial Research and Development Real Estate [Member] | Texas ITX 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 13,278,000us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,631,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 27,858,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (416,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,631,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 27,442,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (4,872,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 29,073,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
Commercial Industrial Research and Development Real Estate [Member] | Texas ITX 005 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,314,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 8,903,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 46,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,314,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 8,949,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (3,389,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 10,263,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasItx005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember |  |  |  |
Commercial Industrial Research and Development Real Estate [Member] | Virginia IVA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 14,321,000us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaIVA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 2,619,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaIVA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 28,481,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaIVA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 142,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaIVA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 2,619,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaIVA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 28,623,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaIVA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (5,139,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaIVA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 31,242,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaIVA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialIndustrialResearchAndDevelopmentRealEstateMember | [4] |  |  |
Land |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 920,503,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 16,303,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 36,044,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 921,062,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 51,788,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (8,431,000)us-gaap_RealEstateAccumulatedDepreciation / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate, Gross | 972,850,000us-gaap_RealEstateGrossAtCarryingValue / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | Arizona LAZ 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaLaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 96,700,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaLaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaLaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaLaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 96,700,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaLaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaLaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaLaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 96,700,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaLaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | Arizona LAZ 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaLAZ002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 13,170,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaLAZ002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 5,144,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaLAZ002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 64,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaLAZ002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 13,170,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaLAZ002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 5,208,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaLAZ002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (472,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaLAZ002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 18,378,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaLAZ002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [4] |  |  |
Land | Florida LFA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 7,600,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 7,600,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 7,600,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | Florida LFA 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 8,100,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 8,100,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 8,100,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | Florida LFA 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 26,600,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 27,218,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 26,600,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 27,218,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 53,818,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | Florida LFA 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 10,440,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 10,440,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 10,440,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | Florida LFA 005 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 9,300,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 9,300,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 9,300,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLfa005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | Flordia LFA 006 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 9,300,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLFA006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLFA006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLFA006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 9,300,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLFA006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLFA006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLFA006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 9,300,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLFA006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | Florida LFA 007 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLFA007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 5,883,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLFA007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLFA007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLFA007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 5,883,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLFA007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLFA007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLFA007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 5,883,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLFA007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | Georgia LGA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaLGA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 3,800,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaLGA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaLGA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaLGA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 3,800,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaLGA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaLGA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaLGA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 3,800,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaLGA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | Georgia LGA 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaLGA002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,400,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaLGA002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaLGA002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaLGA002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,400,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaLGA002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaLGA002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaLGA002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,400,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaLGA002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | Maryland LMD 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandLmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 102,938,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandLmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandLmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandLmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 102,938,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandLmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandLmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandLmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 102,938,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandLmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | Maryland LMD 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandLmd002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 2,486,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandLmd002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandLmd002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandLmd002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 2,486,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandLmd002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandLmd002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (326,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandLmd002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 70 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,486,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandLmd002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | New Jersey LNJ 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyLnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 43,300,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyLnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyLnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 38,632,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyLnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 81,932,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyLnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyLnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (163,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyLnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [5] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 81,932,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyLnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | New York LNY 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 52,461,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,525,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 52,461,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 2,525,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 54,986,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | New York LNY 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLny002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 58,900,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLny002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLny002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (9,506,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLny002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 49,394,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLny002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLny002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLny002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 49,394,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLny002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | New York LNY 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLNY003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 3,277,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLNY003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLNY003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 3,825,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLNY003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 3,277,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLNY003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 3,825,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLNY003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLNY003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 7,102,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkLNY003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | Oregon LOR 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonLor001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 3,674,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonLor001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonLor001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 215,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonLor001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 3,674,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonLor001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 215,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonLor001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonLor001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 3,889,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonLor001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | Oregon LOR 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonLor002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 20,326,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonLor002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonLor002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (9,558,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonLor002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 10,768,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonLor002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonLor002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonLor002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 10,768,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonLor002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | Texas LTX 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasLtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 3,375,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasLtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasLtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasLtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 3,375,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasLtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasLtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasLtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 3,375,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasLtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | Texas LTX 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasLtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 3,621,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasLtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasLtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasLtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 3,621,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasLtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasLtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasLtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 3,621,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasLtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | Virginia LVA 001 Property 1 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaLva001Property1Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 60,814,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaLva001Property1Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaLva001Property1Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 27,115,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaLva001Property1Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 87,929,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaLva001Property1Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaLva001Property1Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (1,554,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaLva001Property1Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [5] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 87,929,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaLva001Property1Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | California LCA 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 28,464,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 2,836,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (11,000,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 17,464,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 2,836,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (2,409,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 20,300,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | California LCA 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 87,300,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (11,330,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 75,970,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 75,970,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | California LCA 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 68,155,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (21,405,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 46,750,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 46,750,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | California LCA 005 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 84,100,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 5,628,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 89,728,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 89,728,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | California LCA 006 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 59,100,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 59,100,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 59,100,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | California LCA 008 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 30,500,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 30,500,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 30,500,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | California LCA 009 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLCA009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 4,095,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLCA009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 8,323,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLCA009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,638,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLCA009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 4,095,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLCA009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 9,961,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLCA009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (3,507,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLCA009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 14,056,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaLCA009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Land | Virginia LVA 001 Property 2 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaLva001Property2Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 11,324,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaLva001Property2Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaLva001Property2Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (8,017,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaLva001Property2Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 3,307,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaLva001Property2Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaLva001Property2Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaLva001Property2Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 3,307,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaLva001Property2Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_LandMember |  |  |  |
Commercial Entertainment and Leisure Real Estate |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 129,798,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 248,396,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 89,411,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 129,781,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 337,824,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (85,812,000)us-gaap_RealEstateAccumulatedDepreciation / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate, Gross | 467,605,000us-gaap_RealEstateGrossAtCarryingValue / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Alabama EAL 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_AlabamaEal001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 277,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_AlabamaEal001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 359,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_AlabamaEal001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_AlabamaEal001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 277,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_AlabamaEal001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 358,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_AlabamaEal001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (97,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_AlabamaEal001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 635,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_AlabamaEal001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Alabama EAL 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_AlabamaEal002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 319,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_AlabamaEal002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 414,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_AlabamaEal002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_AlabamaEal002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 319,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_AlabamaEal002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 415,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_AlabamaEal002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (112,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_AlabamaEal002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 734,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_AlabamaEal002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Arizona EAZ 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 793,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,027,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 3,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 793,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,030,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (278,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,823,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Arizona EAZ 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 521,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 673,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 521,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 672,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (183,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,193,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Arizona EAZ 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 305,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 394,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 305,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 393,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (107,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 698,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Arizona EAZ 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 630,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 815,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 630,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 817,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (221,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,447,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Arizona EAZ 005 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 590,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 764,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 590,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 766,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (207,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,356,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Arizona EAZ 006 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 476,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 616,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 476,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 615,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (167,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,091,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Arizona EAZ 007 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 654,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 845,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 654,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 844,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (229,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,498,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Arizona EAZ 008 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 666,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 862,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 666,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 860,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (233,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,526,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Arizona EAZ 009 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 460,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 596,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 460,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 598,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (161,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,058,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaEaz009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | California ECA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,097,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,421,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 3,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,097,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,424,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (384,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,521,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | California ECA 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 434,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 560,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 434,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 562,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (152,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 996,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | California ECA 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 332,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 429,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 332,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 430,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (116,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 762,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | California ECA 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,642,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 2,124,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (4,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,642,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 2,120,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (575,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 3,762,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | California ECA 005 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 676,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 876,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 676,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 878,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (237,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,554,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | California ECA 006 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 720,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 932,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 720,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 934,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (252,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,654,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | California ECA 007 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 574,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 743,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 574,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 742,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (201,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,316,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | California ECA 008 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 392,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 508,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 392,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 507,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (137,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 899,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | California ECA 009 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 358,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 464,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 358,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 463,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (126,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 821,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | California ECA 010 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 18,000,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 18,000,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (4,760,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 18,000,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | California ECA 011 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 852,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,101,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 852,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,099,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (298,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,951,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | California ECA 012 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,572,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 2,034,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 5,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,572,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 2,039,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (551,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 3,611,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | California ECA 013 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,953,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 25,772,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 27,725,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (4,042,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 27,725,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | California ECA 014 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 659,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 852,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 659,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 850,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (231,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,509,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | California ECA 015 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 562,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 729,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 562,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 730,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (197,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,292,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | California ECA 016 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 896,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,159,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 896,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,157,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (314,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,053,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaEca016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Colorado ECO 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 466,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 602,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 466,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 601,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (163,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,067,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Colorado ECO 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 640,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 827,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 3,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 640,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 830,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (224,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,470,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Colorado ECO 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 729,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 944,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 729,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 946,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (255,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,675,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Colorado ECO 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 536,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 694,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 536,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 693,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (188,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,229,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Colorado ECO 005 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 412,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 533,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 412,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 535,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (144,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 947,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Colorado ECO 006 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 901,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,165,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 901,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,163,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (316,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,064,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoEco006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Connecticut ECT 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ConnecticutEct001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,097,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ConnecticutEct001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,420,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ConnecticutEct001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ConnecticutEct001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,097,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ConnecticutEct001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,418,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ConnecticutEct001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (385,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ConnecticutEct001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,515,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ConnecticutEct001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Connecticut ECT 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ConnecticutEct002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 330,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ConnecticutEct002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 426,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ConnecticutEct002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ConnecticutEct002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 330,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ConnecticutEct002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 427,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ConnecticutEct002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (115,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ConnecticutEct002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 757,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ConnecticutEct002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Delaware EDE 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_DelawareEde001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,076,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_DelawareEde001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,390,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_DelawareEde001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 7,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_DelawareEde001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,076,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_DelawareEde001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,397,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_DelawareEde001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (377,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_DelawareEde001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,473,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_DelawareEde001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Florida EFL 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 41,809,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 41,809,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (15,198,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 27 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 41,809,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Florida EFL 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 412,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 531,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 412,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 531,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (144,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 943,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Florida EFL 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 6,550,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 17,118,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 6,533,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 17,135,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (3,281,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 23,668,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Florida EFL 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,067,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,382,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 4,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,067,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,386,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (374,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,453,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Florida EFL 005 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 340,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 439,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 340,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 438,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (119,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 778,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Florida EFL 006 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 401,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 520,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 401,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 521,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (141,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 922,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Florida EFL 007 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 507,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 655,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 507,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 654,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (178,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,161,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Florida EFL 008 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 282,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 364,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 282,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 363,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (99,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 645,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Florida EFL 009 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 352,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 455,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 352,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 456,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (123,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 808,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Florida EFL 011 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 437,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 567,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 437,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 568,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (153,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,005,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Florida EFL 012 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 532,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 689,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 532,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 690,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (186,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,222,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Florida EFL 014 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 486,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 629,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 486,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 631,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (170,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,117,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Florida EFL 016 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 497,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 643,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 497,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 642,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (174,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,139,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Florida EFL 018 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 643,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 833,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 643,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 831,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (225,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,474,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Florida EFL 019 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl019Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 4,200,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl019Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 18,272,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl019Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl019Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 4,200,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl019Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 18,272,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl019Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (4,497,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl019Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 22,472,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl019Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Florida EFL 020 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl020Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 551,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl020Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 714,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl020Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl020Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 551,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl020Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 712,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl020Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (193,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl020Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,263,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl020Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Florida EFL 021 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl021Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 364,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl021Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 470,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl021Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl021Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 364,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl021Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 469,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl021Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (127,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl021Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 833,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl021Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Florida EFL 022 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl022Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 507,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl022Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 656,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl022Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl022Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 507,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl022Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 658,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl022Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (178,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl022Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,165,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl022Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Florida EFL 023 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl023Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl023Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 19,337,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl023Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl023Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl023Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 19,337,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl023Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (4,759,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl023Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 19,337,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaEfl023Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Georgia EGA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 510,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 660,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 510,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 658,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (179,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,168,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Georgia EGA 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 286,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 371,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 286,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 372,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (100,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 658,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Georgia EGA 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 474,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 613,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 474,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 614,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (166,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,088,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Georgia EGA 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 581,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 752,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 581,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 754,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (203,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,335,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Georgia EGA 005 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 718,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 930,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 718,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 928,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (252,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,646,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Georgia EGA 006 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 546,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 706,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 546,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 708,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (191,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,254,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Georgia EGA 007 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 502,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 651,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 502,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 650,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (176,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,152,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaEga007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Illinois EIL 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 335,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 434,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 335,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 435,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (117,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 770,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Illinois EIL 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 481,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 622,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 481,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 623,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (168,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,104,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Illinois EIL 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 8,803,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 57,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 30,479,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 8,803,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 30,536,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (5,583,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 39,339,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Illinois EIL 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 433,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 560,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 433,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 558,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (152,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 991,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Illinois EIL 005 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 431,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 557,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 431,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 556,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (151,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 987,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisEil005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Indiana EIN 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IndianaEin001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 542,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IndianaEin001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 701,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IndianaEin001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IndianaEin001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 542,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IndianaEin001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 700,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IndianaEin001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (190,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IndianaEin001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,242,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IndianaEin001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Kentucky EKY 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_KentuckyEky001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 417,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_KentuckyEky001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 539,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_KentuckyEky001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_KentuckyEky001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 417,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_KentuckyEky001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 540,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_KentuckyEky001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (146,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_KentuckyEky001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 957,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_KentuckyEky001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Kentucky EKY 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_KentuckyEky002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 365,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_KentuckyEky002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 473,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_KentuckyEky002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_KentuckyEky002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 365,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_KentuckyEky002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 472,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_KentuckyEky002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (128,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_KentuckyEky002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 837,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_KentuckyEky002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Massachusetts EMA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 523,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 678,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 523,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 676,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (183,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,199,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Massachusetts EMA 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 548,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 711,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 548,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 712,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (192,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,260,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Massachusetts EMA 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 519,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 672,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 519,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 670,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (182,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,189,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Massachusetts EMA 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 344,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 445,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 344,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 446,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (120,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 790,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MassachusettsEma004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Maryland EMD 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 428,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 554,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 428,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 555,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (150,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 983,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Maryland EMD 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 575,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 745,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 575,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 747,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (202,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,322,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Maryland EMD 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 362,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 468,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 362,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 467,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (127,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 829,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Maryland EMD 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 884,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,145,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (3,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 884,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,142,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (310,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,026,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Maryland EMD 006 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 399,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 518,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 399,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 517,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (140,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 916,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Maryland EMD 007 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 649,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 839,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 649,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 837,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (227,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,486,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Maryland EMD 008 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 366,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 473,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 366,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 473,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (128,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 839,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Maryland EMD 009 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 398,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 516,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 398,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 515,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (140,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 913,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEmd009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Maryland EMD 011 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEMD011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,126,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEMD011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,458,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEMD011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 3,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEMD011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,126,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEMD011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,461,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEMD011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (394,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEMD011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,587,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MarylandEMD011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Michigan EMI 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 516,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 667,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 516,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 666,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (181,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,182,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Michigan EMI 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 554,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 718,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 554,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 720,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (194,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,274,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Michigan EMI 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 387,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 500,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 387,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 499,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (136,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 886,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Michigan EMI 005 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 533,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 691,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 533,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 689,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (187,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,222,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MichiganEmi005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Minnesota EMN 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 666,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 861,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 666,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 859,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (233,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,525,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Minnesota EMN 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 2,962,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 15,384,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 2,962,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 15,384,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (3,078,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 18,346,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Minnesota EMN 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 2,437,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 8,715,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 679,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 2,437,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 9,394,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (2,292,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 11,831,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MinnesotaEmn004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Missouri EMO 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 334,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 432,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 334,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 433,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (117,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 767,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Missouri EMO 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 404,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 523,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 404,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 521,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (142,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 925,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Missouri EMO 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 462,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 597,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 462,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 596,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (162,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,058,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Missouri EMO 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 878,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,139,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 3,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 878,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,142,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (308,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,020,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_MissouriEmo004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | North Carolina ENC 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 397,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 513,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 397,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 514,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (139,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 911,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | North Carolina ENC 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 476,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 615,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 476,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 614,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (167,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,090,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | North Carolina ENC 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 410,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 530,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 410,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 529,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (144,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 939,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | North Carolina ENC 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 402,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 520,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 402,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 519,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (141,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 921,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | North Carolina ENC 005 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 948,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,227,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 3,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 948,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,230,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (332,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,178,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | North Carolina ENC 006 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 259,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 336,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 259,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 335,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (91,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 594,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | North Carolina ENC 007 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 349,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 452,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 349,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 453,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (122,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 802,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | North Carolina ENC 008 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 640,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 828,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 640,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 830,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (224,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,470,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | North Carolina ENC 009 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaENC009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 409,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaENC009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 531,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaENC009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaENC009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 409,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaENC009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 532,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaENC009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (143,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaENC009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 941,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaENC009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | North Carolina Enc 010 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 965,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,249,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (3,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 965,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,246,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (338,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,211,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | North Carolina ENC 011 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 475,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 615,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 475,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 616,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (166,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,091,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | North Carolina ENC 012 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 494,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 638,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 494,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 637,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (173,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,131,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NorthCarolinaEnc012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | New Jersey ENJ 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyEnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,560,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyEnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 2,019,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyEnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (4,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyEnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,560,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyEnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 2,015,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyEnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (547,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyEnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 3,575,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyEnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | New Jersey ENJ 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyEnj002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 830,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyEnj002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,075,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyEnj002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyEnj002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 830,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyEnj002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,077,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyEnj002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (291,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyEnj002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,907,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyEnj002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Nevada ENV 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NevadaEnv001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 440,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NevadaEnv001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 569,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NevadaEnv001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NevadaEnv001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 440,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NevadaEnv001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 568,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NevadaEnv001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (154,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NevadaEnv001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,008,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NevadaEnv001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | New York ENY 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 603,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 779,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 603,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 778,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (211,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,381,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | New York ENY 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 442,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 571,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 442,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 573,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (155,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,015,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | New York ENY 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 385,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 499,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 385,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 498,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (135,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 883,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | New York ENY 005 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 350,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 453,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 350,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 454,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (123,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 804,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | New York ENY 006 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 326,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 421,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 326,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 423,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (114,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 749,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | New York ENY 007 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 494,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 640,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 494,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 642,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (173,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,136,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | New York ENY 008 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 320,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 414,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 320,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 413,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (112,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 733,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | New York ENY 009 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 399,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 516,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 399,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 515,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (140,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 914,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | New York ENY 010 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 959,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,240,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (3,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 959,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,237,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (336,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,196,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | New York ENY 011 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 587,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 761,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 587,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 763,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (206,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,350,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | New York ENY 012 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 521,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 675,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 521,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 673,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (183,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,194,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | New York ENY 013 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 711,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 920,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 711,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 922,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (249,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,633,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | New York ENY 014 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 558,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 723,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 558,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 721,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (196,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,279,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | New York ENY 015 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 747,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 967,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 3,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 747,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 970,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (262,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,717,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny015Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | New York ENY 016 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 683,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 885,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 683,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 883,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (240,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,566,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny016Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | New York ENY 017 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,492,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,933,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 4,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,492,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,937,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (523,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 3,429,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | New York ENY 018 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,471,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,904,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (4,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,471,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,900,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (516,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 3,371,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkEny018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Ohio EOH 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 434,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 562,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 434,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 563,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (152,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 997,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Ohio EOH 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 967,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,252,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 967,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,250,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (339,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,217,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Ohio EOH 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 281,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 365,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 281,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 364,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (99,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 645,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Ohio EOH 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 393,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 508,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 393,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 510,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (138,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 903,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OhioEoh004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Oklahoma EOK 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OklahomaEok001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 431,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OklahomaEok001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 557,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OklahomaEok001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OklahomaEok001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 431,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OklahomaEok001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 556,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OklahomaEok001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (151,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OklahomaEok001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 987,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OklahomaEok001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Oklahoma EOK 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OklahomaEok002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 954,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OklahomaEok002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,235,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OklahomaEok002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 3,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OklahomaEok002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 954,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OklahomaEok002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,238,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OklahomaEok002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (334,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OklahomaEok002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,192,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OklahomaEok002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Oregon EOR 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonEor002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 393,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonEor002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 508,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonEor002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonEor002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 393,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonEor002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 507,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonEor002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (138,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonEor002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 900,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_OregonEor002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Pennsylvania EPA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 407,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 527,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 407,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 528,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (143,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 935,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Pennsylvania EPA 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 421,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 544,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 421,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 546,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (147,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 967,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Pennsylvania EPA 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 409,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 528,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 409,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 527,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (143,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 936,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Pennsylvania EPA 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 407,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 527,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 407,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 526,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (143,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 933,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaEpa004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Puerto Rico EPR 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PuertoRicoEpr001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 950,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PuertoRicoEpr001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,230,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PuertoRicoEpr001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 3,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PuertoRicoEpr001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 950,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PuertoRicoEpr001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,233,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PuertoRicoEpr001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (333,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PuertoRicoEpr001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,183,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PuertoRicoEpr001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Rhode Island ERI 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_RhodeIslandEri001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 850,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_RhodeIslandEri001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,100,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_RhodeIslandEri001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_RhodeIslandEri001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 850,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_RhodeIslandEri001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,098,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_RhodeIslandEri001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (298,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_RhodeIslandEri001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,948,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_RhodeIslandEri001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | South Carolina ESC 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaEsc002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 332,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaEsc002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 429,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaEsc002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaEsc002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 332,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaEsc002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 430,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaEsc002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (116,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaEsc002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 762,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaEsc002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | South Carolina ESC 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaEsc003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 924,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaEsc003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,196,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaEsc003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 3,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaEsc003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 924,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaEsc003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,199,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaEsc003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (324,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaEsc003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,123,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaEsc003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Tennessee ETN 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TennesseeEtn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 260,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TennesseeEtn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 338,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TennesseeEtn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TennesseeEtn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 260,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TennesseeEtn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 338,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TennesseeEtn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (91,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TennesseeEtn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 598,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TennesseeEtn001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Texas ETX 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,045,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,353,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 3,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,045,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,356,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (366,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,401,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Texas ETX 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 593,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 767,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 593,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 765,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (208,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,358,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Texas ETX 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 838,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,083,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 838,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,081,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (294,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,919,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Texas ETX 005 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 528,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 682,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 528,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 681,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (185,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,209,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Texas ETX 006 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 480,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 622,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 480,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 621,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (168,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,101,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Texas ETX 007 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 975,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,261,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (3,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 975,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,258,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (342,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,233,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Texas ETX 008 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,108,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,433,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (3,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,108,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,430,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (388,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,538,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Texas ETX 009 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 425,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 549,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (56,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 425,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 493,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (140,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 918,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Texas ETX 010 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 518,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 671,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 518,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 673,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (182,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,191,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Texas ETX 011 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 758,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 981,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 3,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 758,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 984,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (266,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,742,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Texas ETX 013 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 375,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 485,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 375,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 484,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (131,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 859,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Texas ETX 014 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 438,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 567,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 438,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 566,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (154,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,004,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx014Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Texas ETX 017 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 561,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 726,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 561,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 728,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (196,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,289,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx017Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Texas ETX 018 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 753,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 976,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 753,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 978,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (264,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,731,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx018Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Texas ETX 019 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx019Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 521,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx019Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 675,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx019Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx019Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 521,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx019Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 677,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx019Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (183,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx019Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,198,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx019Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Texas ETX 020 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx020Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 634,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx020Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 821,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx020Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx020Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 634,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx020Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 820,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx020Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (222,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx020Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,454,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx020Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Texas ETX 021 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx021Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 379,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx021Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 491,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx021Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx021Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 379,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx021Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 490,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx021Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (133,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx021Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 869,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx021Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Texas ETX 022 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx022Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 592,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx022Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 766,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx022Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx022Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 592,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx022Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 768,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx022Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (207,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx022Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,360,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasEtx022Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Utah EUT 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahEut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 624,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahEut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 808,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahEut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahEut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 624,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahEut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 810,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahEut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (219,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahEut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,434,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahEut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Virginia EVA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,134,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,467,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 4,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,134,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,471,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (397,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,605,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Virginia EVA 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 845,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,094,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 845,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,096,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (296,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,941,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Virginia EVA 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 884,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,145,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 884,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,143,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (310,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,027,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Virginia EVA 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 953,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,233,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (3,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 953,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,230,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (334,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,183,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Virginia EVA 005 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 487,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 632,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 487,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 633,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (171,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,120,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Virginia EVA 006 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 425,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 550,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 425,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 549,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (149,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 974,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Virginia EVA 007 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,151,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,490,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (3,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,151,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,487,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (403,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,638,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva007Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Virginia EVA 008 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 546,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 707,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 546,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 709,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (191,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,255,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva008Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Virginia EVA 009 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 851,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,103,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 3,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 851,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,106,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (298,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,957,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva009Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Virginia EVA 010 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 819,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,061,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 819,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,063,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (287,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,882,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva010Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Virginia EVA 011 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 958,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,240,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 3,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 958,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,243,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (336,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,201,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva011Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Virginia EVA 012 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 788,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,020,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 788,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,018,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (276,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,806,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva012Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Virginia EVA 013 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 554,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 716,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 554,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 715,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (194,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,269,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaEva013Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Washington EWA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonEwa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,500,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonEwa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 6,500,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonEwa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonEwa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,500,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonEwa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 6,500,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonEwa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (2,116,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonEwa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 8,000,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonEwa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Wisconsin EWI 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 521,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 673,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 4,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 521,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 677,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (183,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,198,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Wisconsin EWI 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 413,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 535,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 413,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 537,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (145,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 950,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Wisconsin EWI 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 542,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 702,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 542,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 700,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (190,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,242,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Wisconsin EWI 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 793,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,025,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 793,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,023,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (278,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,816,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Commercial Entertainment and Leisure Real Estate | Wisconsin EWI 005 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,124,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,455,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 10,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,124,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,465,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (394,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,589,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WisconsinEwi005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_CommercialEntertainmentAndLeisureRealEstateMember |  |  |  |
Retail Site [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 58,835,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 154,415,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 27,654,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 57,908,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 182,996,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (23,156,000)us-gaap_RealEstateAccumulatedDepreciation / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate, Gross | 240,904,000us-gaap_RealEstateGrossAtCarryingValue / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
Retail Site [Member] | Arizona RAZ 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 2,625,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 4,875,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,355,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 2,625,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 6,230,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (515,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 8,855,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
Retail Site [Member] | Arizona RAZ 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 2,184,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 4,056,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (1,588,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 2,184,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 2,468,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (194,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 4,652,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
Retail Site [Member] | Arizona RAZ 005 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 2,657,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 2,666,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (277,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 2,657,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 2,389,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (326,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 5,046,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaRaz005Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
Retail Site [Member] | California RCA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaRca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 2,569,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaRca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 3,031,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaRca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 370,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaRca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 2,569,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaRca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 3,401,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaRca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (413,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaRca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 5,970,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaRca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
Retail Site [Member] | Colorado RCO 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoRco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 2,631,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoRco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 279,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoRco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 5,195,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoRco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 2,607,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoRco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 5,498,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoRco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (1,048,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoRco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 8,105,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ColoradoRco001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
Retail Site [Member] | Florida RFL 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaRfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 3,950,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaRfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaRfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 10,285,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaRfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 3,908,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaRfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 10,327,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaRfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (2,147,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaRfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 14,235,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaRfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
Retail Site [Member] | Hawaii RHI 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiRhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 3,393,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiRhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 21,155,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiRhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (10,144,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiRhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 3,393,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiRhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 11,011,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiRhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (1,895,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiRhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 14,404,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiRhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
Retail Site [Member] | Illinois RIL 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisRil001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisRil001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 336,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisRil001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,193,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisRil001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisRil001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,529,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisRil001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (406,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisRil001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,529,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisRil001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
Retail Site [Member] | Illinois RIL 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisRIL002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 14,934,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisRIL002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 29,675,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisRIL002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 5,606,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisRIL002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 14,934,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisRIL002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 35,281,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisRIL002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (2,961,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisRIL002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 50,215,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_IllinoisRIL002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
Retail Site [Member] | New Mexico RNM 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewMexicoRnm001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,733,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewMexicoRnm001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewMexicoRnm001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 8,370,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewMexicoRnm001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,705,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewMexicoRnm001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 8,398,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewMexicoRnm001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (1,592,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewMexicoRnm001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 10,103,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewMexicoRnm001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
Retail Site [Member] | New York RNY 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkRny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 731,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkRny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 6,073,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkRny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 699,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkRny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 711,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkRny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 6,792,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkRny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (1,725,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkRny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 7,503,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewYorkRny001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
Retail Site [Member] | Pennsylvania RPA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaRpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 5,687,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaRpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 56,950,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaRpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,367,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaRpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 5,687,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaRpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 59,317,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaRpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (6,264,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaRpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 65,004,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaRpa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
Retail Site [Member] | South Carolina RSC 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaRsc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 2,126,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaRsc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 948,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaRsc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (723,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaRsc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,337,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaRsc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,014,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaRsc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (185,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaRsc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,351,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_SouthCarolinaRsc001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
Retail Site [Member] | Texas RTX 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 3,538,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 4,215,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 171,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 3,514,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 4,410,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (1,249,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 7,924,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
Retail Site [Member] | Texas RTX 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 1,225,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 2,275,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (791,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,225,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 1,484,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,709,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
Retail Site [Member] | Texas RTX 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 630,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 1,170,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (409,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 630,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 761,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,391,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_TexasRtx003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
Retail Site [Member] | Utah RUT 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahRut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 3,502,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahRut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahRut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 5,975,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahRut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 3,502,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahRut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 5,975,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahRut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (1,226,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahRut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 9,477,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_UtahRut001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [4] |  |  |
Retail Site [Member] | Virginia RVA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaRVA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 4,720,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaRVA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 16,711,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaRVA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaRVA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 4,720,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaRVA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 16,711,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaRVA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (1,010,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaRVA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 21,431,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_VirginiaRVA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_RetailSiteMember |  |  |  |
Residential Real Estate |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 191,386,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 501,461,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (577,095,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 33,597,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 82,155,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate, Gross | 115,752,000us-gaap_RealEstateGrossAtCarryingValue / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
Residential Real Estate | Arizona AAZ 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaAaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 2,423,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaAaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaAaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 13,372,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaAaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 2,423,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaAaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 13,372,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaAaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaAaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 15,795,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaAaz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
Residential Real Estate | California ACA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaAca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 7,333,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaAca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 29,333,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaAca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (33,290,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaAca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 675,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaAca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 2,701,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaAca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaAca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 3,376,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaAca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
Residential Real Estate | California ACA 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaAca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 10,078,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaAca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 40,312,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaAca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (43,252,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaAca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,428,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaAca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 5,710,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaAca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaAca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 7,138,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaAca002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
Residential Real Estate | Florida AFL 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 2,394,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 24,206,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (26,420,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 16,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 164,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 180,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
Residential Real Estate | Florida AFL 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 6,540,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 15,260,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (21,800,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 0us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 0us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
Residential Real Estate | Florida AFL003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 30,900,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 30,900,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (56,430,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 2,685,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 2,685,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 5,370,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaAfl003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
Residential Real Estate | Georgia AGA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaAGA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 2,963,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaAGA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 11,850,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaAGA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 10,323,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaAGA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 5,027,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaAGA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 20,109,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaAGA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaAGA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 25,136,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaAGA001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [4] |  |  |
Residential Real Estate | Hawaii AHI 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiAhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 8,080,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiAhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 12,120,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiAhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (18,535,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiAhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 666,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiAhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 999,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiAhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiAhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 1,665,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiAhi001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
Residential Real Estate | Hawaii AHI 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiAHI003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 3,483,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiAHI003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 9,417,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiAHI003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (12,417,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiAHI003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 130,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiAHI003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 353,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiAHI003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiAHI003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 483,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_HawaiiAHI003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
Residential Real Estate | New Jersey ANJ 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyAnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 36,405,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyAnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 64,719,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyAnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (100,639,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyAnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 175,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyAnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 310,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyAnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyAnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 485,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NewJerseyAnj001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
Residential Real Estate | Nevada ANZ 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NevadaAnz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 18,117,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NevadaAnz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 106,829,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NevadaAnz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (117,328,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NevadaAnz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 1,104,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NevadaAnz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 6,514,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NevadaAnz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NevadaAnz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 7,618,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_NevadaAnz001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
Residential Real Estate | Pennsylvania APA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaApa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 44,438,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaApa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 82,527,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaApa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (117,620,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaApa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 3,271,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaApa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 6,074,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaApa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaApa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 9,345,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaApa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [4] |  |  |
Residential Real Estate | Pennsylvania APA 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaApa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 15,890,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaApa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 29,510,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaApa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (8,356,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaApa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 15,891,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaApa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 21,153,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaApa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaApa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 37,044,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_PennsylvaniaApa002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
Residential Real Estate | Washington AWA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonAwa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 2,342,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonAwa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 44,478,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonAwa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (44,703,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonAwa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 106,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonAwa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 2,011,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonAwa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | 0us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonAwa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 0 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 2,117,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_WashingtonAwa001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = us-gaap_ResidentialRealEstateMember |  |  |  |
Mixed Use Collateral |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 53,918,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 123,011,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 24,345,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 53,766,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 147,508,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (12,940,000)us-gaap_RealEstateAccumulatedDepreciation / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate, Gross | 201,274,000us-gaap_RealEstateGrossAtCarryingValue / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
Mixed Use Collateral | Flordia LFA 006 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaLFA006Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
Mixed Use Collateral | Arizona MAZ 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaMaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 10,182,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaMaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 52,544,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaMaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 20,731,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaMaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 10,030,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaMaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 73,427,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaMaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (8,752,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaMaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 83,457,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_ArizonaMaz002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
Mixed Use Collateral | California MCA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaMca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 5,869,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaMca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 629,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaMca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaMca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 5,870,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaMca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 630,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaMca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (262,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaMca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 6,500,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_CaliforniaMca001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
Mixed Use Collateral | Florida MFL 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 8,450,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 8,216,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | (2,405,000)us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 8,450,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 5,811,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (1,742,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 14,261,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMfl001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
Mixed Use Collateral | Florida MFL 002 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 18,229,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 20,899,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,637,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 18,229,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 22,536,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (729,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 40,765,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL002Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
Mixed Use Collateral | Florida MFL 003 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 2,507,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 8,155,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 1,224,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 2,507,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 9,379,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (332,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 11,886,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL003Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
Mixed Use Collateral | Florida MFL 004 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 4,201,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 14,652,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 882,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember | [1] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 4,201,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 15,534,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (418,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | 19,735,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_FloridaMFL004Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember |  |  |  |
Mixed Use Collateral | Georgia MGA 001 [Member] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Amount of Encumbrances | 0us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaMga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Land | 4,480,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaMga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Initial Cost of Buildings and Improvements | 17,916,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaMga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,274,000us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaMga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember | [1],[4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Land | 4,479,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaMga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Carrying Amount of Buildings and Improvements | 20,191,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaMga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember | [4] |  |  |
SEC Schedule III, Real Estate Accumulated Depreciation | (705,000)us-gaap_RealEstateAccumulatedDepreciation / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaMga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember | [4] |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 40 years |  |  |  |
SEC Schedule III, Real Estate, Gross | $ 24,670,000us-gaap_RealEstateGrossAtCarryingValue / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = star_GeorgiaMga001Member / star_RealEstateAndAccumulatedDepreciationTypeOfPropertyAxis = star_MixedUseCollateralMember | [4] |  |  |
Minimum | Land |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 15 years |  |  |  |
Maximum [Member] | Land |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation | 20 years |  |  |  |
[1] | Includes impairments and unit sales.
[2] | Includes $13.1 million relating to accumulated depreciation for real estate assets held for sale as of December 31, 2014.
[3] | The aggregate cost for Federal income tax purposes was approximately $3.78 billion at December 31, 2014.
[4] | Consists of properties pledged as collateral under the Company's secured credit facilities with a total book value of $381.6 million
[5] | These properties have land improvements which have depreciable lives of 15 to 20 years.

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