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Schedule III - Real Estate and Accumulated Depreciation (Details) (USD $)
 12 Months Ended
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.