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Schedule III - Real Estate and Accumulated Depreciation and Amortization Under Operating Leases - Table 26 (Details) (USD $) In Thousands, unless otherwise specified | 12 Months Ended |  |  |
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Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | $ 5,236,251 us-gaap_RealEstateGrossAtCarryingValue |  | $ 4,686,844 us-gaap_RealEstateGrossAtCarryingValue | $ 4,145,368 us-gaap_RealEstateGrossAtCarryingValue | $ 3,531,845 us-gaap_RealEstateGrossAtCarryingValue
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 513,175 us-gaap_RealEstateAccumulatedDepreciation |  | 418,136 us-gaap_RealEstateAccumulatedDepreciation | 333,778 us-gaap_RealEstateAccumulatedDepreciation | 270,621 us-gaap_RealEstateAccumulatedDepreciation
Operating Lease |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 26,000 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 1,787,519 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 2,915,411 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 536,524 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 1,785,779 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 3,414,698 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 5,200,477 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 511,702 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember |  |  |  |
Operating Lease | United Rentals Perrysburg, OH |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsPerrysburgOhMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 642 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsPerrysburgOhMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 1,119 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsPerrysburgOhMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsPerrysburgOhMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsPerrysburgOhMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 642 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsPerrysburgOhMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 1,119 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsPerrysburgOhMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,761 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsPerrysburgOhMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 281 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsPerrysburgOhMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | United Rentals Plano, TX |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsPlanoTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 1,030 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsPlanoTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 1,148 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsPlanoTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsPlanoTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsPlanoTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 1,030 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsPlanoTxMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 1,148 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsPlanoTxMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 2,178 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsPlanoTxMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 288 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsPlanoTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | United Rentals Temple, TX |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsTempleTxMember | [3] |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 1,160 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsTempleTxMember | [3] |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 1,360 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsTempleTxMember | [3] |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsTempleTxMember | [3] |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsTempleTxMember | [3] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 1,160 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsTempleTxMember | [1],[2],[3] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 1,360 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsTempleTxMember | [1],[2],[3] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 2,520 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsTempleTxMember | [1],[2],[3] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 342 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsTempleTxMember | [3] |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years | [3] |  |  |
Operating Lease | United Rentals Ft. Worth, TX 1 |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsFtWorthTx1Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 1,428 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsFtWorthTx1Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 0 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsFtWorthTx1Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsFtWorthTx1Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsFtWorthTx1Member |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 1,428 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsFtWorthTx1Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,428 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsFtWorthTx1Member | [1],[2] |  |  |
Operating Lease | United Rentals Ft. Worth, TX 2 |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsFtWorthTx2Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 510 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsFtWorthTx2Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 1,128 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsFtWorthTx2Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsFtWorthTx2Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsFtWorthTx2Member |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 510 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsFtWorthTx2Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 1,128 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsFtWorthTx2Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,638 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsFtWorthTx2Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 281 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsFtWorthTx2Member |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | United Rentals Melbourne, FL |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsMelbourneFlMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 747 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsMelbourneFlMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 607 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsMelbourneFlMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsMelbourneFlMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsMelbourneFlMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 747 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsMelbourneFlMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 607 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsMelbourneFlMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,354 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsMelbourneFlMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 146 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UnitedRentalsMelbourneFlMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | University of Phoenix Glen Allen, VA |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UniversityOfPhoenixGlenAllenVaMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 2,177 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UniversityOfPhoenixGlenAllenVaMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 2,600 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UniversityOfPhoenixGlenAllenVaMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 670 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UniversityOfPhoenixGlenAllenVaMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UniversityOfPhoenixGlenAllenVaMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 2,177 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UniversityOfPhoenixGlenAllenVaMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 3,270 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UniversityOfPhoenixGlenAllenVaMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 5,447 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UniversityOfPhoenixGlenAllenVaMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 1,309 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_UniversityOfPhoenixGlenAllenVaMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Land Indianapolis, IN |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandIndianapolisINMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 640 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandIndianapolisINMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 1,107 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandIndianapolisINMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 62 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandIndianapolisINMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandIndianapolisINMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 700 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandIndianapolisINMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 700 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandIndianapolisINMember | [1],[2] |  |  |
Operating Lease | Vacant Land Southfield, MI |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandSouthfieldMIMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 405 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandSouthfieldMIMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 644 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandSouthfieldMIMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandSouthfieldMIMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandSouthfieldMIMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 497 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandSouthfieldMIMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 497 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandSouthfieldMIMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 39 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandSouthfieldMIMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 15 years |  |  |  |
Operating Lease | Vacant Land Tucson, AZ |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandTucsonAZMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 1,156 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandTucsonAZMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 0 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandTucsonAZMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandTucsonAZMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandTucsonAZMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 707 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandTucsonAZMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 707 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandTucsonAZMember | [1],[2] |  |  |
Operating Lease | Vacant Land Bonita Springs, FL |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandBonitaSpringsFlMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 112 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandBonitaSpringsFlMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 0 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandBonitaSpringsFlMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandBonitaSpringsFlMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandBonitaSpringsFlMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 25 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandBonitaSpringsFlMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 25 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandBonitaSpringsFlMember | [1],[2] |  |  |
Operating Lease | Vacant Land Lancaster, OH |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandLancasterOhMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 1,035 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandLancasterOhMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 0 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandLancasterOhMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandLancasterOhMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandLancasterOhMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 218 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandLancasterOhMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 218 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandLancasterOhMember | [1],[2] |  |  |
Operating Lease | Vacant Land Bakersfield, CA |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandBakersfieldCaMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 3,303 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandBakersfieldCaMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 3,845 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandBakersfieldCaMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandBakersfieldCaMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandBakersfieldCaMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 1,826 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandBakersfieldCaMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,826 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantLandBakersfieldCaMember | [1],[2] |  |  |
Operating Lease | Vacant Property Orlando, FL |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyOrlandoFLMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 820 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyOrlandoFLMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 2,441 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyOrlandoFLMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 6 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyOrlandoFLMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyOrlandoFLMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 820 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyOrlandoFLMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 2,448 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyOrlandoFLMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 3,268 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyOrlandoFLMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 1,259 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyOrlandoFLMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property Homestead, PA |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHomesteadPaMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 1,139 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHomesteadPaMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 0 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHomesteadPaMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 2,158 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHomesteadPaMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHomesteadPaMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 1,139 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHomesteadPaMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 2,158 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHomesteadPaMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 3,297 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHomesteadPaMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 650 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHomesteadPaMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 31 years |  |  |  |
Operating Lease | Vacant Property Kenosha, WI |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyKenoshaWIMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 1,918 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyKenoshaWIMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 3,431 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyKenoshaWIMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyKenoshaWIMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyKenoshaWIMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 1,918 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyKenoshaWIMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 3,431 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyKenoshaWIMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 5,349 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyKenoshaWIMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 1,529 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyKenoshaWIMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property Conyers, GA |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyConyersGaMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 320 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyConyersGaMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 556 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyConyersGaMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyConyersGaMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyConyersGaMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 320 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyConyersGaMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 556 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyConyersGaMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 876 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyConyersGaMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 244 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyConyersGaMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property Harlingen, TX |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHarlingenTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 317 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHarlingenTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 756 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHarlingenTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 120 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHarlingenTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHarlingenTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 317 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHarlingenTXMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 876 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHarlingenTXMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,193 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHarlingenTXMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 303 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHarlingenTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property Alpharetta, GA |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyAlpharettaGAMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 3,033 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyAlpharettaGAMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 1,642 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyAlpharettaGAMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyAlpharettaGAMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyAlpharettaGAMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 3,033 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyAlpharettaGAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 1,642 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyAlpharettaGAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 4,675 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyAlpharettaGAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 535 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyAlpharettaGAMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property Burton, MI |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBurtonMIMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 620 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBurtonMIMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 707 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBurtonMIMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBurtonMIMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBurtonMIMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 620 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBurtonMIMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 707 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBurtonMIMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,327 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBurtonMIMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 231 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBurtonMIMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property Hammond, LA |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHammondLAMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 248 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHammondLAMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 814 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHammondLAMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 62 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHammondLAMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHammondLAMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 248 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHammondLAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 627 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHammondLAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 875 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHammondLAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 217 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHammondLAMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property Kennedale, TX |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyKennedaleTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 400 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyKennedaleTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 692 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyKennedaleTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyKennedaleTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyKennedaleTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 391 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyKennedaleTXMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 692 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyKennedaleTXMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,083 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyKennedaleTXMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 226 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyKennedaleTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property Lewisville, TX |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLewisvilleTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 1,370 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLewisvilleTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 1,019 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLewisvilleTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLewisvilleTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLewisvilleTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 1,370 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLewisvilleTXMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 1,019 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLewisvilleTXMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 2,389 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLewisvilleTXMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 332 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLewisvilleTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property Mesa, AZ |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyMesaAZMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 153 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyMesaAZMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 400 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyMesaAZMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyMesaAZMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyMesaAZMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 153 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyMesaAZMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 400 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyMesaAZMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 553 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyMesaAZMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 131 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyMesaAZMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property Montgomery, AL |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyMontgomeryALMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 1,418 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyMontgomeryALMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 1,140 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyMontgomeryALMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyMontgomeryALMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyMontgomeryALMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 1,418 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyMontgomeryALMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 1,044 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyMontgomeryALMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 2,462 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyMontgomeryALMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 347 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyMontgomeryALMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property S. Beaumont, TX |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyS.BeaumontTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 439 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyS.BeaumontTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 1,363 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyS.BeaumontTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyS.BeaumontTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyS.BeaumontTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 439 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyS.BeaumontTXMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 1,363 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyS.BeaumontTXMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,802 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyS.BeaumontTXMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 445 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyS.BeaumontTXMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property Swansea, IL |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertySwanseaIlMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 46 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertySwanseaIlMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 133 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertySwanseaIlMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 57 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertySwanseaIlMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertySwanseaIlMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 46 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertySwanseaIlMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 190 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertySwanseaIlMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 236 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertySwanseaIlMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 25 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertySwanseaIlMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property Tacoma, WA |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyTacomaWAMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 527 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyTacomaWAMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 795 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyTacomaWAMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyTacomaWAMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyTacomaWAMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 527 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyTacomaWAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 795 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyTacomaWAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,322 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyTacomaWAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 259 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyTacomaWAMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property Woodstock, GA |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyWoodstockGaMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 1,937 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyWoodstockGaMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 1,285 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyWoodstockGaMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyWoodstockGaMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyWoodstockGaMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 1,297 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyWoodstockGaMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 277 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyWoodstockGaMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,574 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyWoodstockGaMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 277 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyWoodstockGaMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property St. Louis, MO |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertySt.LouisMOMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 556 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertySt.LouisMOMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 3,688 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertySt.LouisMOMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertySt.LouisMOMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertySt.LouisMOMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 556 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertySt.LouisMOMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 3,688 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertySt.LouisMOMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 4,244 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertySt.LouisMOMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 965 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertySt.LouisMOMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property Hudson Falls, NY |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHudsonFallsNyMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 57 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHudsonFallsNyMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 780 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHudsonFallsNyMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 39 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHudsonFallsNyMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHudsonFallsNyMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 57 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHudsonFallsNyMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 819 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHudsonFallsNyMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 876 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHudsonFallsNyMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 209 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyHudsonFallsNyMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property Columbus, OH |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyColumbusOHMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 1,596 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyColumbusOHMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 934 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyColumbusOHMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 13 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyColumbusOHMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyColumbusOHMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 1,605 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyColumbusOHMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 939 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyColumbusOHMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 2,544 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyColumbusOHMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 238 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyColumbusOHMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property Ft. Worth, TX 1 |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFt.WorthTX1Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 2,505 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFt.WorthTX1Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 2,138 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFt.WorthTX1Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFt.WorthTX1Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFt.WorthTX1Member |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 2,505 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFt.WorthTX1Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 2,138 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFt.WorthTX1Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 4,643 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFt.WorthTX1Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 528 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFt.WorthTX1Member |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property Ft. Worth, TX 2 |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFt.WorthTX2Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 988 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFt.WorthTX2Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 2,368 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFt.WorthTX2Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFt.WorthTX2Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFt.WorthTX2Member |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 988 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFt.WorthTX2Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 2,368 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFt.WorthTX2Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 3,356 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFt.WorthTX2Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 585 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFt.WorthTX2Member |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property Dallas, PA |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyDallasPAMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 214 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyDallasPAMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 345 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyDallasPAMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyDallasPAMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyDallasPAMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 214 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyDallasPAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 345 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyDallasPAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 559 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyDallasPAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 162 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyDallasPAMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 20 years |  |  |  |
Operating Lease | Vacant Property Abbottstown, PA |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyAbbottstownPAMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 55 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyAbbottstownPAMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 200 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyAbbottstownPAMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyAbbottstownPAMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyAbbottstownPAMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 55 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyAbbottstownPAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 200 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyAbbottstownPAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 255 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyAbbottstownPAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 45 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyAbbottstownPAMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property Carlisle, PA |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyCarlislePAMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 87 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyCarlislePAMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 103 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyCarlislePAMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyCarlislePAMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyCarlislePAMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 87 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyCarlislePAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 103 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyCarlislePAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 190 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyCarlislePAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 22 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyCarlislePAMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property Indianapolis, IN |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyIndianapolisINMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 223 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyIndianapolisINMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 483 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyIndianapolisINMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 59 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyIndianapolisINMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyIndianapolisINMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 223 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyIndianapolisINMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 542 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyIndianapolisINMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 765 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyIndianapolisINMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 214 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyIndianapolisINMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 20 years |  |  |  |
Operating Lease | Vacant Property Little Rock, AR |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLittleRockArMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 672 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLittleRockArMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 77 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLittleRockArMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 44 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLittleRockArMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLittleRockArMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 672 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLittleRockArMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 121 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLittleRockArMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 793 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLittleRockArMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 35 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLittleRockArMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 20 years |  |  |  |
Operating Lease | Vacant Property Farmington, NM |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFarmingtonNMMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 2,757 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFarmingtonNMMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 0 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFarmingtonNMMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 730 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFarmingtonNMMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFarmingtonNMMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 2,757 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFarmingtonNMMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 730 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFarmingtonNMMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 3,487 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFarmingtonNMMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 121 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyFarmingtonNMMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property Bakersfield, CA |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBakersfieldCaMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 2,099 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBakersfieldCaMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 2,011 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBakersfieldCaMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 15 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBakersfieldCaMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBakersfieldCaMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 1,774 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBakersfieldCaMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 39 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBakersfieldCaMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,813 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBakersfieldCaMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 39 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBakersfieldCaMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Vacant Property Lubbock, TX 1 |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLubbockTx1Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 943 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLubbockTx1Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 957 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLubbockTx1Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLubbockTx1Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLubbockTx1Member |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 943 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLubbockTx1Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 957 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLubbockTx1Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,900 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLubbockTx1Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 197 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyLubbockTx1Member |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 20 years |  |  |  |
Operating Lease | Vacant Property Bristol, VA |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBristolVAMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 63 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBristolVAMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 184 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBristolVAMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBristolVAMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBristolVAMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 63 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBristolVAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 184 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBristolVAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 247 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBristolVAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 1 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VacantPropertyBristolVAMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 25 years |  |  |  |
Operating Lease | Value City Furniture White Marsh, MD |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_ValueCityFurnitureWhiteMarshMdMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 3,762 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_ValueCityFurnitureWhiteMarshMdMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 0 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_ValueCityFurnitureWhiteMarshMdMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 3,006 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_ValueCityFurnitureWhiteMarshMdMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_ValueCityFurnitureWhiteMarshMdMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 3,762 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_ValueCityFurnitureWhiteMarshMdMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 3,006 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_ValueCityFurnitureWhiteMarshMdMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 6,768 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_ValueCityFurnitureWhiteMarshMdMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 1,262 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_ValueCityFurnitureWhiteMarshMdMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | VCA Animal Hospital Mission, KS |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VcaAnimalHospitalMissionKsMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 891 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VcaAnimalHospitalMissionKsMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 3,758 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VcaAnimalHospitalMissionKsMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VcaAnimalHospitalMissionKsMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VcaAnimalHospitalMissionKsMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 852 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VcaAnimalHospitalMissionKsMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 3,758 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VcaAnimalHospitalMissionKsMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 4,610 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VcaAnimalHospitalMissionKsMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 350 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VcaAnimalHospitalMissionKsMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 30 years |  |  |  |
Operating Lease | Verizon Wireless Anderson, SC |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VerizonWirelessAndersonSCMember | [3] |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 38 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VerizonWirelessAndersonSCMember | [3] |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 0 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VerizonWirelessAndersonSCMember | [3] |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VerizonWirelessAndersonSCMember | [3] |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VerizonWirelessAndersonSCMember | [3] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 38 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VerizonWirelessAndersonSCMember | [1],[2],[3] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 0 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VerizonWirelessAndersonSCMember | [1],[2],[3] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 38 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VerizonWirelessAndersonSCMember | [1],[2],[3] |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 35 years | [3] |  |  |
Operating Lease | Verizon Wireless - Bristol, VA |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VerizonWirelessBristolVAMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 175 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VerizonWirelessBristolVAMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 512 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VerizonWirelessBristolVAMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VerizonWirelessBristolVAMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VerizonWirelessBristolVAMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 175 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VerizonWirelessBristolVAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 512 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VerizonWirelessBristolVAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 687 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VerizonWirelessBristolVAMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 12 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VerizonWirelessBristolVAMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 25 years |  |  |  |
Operating Lease | Virginia College Knoxville, TN |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VirginiaCollegeKnoxvilleTnMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 1,500 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VirginiaCollegeKnoxvilleTnMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 5,571 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VirginiaCollegeKnoxvilleTnMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VirginiaCollegeKnoxvilleTnMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VirginiaCollegeKnoxvilleTnMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 1,500 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VirginiaCollegeKnoxvilleTnMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 5,571 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VirginiaCollegeKnoxvilleTnMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 7,071 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VirginiaCollegeKnoxvilleTnMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 426 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VirginiaCollegeKnoxvilleTnMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 30 years |  |  |  |
Operating Lease | Vitamin Shoppe, The Cincinnati, OH |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VitaminShoppeCincinnatiOhMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 297 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VitaminShoppeCincinnatiOhMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 443 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VitaminShoppeCincinnatiOhMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 385 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VitaminShoppeCincinnatiOhMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VitaminShoppeCincinnatiOhMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 312 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VitaminShoppeCincinnatiOhMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 813 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VitaminShoppeCincinnatiOhMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,125 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VitaminShoppeCincinnatiOhMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 231 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VitaminShoppeCincinnatiOhMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Voodoo Skate Center Aransas Pass, TX |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VoodooSkateCenterAransasPassTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 90 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VoodooSkateCenterAransasPassTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 1,241 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VoodooSkateCenterAransasPassTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 137 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VoodooSkateCenterAransasPassTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VoodooSkateCenterAransasPassTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 89 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VoodooSkateCenterAransasPassTxMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 1,378 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VoodooSkateCenterAransasPassTxMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,467 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VoodooSkateCenterAransasPassTxMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 504 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_VoodooSkateCenterAransasPassTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Walgreens Sunrise, FL |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensSunriseFlMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 1,958 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensSunriseFlMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 1,401 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensSunriseFlMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensSunriseFlMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensSunriseFlMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 1,958 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensSunriseFlMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 1,401 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensSunriseFlMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 3,359 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensSunriseFlMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 407 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensSunriseFlMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Walgreens Tulsa, OK |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensTulsaOkMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 1,193 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensTulsaOkMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 3,056 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensTulsaOkMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensTulsaOkMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensTulsaOkMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 1,193 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensTulsaOkMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 3,056 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensTulsaOkMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 4,249 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensTulsaOkMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 729 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensTulsaOkMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Walgreens Boise, ID |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensBoiseIdMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 792 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensBoiseIdMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 1,875 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensBoiseIdMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensBoiseIdMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensBoiseIdMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 792 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensBoiseIdMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 1,875 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensBoiseIdMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 2,667 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensBoiseIdMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 300 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensBoiseIdMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 30 years |  |  |  |
Operating Lease | Walgreens Nampa, ID |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensNampaIdMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 1,062 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensNampaIdMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 2,253 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensNampaIdMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensNampaIdMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensNampaIdMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 1,062 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensNampaIdMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 2,253 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensNampaIdMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 3,315 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensNampaIdMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 360 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensNampaIdMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 30 years |  |  |  |
Operating Lease | Walgreens Pueblo, CO |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensPuebloCoMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 899 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensPuebloCoMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 3,313 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensPuebloCoMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensPuebloCoMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensPuebloCoMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 899 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensPuebloCoMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 3,313 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensPuebloCoMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 4,212 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensPuebloCoMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 336 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensPuebloCoMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 30 years |  |  |  |
Operating Lease | Walgreens Rapid City, SD |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensRapidCitySdMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 1,387 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensRapidCitySdMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 2,957 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensRapidCitySdMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensRapidCitySdMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensRapidCitySdMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 1,387 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensRapidCitySdMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 2,957 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensRapidCitySdMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 4,344 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensRapidCitySdMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 250 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensRapidCitySdMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 35 years |  |  |  |
Operating Lease | Walgreens Hamilton, OH |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensHamiltonOhMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 731 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensHamiltonOhMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 2,879 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensHamiltonOhMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensHamiltonOhMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensHamiltonOhMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 731 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensHamiltonOhMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 2,879 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensHamiltonOhMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 3,610 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensHamiltonOhMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 284 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WalgreensHamiltonOhMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 30 years |  |  |  |
Operating Lease | Waterford Nails and Spa Orlando, FL |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 19 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WaterfordNailsandSpaOrlandoFLMember | [4] |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 40 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WaterfordNailsandSpaOrlandoFLMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 111 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WaterfordNailsandSpaOrlandoFLMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WaterfordNailsandSpaOrlandoFLMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WaterfordNailsandSpaOrlandoFLMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 40 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WaterfordNailsandSpaOrlandoFLMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 111 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WaterfordNailsandSpaOrlandoFLMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 151 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WaterfordNailsandSpaOrlandoFLMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 30 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WaterfordNailsandSpaOrlandoFLMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Wawa Clearwater, FL |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WawaClearwaterFLMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 1,184 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WawaClearwaterFLMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 2,526 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WawaClearwaterFLMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 44 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WawaClearwaterFLMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WawaClearwaterFLMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 1,476 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WawaClearwaterFLMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,476 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WawaClearwaterFLMember | [1],[2] |  |  |
Operating Lease | Wehrenberg Theater Cedar Rapids, IA |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WehrenbergTheaterCedarRapidsIaMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 1,567 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WehrenbergTheaterCedarRapidsIaMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 8,433 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WehrenbergTheaterCedarRapidsIaMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WehrenbergTheaterCedarRapidsIaMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WehrenbergTheaterCedarRapidsIaMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 1,567 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WehrenbergTheaterCedarRapidsIaMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 8,433 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WehrenbergTheaterCedarRapidsIaMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 10,000 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WehrenbergTheaterCedarRapidsIaMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 729 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WehrenbergTheaterCedarRapidsIaMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Wendy's Sacramento, CA |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysSacramentoCaMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 586 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysSacramentoCaMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 0 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysSacramentoCaMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysSacramentoCaMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysSacramentoCaMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 586 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysSacramentoCaMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 586 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysSacramentoCaMember | [1],[2] |  |  |
Operating Lease | Wendy's New Kensington, PA |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysNewKensingtonPaMember | [3] |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 501 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysNewKensingtonPaMember | [3] |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 333 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysNewKensingtonPaMember | [3] |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysNewKensingtonPaMember | [3] |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysNewKensingtonPaMember | [3] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 501 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysNewKensingtonPaMember | [1],[2],[3] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 333 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysNewKensingtonPaMember | [1],[2],[3] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 834 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysNewKensingtonPaMember | [1],[2],[3] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 109 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysNewKensingtonPaMember | [3] |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years | [3] |  |  |
Operating Lease | Wendy's Orland Park, IL |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysOrlandParkIlMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 562 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysOrlandParkIlMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 556 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysOrlandParkIlMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysOrlandParkIlMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysOrlandParkIlMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 562 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysOrlandParkIlMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 377 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysOrlandParkIlMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 939 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysOrlandParkIlMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 125 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysOrlandParkIlMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 40 years |  |  |  |
Operating Lease | Wendy's Boerne, TX |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysBoerneTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 456 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysBoerneTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 679 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysBoerneTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysBoerneTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysBoerneTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 456 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysBoerneTxMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 679 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysBoerneTxMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,135 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysBoerneTxMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 55 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysBoerneTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 25 years |  |  |  |
Operating Lease | Wendy's Brownsburg, IN |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysBrownsburgInMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 242 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysBrownsburgInMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 1,483 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysBrownsburgInMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysBrownsburgInMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysBrownsburgInMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 242 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysBrownsburgInMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 1,483 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysBrownsburgInMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,725 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysBrownsburgInMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 121 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysBrownsburgInMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 25 years |  |  |  |
Operating Lease | Wendy's Converse, TX |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysConverseTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 301 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysConverseTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 554 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysConverseTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysConverseTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysConverseTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 301 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysConverseTxMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 554 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysConverseTxMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 855 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysConverseTxMember | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 32 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysConverseTxMember |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 35 years |  |  |  |
Operating Lease | Wendy's Everett, WA 1 |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysEverettWa1Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 486 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysEverettWa1Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 437 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysEverettWa1Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysEverettWa1Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysEverettWa1Member |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 486 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysEverettWa1Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 437 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysEverettWa1Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 923 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysEverettWa1Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 36 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysEverettWa1Member |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 25 years |  |  |  |
Operating Lease | Wendy's Everett, WA 2 |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysEverettWa2Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 339 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysEverettWa2Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 1,018 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysEverettWa2Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysEverettWa2Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysEverettWa2Member |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 339 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysEverettWa2Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 1,018 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysEverettWa2Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,357 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysEverettWa2Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 69 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysEverettWa2Member |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 30 years |  |  |  |
Operating Lease | Wendy's Fishers, IN 1 |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysFishersIn1Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 544 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysFishersIn1Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 514 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysFishersIn1Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysFishersIn1Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysFishersIn1Member |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 544 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysFishersIn1Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 514 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysFishersIn1Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,058 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysFishersIn1Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 35 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysFishersIn1Member |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 30 years |  |  |  |
Operating Lease | Wendy's Fishers, IN 2 |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysFishersIn2Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 766 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysFishersIn2Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 717 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysFishersIn2Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysFishersIn2Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysFishersIn2Member |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 766 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysFishersIn2Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 717 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysFishersIn2Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,483 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysFishersIn2Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 49 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysFishersIn2Member |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 30 years |  |  |  |
Operating Lease | Wendy's Henderson, NV 1 |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysHendersonNv1Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 398 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysHendersonNv1Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 1,028 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysHendersonNv1Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysHendersonNv1Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysHendersonNv1Member |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 398 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysHendersonNv1Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 1,028 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysHendersonNv1Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,426 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysHendersonNv1Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 70 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysHendersonNv1Member |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 30 years |  |  |  |
Operating Lease | Wendy's Henderson, NV 2 |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysHendersonNv2Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 370 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysHendersonNv2Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 311 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysHendersonNv2Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysHendersonNv2Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysHendersonNv2Member |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 370 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysHendersonNv2Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 311 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysHendersonNv2Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 681 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysHendersonNv2Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 25 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysHendersonNv2Member |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 25 years |  |  |  |
Operating Lease | Wendy's Indianapolis, IN 1 |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn1Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 281 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn1Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 1,018 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn1Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn1Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn1Member |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 281 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn1Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 1,018 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn1Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,299 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn1Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 69 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn1Member |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 30 years |  |  |  |
Operating Lease | Wendy's Indianapolis, IN 2 |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn2Member |  |  |  |
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Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 602 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn2Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn2Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn2Member |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 320 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn2Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 602 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn2Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 922 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn2Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | 41 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn2Member |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 30 years |  |  |  |
Operating Lease | Wendy's Indianapolis, IN 3 |  |  |  |  |
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items] |  |  |  |  |
Real Estate and Accumulated Depreciation, Encumbrances | 0 us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn3Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Land | 271 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn3Member |  |  |  |
Real Estate and Accumulated Depreciation, Initial Cost to Company, Building, Improvements & Leasehold Interests | 1,221 us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn3Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Improvements | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn3Member |  |  |  |
Real Estate and Accumulated Depreciation, Costs Capitalized Subsequent to Acquisition, Carrying Costs | 0 us-gaap_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisitionCarryingCosts / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn3Member |  |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land | 271 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn3Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Building, Improvements & Leasehold Interests | 1,221 us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn3Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Gross Amount at Which Carried at Close of Period, Land, Building, Improvements & Leasehold Interests | 1,492 us-gaap_RealEstateGrossAtCarryingValue / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn3Member | [1],[2] |  |  |
Real Estate and Accumulated Depreciation, Accumulated Depreciation and Amortization | $ 100 us-gaap_RealEstateAccumulatedDepreciation / nnn_ClassificationOfInvestmentPropertyLeasesByTypeOfLeaseAxis = nnn_OperatingLeaseMember / us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis = nnn_WendysIndianapolisIn3Member |  |  |  |
Real Estate and Accumulated Depreciation, Life on Which Depreciation & Amortization in Latest Income Statement is Computed | 25 years |  |  |  |
[1] | Transactions in real estate and accumulated depreciation during 2014, 2013, and 2012 are summarized as follows: 2014 2013 2012Land, buildings, and leasehold interests: Balance at the beginning of year$4,686,844 $4,145,368 $3,531,845Acquisitions, completed construction and tenant improvements601,168 602,836 701,054Disposition of land, buildings, and leasehold interests(50,938) (57,254) (77,219)Provision for loss on impairment of real estate(823) (4,106) (10,312)Balance at the close of year$5,236,251 $4,686,844 $4,145,368Accumulated depreciation and amortization: Balance at the beginning of year$418,136 $333,778 $270,621Disposition of land, buildings, and leasehold interests(9,153) (6,778) (6,980)Depreciation and amortization expense104,192 91,136 70,137Balance at the close of year$513,175 $418,136 $333,778
[2] | As of December 31, 2014, the leases are treated as either operating or financing leases for federal income tax purposes. As of December 31, 2014, the aggregate cost of the properties owned by NNN that are under operating leases were $5,119,673 and financing leases were $2,703.
[3] | The tenant of this property has subleased the property. The tenant continues to be responsible for complying with all the terms of the lease agreement and is continuing to pay rent on this property to NNN.
[4] | Property is encumbered as a part of NNN's $6,952 long-term, fixed rate mortgage and security agreement.

X
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