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Commitments and Contingencies (Litigation and contingencies) (Details) ft² in Thousands, $ in Thousands | 1 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | ---
Oct. 31, 2021 USD ($) | Mar. 31, 2016 USD ($) | Feb. 28, 2014 fire | Dec. 31, 2020 USD ($) ft² | Dec. 31, 2019 USD ($) | Dec. 31, 2001 a
Commitments And Contingencies Disclosure |  |  |  |  |  |
Mortgages payable, carrying value |  |  |  | $ 1,156,170 | $ 970,961 |
Standby letters of credit, outstanding |  |  |  | 960 |  |
Paramus, NJ | IKEA | Tenant Occupant |  |  |  |  |  |
Commitments And Contingencies Disclosure |  |  |  |  |  |
Area of land | a |  |  |  |  |  | 30.3
Mortgages payable, carrying value |  |  |  | $ 68,000 |  |
Debt instrument, interest rate, stated percentage |  |  |  | 4.72% |  |
Maturity date |  |  |  | Oct. 04, 2021 |  |
Triple-net rent, annual amount |  |  |  | $ 700 |  |
Paramus, NJ | IKEA | Forecast | Tenant Occupant |  |  |  |  |  |
Commitments And Contingencies Disclosure |  |  |  |  |  |
Property purchase option exercisable by lessee | $ 75,000 |  |  |  |  |
Purchase option exercised, net cash proceeds from sale of land | 7,000 |  |  |  |  |
Gain (loss) on disposition of real estate, discontinued operations | $ 60,000 |  |  |  |  |
Lease term range as Lessor | 20 years |  |  |  |  |
Purchase option not exercised amount included in triple net rent over remainder of lease | $ 68,000 |  |  |  |  |
Loan amortization period | 20 years |  |  |  |  |
Rego Park I | Sears |  |  |  |  |  |
Commitments And Contingencies Disclosure |  |  |  |  |  |
Area of land | ft² |  |  |  | 195 |  |
Number of fires | fire |  |  | 2 |  |  |
Minimum | Rego Park I | Sears |  |  |  |  |  |
Commitments And Contingencies Disclosure |  |  |  |  |  |
Loss contingency, damages sought, value |  |  |  | $ 4,000 |  |
Estimated Future Damages | Rego Park I | Sears |  |  |  |  |  |
Commitments And Contingencies Disclosure |  |  |  |  |  |
Loss contingency, damages sought, value |  | $ 650 |  |  |  |
Estimated Future Damages | Minimum | Rego Park I | Sears |  |  |  |  |  |
Commitments And Contingencies Disclosure |  |  |  |  |  |
Loss contingency, damages sought, value |  |  |  | 25,000 |  |
Estimated Future Damages | Maximum | Rego Park I | Sears |  |  |  |  |  |
Commitments And Contingencies Disclosure |  |  |  |  |  |
Loss contingency, estimate of possible loss |  |  |  | $ 650 |  |

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