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Mortgages Payable - Additional Information (Detail) - USD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2021 | Dec. 31, 2020
Mortgage Loans on Real Estate |  |
Net carrying value of real estate collateralizing the debt | $ 629,134 |
Mortgages payable, net of deferred debt issuance costs | 1,089,613 | $ 1,156,170
Mortgages |  |
Mortgage Loans on Real Estate |  |
Mortgages payable, net of deferred debt issuance costs | $ 1,089,613 | $ 1,156,170
731 Lexington Avenue | Office space | Mortgages |  |
Mortgage Loans on Real Estate |  |
Debt instrument, description of variable rate basis | LIBOR |
Interest rate | 0.0101% |
731 Lexington Avenue | Office space | Mortgages | LIBOR |  |
Mortgage Loans on Real Estate |  |
Basis spread over LIBOR | 0.90% |
731 Lexington Avenue | Retail space | Mortgages |  |
Mortgage Loans on Real Estate |  |
Interest rate | 0.0172% |
731 Lexington Avenue | Retail space | Mortgages | Interest rate swap |  |
Mortgage Loans on Real Estate |  |
Debt instrument, description of variable rate basis | LIBOR |
Interest rate | 1.72% |
731 Lexington Avenue | Retail space | Mortgages | LIBOR | Interest rate swap |  |
Mortgage Loans on Real Estate |  |
Basis spread over LIBOR | 1.40% |
Rego Park II | Retail space | Mortgages |  |
Mortgage Loans on Real Estate |  |
Debt instrument, description of variable rate basis | LIBOR |
Interest rate | 0.0145% |
Rego Park II | Retail space | Mortgages | LIBOR |  |
Mortgage Loans on Real Estate |  |
Basis spread over LIBOR | 1.35% |

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