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Mortgages Payable - Summary of Outstanding Mortgages Payable (Detail) - USD ($) $ in Thousands | 9 Months Ended |
--- | --- | ---
Sep. 30, 2021 | Dec. 31, 2020
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items] |  |
Notes payable | $ 1,157,263 | $ 1,156,170
Mortgages |  |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items] |  |
Mortgage payable gross | 1,164,544 | 1,164,544
Deferred debt issuance costs, net of accumulated amortization of $14,172 and $13,034, respectively | (7,281) | (8,374)
Notes payable | 1,157,263 | 1,156,170
Deferred debt issuance costs, accumulated amortization | $ 14,172 | 13,034
Mortgages | Paramus |  |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items] |  |
Maturity date | Oct. 04, 2021 |
Interest rate (in percentage) | 4.72% |
Mortgage payable gross | $ 68,000 | 68,000
Mortgages | 731 Lexington Avenue | Office Space |  |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items] |  |
Maturity date | Jun. 11, 2024 |
Interest rate (in percentage) | 0.98% |
Mortgage payable gross | $ 500,000 | 500,000
Mortgages | 731 Lexington Avenue | Retail Space |  |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items] |  |
Maturity date | Aug. 05, 2025 |
Interest rate (in percentage) | 1.72% |
Mortgage payable gross | $ 300,000 | 300,000
Mortgages | Rego Park II | Retail Space |  |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items] |  |
Maturity date | Dec. 12, 2025 |
Interest rate (in percentage) | 1.43% |
Mortgage payable gross | $ 202,544 | 202,544
Mortgages | Alexander Apartment Tower | Apartment Building |  |
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items] |  |
Maturity date | Nov. 01, 2027 |
Interest rate (in percentage) | 2.63% |
Mortgage payable gross | $ 94,000 | $ 94,000

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