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Basis of Presentation - Additional Information (Detail) $ in Thousands | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2018 USD ($) | Sep. 30, 2019 USD ($) segment | Sep. 30, 2018 USD ($) | Dec. 31, 2018 USD ($)
Error Corrections and Prior Period Adjustments Restatement [Line Items] |  |  |  |
Mortgages payable, net of deferred debt issuance costs |  | $ (969,673) |  | $ (965,826)
Number of reportable segments | segment |  | 1 |  |
Previously Reported |  |  |  |
Error Corrections and Prior Period Adjustments Restatement [Line Items] |  |  |  |
Loan participation balance |  |  |  | 195,708
Restatement Adjustment |  |  |  |
Error Corrections and Prior Period Adjustments Restatement [Line Items] |  |  |  |
Property rentals | $ 38,250 |  | $ 115,109 |
Expense reimbursements | $ 20,875 |  | $ 60,149 |
Restatement to reclassify Rego Park II as a reduction to mortgage payable, net of deferred debt issuance costs | Restatement Adjustment |  |  |  |
Error Corrections and Prior Period Adjustments Restatement [Line Items] |  |  |  |
Mortgages payable, net of deferred debt issuance costs |  |  |  | $ 195,708

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