Investments in Unconsolidated Joint Ventures - Summary of Investments and Income from Investments In Unconsolidated Joint Ventures (Parenthetical) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020 USD ($)
712 Fifth Avenue [Member]
Schedule Of Equity Method Investments [Line Items]
Distributions made in excess of share of earnings recognized negative basis	$ 21,454
55 Second Street [Member]
Schedule Of Equity Method Investments [Line Items]
Difference between carrying amount of investment and equity	490
60 Wall Street [Member]
Schedule Of Equity Method Investments [Line Items]
Difference between carrying amount of investment and equity	2,677
One Steuart Lane [Member]
Schedule Of Equity Method Investments [Line Items]
Difference between carrying amount of investment and equity	970
Oder-Center, Germany [Member]
Schedule Of Equity Method Investments [Line Items]
Difference between carrying amount of investment and equity	$ 4,652