Related Party Transactions - Summary of Fees to Vornado (Detail) - Vornado - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Related Party Transaction [Line Items]
Fees to related party	$ 1,970	$ 4,019	$ 4,172	$ 6,619
Company management fees
Related Party Transaction [Line Items]
Fees to related party	700	700	1,400	1,400
Development fees
Related Party Transaction [Line Items]
Fees to related party	122	5	268	29
Leasing fees
Related Party Transaction [Line Items]
Fees to related party	9	2,017	59	2,746
Property management, cleaning, engineering and security fees
Related Party Transaction [Line Items]
Fees to related party	$ 1,139	$ 1,297	$ 2,445	$ 2,444