Related Party Transactions - Summary of Fees to Vornado (Detail) - Vornado - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Related Party Transaction [Line Items]
Fees to related party	$ 2,565	$ 1,733
Company management fees
Related Party Transaction [Line Items]
Fees to related party	657	700
Development fees
Related Party Transaction [Line Items]
Fees to related party	24	7
Leasing fees
Related Party Transaction [Line Items]
Fees to related party	737	0
Property management, cleaning, engineering and security fees
Related Party Transaction [Line Items]
Fees to related party	$ 1,147	$ 1,026