Segments - Schedule of NOI for Each Reportable Segment Information (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Segment Reporting Information [Line Items]
Property-related revenues		$ 182,015	$ 172,570	$ 533,255	$ 523,134
Property-related operating expenses		(72,845)	(67,131)	(207,320)	(197,821)
NOI from unconsolidated joint ventures (excluding One Steuart Lane)		11,540	11,627	34,359	32,510
NOI	[1]	120,710	117,066	360,294	357,823
New York [Member]
Segment Reporting Information [Line Items]
Property-related revenues		117,431	109,842	349,136	329,870
Property-related operating expenses		(52,421)	(47,545)	(148,779)	(142,370)
NOI from unconsolidated joint ventures (excluding One Steuart Lane)		3,556	2,875	9,902	8,445
NOI	[1]	68,566	65,172	210,259	195,945
San Francisco [Member]
Segment Reporting Information [Line Items]
Property-related revenues		64,667	63,527	185,798	195,673
Property-related operating expenses		(19,496)	(18,646)	(55,369)	(52,651)
NOI from unconsolidated joint ventures (excluding One Steuart Lane)		7,837	8,665	24,162	24,054
NOI	[1]	53,008	53,546	154,591	167,076
Other [Member]
Segment Reporting Information [Line Items]
Property-related revenues		(83)	(799)	(1,679)	(2,409)
Property-related operating expenses		(928)	(940)	(3,172)	(2,800)
NOI from unconsolidated joint ventures (excluding One Steuart Lane)		147	87	295	11
NOI	[1]	$ (864)	$ (1,652)	$ (4,556)	$ (5,198)

[1] NOI is used to measure the operating performance of our properties. NOI consists of rental revenue (which includes property rentals, tenant reimbursements and lease termination income) and certain other property-related revenue less operating expenses (which includes property-related expenses such as cleaning, security, repairs and maintenance, utilities, property administration and real estate taxes). We use NOI internally as a performance measure and believe it provides useful information to investors regarding our financial condition and results of operations because it reflects only those income and expense items that are incurred at the property level. Other real estate companies may use different methodologies for calculating NOI and, accordingly, our presentation of NOI may not be comparable to other real estate companies.