Segments - Schedule of NOI for Each Reportable Segment Information (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Segment Reporting Information [Line Items]
Property-related revenues		$ 184,608	$ 182,015	$ 536,211	$ 533,255
Property-related operating expenses		(75,502)	(72,845)	(216,889)	(207,320)
NOI from unconsolidated joint ventures (excluding One Steuart Lane)		9,233	11,540	30,334	34,359
NOI	[1]	118,339	120,710	349,656	360,294
New York [Member]
Segment Reporting Information [Line Items]
Property-related revenues		118,749	117,431	342,812	349,136
Property-related operating expenses		(52,470)	(52,421)	(150,676)	(148,779)
NOI from unconsolidated joint ventures (excluding One Steuart Lane)		3,376	3,556	10,143	9,902
NOI	[1]	69,655	68,566	202,279	210,259
San Francisco [Member]
Segment Reporting Information [Line Items]
Property-related revenues		66,252	64,667	194,564	185,798
Property-related operating expenses		(22,447)	(19,496)	(64,529)	(55,369)
NOI from unconsolidated joint ventures (excluding One Steuart Lane)		5,858	7,837	20,133	24,162
NOI	[1]	49,663	53,008	150,168	154,591
Other [Member]
Segment Reporting Information [Line Items]
Property-related revenues		(393)	(83)	(1,165)	(1,679)
Property-related operating expenses		(585)	(928)	(1,684)	(3,172)
NOI from unconsolidated joint ventures (excluding One Steuart Lane)		(1)	147	58	295
NOI	[1]	$ (979)	$ (864)	$ (2,791)	$ (4,556)

[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.