Segments - Schedule of NOI for Each Reportable Segment Information (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Segment Reporting Information [Line Items]
Property-related revenues		$ 179,543	$ 176,068	$ 351,240	$ 350,564
Property-related operating expenses		(67,814)	(64,072)	(134,475)	(130,690)
NOI from unconsolidated joint ventures (excluding One Steuart Lane)		11,585	10,557	22,819	20,883
NOI	[1]	123,314	122,553	239,584	240,757
New York [Member]
Segment Reporting Information [Line Items]
Property-related revenues		116,300	108,191	231,705	220,028
Property-related operating expenses		(48,147)	(45,801)	(96,358)	(94,825)
NOI from unconsolidated joint ventures (excluding One Steuart Lane)		3,528	2,749	6,346	5,570
NOI	[1]	71,681	65,139	141,693	130,773
San Francisco [Member]
Segment Reporting Information [Line Items]
Property-related revenues		64,042	68,674	121,131	132,146
Property-related operating expenses		(18,581)	(17,067)	(35,873)	(34,005)
NOI from unconsolidated joint ventures (excluding One Steuart Lane)		7,971	7,852	16,325	15,389
NOI	[1]	53,432	59,459	101,583	113,530
Other [Member]
Segment Reporting Information [Line Items]
Property-related revenues		(799)	(797)	(1,596)	(1,610)
Property-related operating expenses		(1,086)	(1,204)	(2,244)	(1,860)
NOI from unconsolidated joint ventures (excluding One Steuart Lane)		86	(44)	148	(76)
NOI	[1]	$ (1,799)	$ (2,045)	$ (3,692)	$ (3,546)

[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.