Revenue Recognition (Revenues by Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Disaggregation of Revenue [Line Items]
Lease income	$ 388,891	$ 330,944	$ 771,922	$ 663,002
Total revenues	453,494	378,941	895,624	758,918
New York
Disaggregation of Revenue [Line Items]
Total revenues	364,162	301,144	722,710	605,115
Other
Disaggregation of Revenue [Line Items]
Total revenues	89,332	77,797	172,914	153,803
Rental revenues
Disaggregation of Revenue [Line Items]
Total revenues	405,194	339,596	802,477	678,913
Rental revenues | New York
Disaggregation of Revenue [Line Items]
Total revenues	322,040	266,881	640,885	533,581
Rental revenues | Other
Disaggregation of Revenue [Line Items]
Total revenues	83,154	72,715	161,592	145,332
Lease revenues
Disaggregation of Revenue [Line Items]
Lease income	388,891	330,944	771,922	663,002
Lease revenues | New York
Disaggregation of Revenue [Line Items]
Lease income	309,882	260,953	617,605	522,644
Lease revenues | Other
Disaggregation of Revenue [Line Items]
Lease income	79,009	69,991	154,317	140,358
Property rentals
Disaggregation of Revenue [Line Items]
Lease income	383,049	330,944	760,936	663,002
Property rentals | New York
Disaggregation of Revenue [Line Items]
Lease income	309,882	260,953	617,605	522,644
Property rentals | Other
Disaggregation of Revenue [Line Items]
Lease income	73,167	69,991	143,331	140,358
Trade shows
Disaggregation of Revenue [Line Items]
Lease income	5,842	0	10,986	0
Trade shows | New York
Disaggregation of Revenue [Line Items]
Lease income	0	0	0	0
Trade shows | Other
Disaggregation of Revenue [Line Items]
Lease income	5,842	0	10,986	0
Tenant services
Disaggregation of Revenue [Line Items]
Revenue	11,461	8,652	21,350	15,911
Tenant services | New York
Disaggregation of Revenue [Line Items]
Revenue	8,133	5,928	15,544	10,937
Tenant services | Other
Disaggregation of Revenue [Line Items]
Revenue	3,328	2,724	5,806	4,974
Parking revenues
Disaggregation of Revenue [Line Items]
Revenue	4,842	0	9,205	0
Parking revenues | New York
Disaggregation of Revenue [Line Items]
Revenue	4,025	0	7,736	0
Parking revenues | Other
Disaggregation of Revenue [Line Items]
Revenue	817	0	1,469	0
Fee and other income
Disaggregation of Revenue [Line Items]
Revenue	48,300	39,345	93,147	80,005
Total revenues	48,300	39,345	93,147	80,005
Fee and other income | New York
Disaggregation of Revenue [Line Items]
Revenue	42,122	34,263	81,825	71,534
Fee and other income | Other
Disaggregation of Revenue [Line Items]
Revenue	6,178	5,082	11,322	8,471
BMS cleaning fees
Disaggregation of Revenue [Line Items]
Revenue	33,999	28,083	66,690	56,560
BMS cleaning fees | New York
Disaggregation of Revenue [Line Items]
Revenue	36,206	29,600	70,917	59,548
BMS cleaning fees | Other
Disaggregation of Revenue [Line Items]
Revenue	(2,207)	(1,517)	(4,227)	(2,988)
Management and leasing fees
Disaggregation of Revenue [Line Items]
Revenue	2,866	3,073	5,635	8,442
Management and leasing fees | New York
Disaggregation of Revenue [Line Items]
Revenue	3,011	3,088	5,978	8,610
Management and leasing fees | Other
Disaggregation of Revenue [Line Items]
Revenue	(145)	(15)	(343)	(168)
Other income
Disaggregation of Revenue [Line Items]
Revenue	11,435	8,189	20,822	15,003
Other income | New York
Disaggregation of Revenue [Line Items]
Revenue	2,905	1,575	4,930	3,376
Other income | Other
Disaggregation of Revenue [Line Items]
Revenue	$ 8,530	$ 6,614	$ 15,892	$ 11,627