Revenue Recognition (Summary of Revenues by Segment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Operating Lease, Lease Income, Statement of Income or Comprehensive Income [Extensible Enumeration]	Total revenues
Lease revenues	$ 1,544,671	$ 1,543,317	$ 1,373,691
Total revenues	1,811,163	1,799,995	1,589,210
Loss contingency, damages awarded, value	21,350
Non- controlling Interests in Consolidated Subsidiaries
Disaggregation of Revenue [Line Items]
Loss contingency, damages awarded, value	6,405
Rental revenues
Disaggregation of Revenue [Line Items]
Total revenues	1,607,486	1,607,685	1,424,531
Lease Revenues
Disaggregation of Revenue [Line Items]
Lease revenues	1,544,671	1,543,317	1,373,691
Property rentals
Disaggregation of Revenue [Line Items]
Lease revenues	1,523,890	1,510,648	1,354,209
Trade shows
Disaggregation of Revenue [Line Items]
Lease revenues	20,781	32,669	19,482
Tenant services
Disaggregation of Revenue [Line Items]
Revenues	42,460	45,211	37,449
Parking revenues
Disaggregation of Revenue [Line Items]
Revenues	20,355	19,157	13,391
Fee and other income
Disaggregation of Revenue [Line Items]
Revenues	203,677	192,310	164,679
Total revenues	203,677	192,310	164,679
BMS cleaning fees
Disaggregation of Revenue [Line Items]
Revenues	141,937	137,673	119,780
Management and leasing fees
Disaggregation of Revenue [Line Items]
Revenues	13,040	11,039	11,725
Other income
Disaggregation of Revenue [Line Items]
Revenues	48,700	43,598	33,174
New York
Disaggregation of Revenue [Line Items]
Total revenues	1,452,158	1,449,442	1,257,599
New York | Rental revenues
Disaggregation of Revenue [Line Items]
Total revenues	1,269,817	1,280,181	1,109,234
New York | Lease Revenues
Disaggregation of Revenue [Line Items]
Lease revenues	1,222,229	1,230,851	1,071,816
New York | Property rentals
Disaggregation of Revenue [Line Items]
Lease revenues	1,222,229	1,230,851	1,071,816
New York | Trade shows
Disaggregation of Revenue [Line Items]
Lease revenues	0	0	0
New York | Tenant services
Disaggregation of Revenue [Line Items]
Revenues	31,086	33,351	26,048
New York | Parking revenues
Disaggregation of Revenue [Line Items]
Revenues	16,502	15,979	11,370
New York | Fee and other income
Disaggregation of Revenue [Line Items]
Revenues	182,341	169,261	148,365
New York | BMS cleaning fees
Disaggregation of Revenue [Line Items]
Revenues	151,608	146,530	126,891
New York | Management and leasing fees
Disaggregation of Revenue [Line Items]
Revenues	13,619	11,645	12,177
New York | Other income
Disaggregation of Revenue [Line Items]
Revenues	17,114	11,086	9,297
Other
Disaggregation of Revenue [Line Items]
Total revenues	359,005	350,553	331,611
Other | Rental revenues
Disaggregation of Revenue [Line Items]
Total revenues	337,669	327,504	315,297
Other | Lease Revenues
Disaggregation of Revenue [Line Items]
Lease revenues	322,442	312,466	301,875
Other | Property rentals
Disaggregation of Revenue [Line Items]
Lease revenues	301,661	279,797	282,393
Other | Trade shows
Disaggregation of Revenue [Line Items]
Lease revenues	20,781	32,669	19,482
Other | Tenant services
Disaggregation of Revenue [Line Items]
Revenues	11,374	11,860	11,401
Other | Parking revenues
Disaggregation of Revenue [Line Items]
Revenues	3,853	3,178	2,021
Other | Fee and other income
Disaggregation of Revenue [Line Items]
Revenues	21,336	23,049	16,314
Other | BMS cleaning fees
Disaggregation of Revenue [Line Items]
Revenues	(9,671)	(8,857)	(7,111)
Other | Management and leasing fees
Disaggregation of Revenue [Line Items]
Revenues	(579)	(606)	(452)
Other | Other income
Disaggregation of Revenue [Line Items]
Revenues	$ 31,586	$ 32,512	$ 23,877