Revenue Recognition (Revenue by Segment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Lease revenues	$ 1,543,317	$ 1,373,691	$ 1,343,391
Operating Lease, Lease Income, Statement of Income or Comprehensive Income [Extensible Enumeration]	Total revenues
Total revenues	$ 1,799,995	1,589,210	1,527,951
Rental revenues
Disaggregation of Revenue [Line Items]
Total revenues	1,607,685	1,424,531	1,377,635
Lease Revenues
Disaggregation of Revenue [Line Items]
Lease revenues	1,543,317	1,373,691	1,343,391
Property rentals
Disaggregation of Revenue [Line Items]
Lease revenues	1,510,648	1,354,209	1,323,347
Hotel Pennsylvania site
Disaggregation of Revenue [Line Items]
Lease revenues			8,741
Trade shows
Disaggregation of Revenue [Line Items]
Lease revenues	32,669	19,482	11,303
Tenant services
Disaggregation of Revenue [Line Items]
Revenues	45,211	37,449	34,244
Parking revenues
Disaggregation of Revenue [Line Items]
Revenues	19,157	13,391
Fee and other income
Disaggregation of Revenue [Line Items]
Revenues	192,310	164,679	150,316
Total revenues	192,310	164,679	150,316
BMS cleaning fees
Disaggregation of Revenue [Line Items]
Revenues	137,673	119,780	105,536
Management and leasing fees
Disaggregation of Revenue [Line Items]
Revenues	11,039	11,725	19,416
Other income
Disaggregation of Revenue [Line Items]
Revenues	43,598	33,174	25,364
New York
Disaggregation of Revenue [Line Items]
Total revenues	1,449,442	1,257,599	1,221,748
New York | Rental revenues
Disaggregation of Revenue [Line Items]
Total revenues	1,280,181	1,109,234	1,083,500
New York | Lease Revenues
Disaggregation of Revenue [Line Items]
Lease revenues	1,230,851	1,071,816	1,059,750
New York | Property rentals
Disaggregation of Revenue [Line Items]
Lease revenues	1,230,851	1,071,816	1,051,009
New York | Hotel Pennsylvania site
Disaggregation of Revenue [Line Items]
Lease revenues			8,741
New York | Trade shows
Disaggregation of Revenue [Line Items]
Lease revenues	0	0	0
New York | Tenant services
Disaggregation of Revenue [Line Items]
Revenues	33,351	26,048	23,750
New York | Parking revenues
Disaggregation of Revenue [Line Items]
Revenues	15,979	11,370
New York | Fee and other income
Disaggregation of Revenue [Line Items]
Revenues	169,261	148,365	138,248
New York | BMS cleaning fees
Disaggregation of Revenue [Line Items]
Revenues	146,530	126,891	112,112
New York | Management and leasing fees
Disaggregation of Revenue [Line Items]
Revenues	11,645	12,177	19,508
New York | Other income
Disaggregation of Revenue [Line Items]
Revenues	11,086	9,297	6,628
Other
Disaggregation of Revenue [Line Items]
Total revenues	350,553	331,611	306,203
Other | Rental revenues
Disaggregation of Revenue [Line Items]
Total revenues	327,504	315,297	294,135
Other | Lease Revenues
Disaggregation of Revenue [Line Items]
Lease revenues	312,466	301,875	283,641
Other | Property rentals
Disaggregation of Revenue [Line Items]
Lease revenues	279,797	282,393	272,338
Other | Hotel Pennsylvania site
Disaggregation of Revenue [Line Items]
Lease revenues			0
Other | Trade shows
Disaggregation of Revenue [Line Items]
Lease revenues	32,669	19,482	11,303
Other | Tenant services
Disaggregation of Revenue [Line Items]
Revenues	11,860	11,401	10,494
Other | Parking revenues
Disaggregation of Revenue [Line Items]
Revenues	3,178	2,021
Other | Fee and other income
Disaggregation of Revenue [Line Items]
Revenues	23,049	16,314	12,068
Other | BMS cleaning fees
Disaggregation of Revenue [Line Items]
Revenues	(8,857)	(7,111)	(6,576)
Other | Management and leasing fees
Disaggregation of Revenue [Line Items]
Revenues	(606)	(452)	(92)
Other | Other income
Disaggregation of Revenue [Line Items]
Revenues	$ 32,512	$ 23,877	$ 18,736