Revenue Recognition (Revenue by Segment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Lease revenues	$ 1,373,691	$ 1,343,391	$ 1,719,710
Total revenues	1,589,210	1,527,951	1,924,700
Write-off of lease receivables deemed uncollectible	7,695	63,204	17,237
Rental revenues
Disaggregation of Revenue [Line Items]
Total revenues	1,424,531	1,377,635	1,767,222
Lease Revenues
Disaggregation of Revenue [Line Items]
Lease revenues	1,373,691	1,343,391	1,719,710
Property rentals
Disaggregation of Revenue [Line Items]
Lease revenues	1,354,209	1,323,347	1,589,539
Write-off of lease receivables deemed uncollectible		63,204	17,237
Hotel Pennsylvania
Disaggregation of Revenue [Line Items]
Lease revenues		8,741	89,594
Parking Revenue
Disaggregation of Revenue [Line Items]
Revenues	13,391
Trade shows
Disaggregation of Revenue [Line Items]
Lease revenues	19,482	11,303	40,577
Tenant services
Disaggregation of Revenue [Line Items]
Revenues	37,449	34,244	47,512
Fee and other income
Disaggregation of Revenue [Line Items]
Revenues	164,679	150,316	157,478
Total revenues	164,679	150,316	157,478
BMS cleaning fees
Disaggregation of Revenue [Line Items]
Revenues	119,780	105,536	124,674
Management and leasing fees
Disaggregation of Revenue [Line Items]
Revenues	11,725	19,416	13,542
Other income
Disaggregation of Revenue [Line Items]
Revenues	33,174	25,364	19,262
New York
Disaggregation of Revenue [Line Items]
Total revenues	1,257,599	1,221,748	1,577,860
New York | Rental revenues
Disaggregation of Revenue [Line Items]
Total revenues	1,109,234	1,083,500	1,424,990
New York | Lease Revenues
Disaggregation of Revenue [Line Items]
Lease revenues	1,071,816	1,059,750	1,389,979
New York | Property rentals
Disaggregation of Revenue [Line Items]
Lease revenues	1,071,816	1,051,009	1,300,385
New York | Hotel Pennsylvania
Disaggregation of Revenue [Line Items]
Lease revenues		8,741	89,594
New York | Parking Revenue
Disaggregation of Revenue [Line Items]
Revenues	11,370
New York | Trade shows
Disaggregation of Revenue [Line Items]
Lease revenues	0	0	0
New York | Tenant services
Disaggregation of Revenue [Line Items]
Revenues	26,048	23,750	35,011
New York | Fee and other income
Disaggregation of Revenue [Line Items]
Revenues	148,365	138,248	152,870
New York | BMS cleaning fees
Disaggregation of Revenue [Line Items]
Revenues	126,891	112,112	133,358
New York | Management and leasing fees
Disaggregation of Revenue [Line Items]
Revenues	12,177	19,508	13,694
New York | Other income
Disaggregation of Revenue [Line Items]
Revenues	9,297	6,628	5,818
Other
Disaggregation of Revenue [Line Items]
Total revenues	331,611	306,203	346,840
Other | Rental revenues
Disaggregation of Revenue [Line Items]
Total revenues	315,297	294,135	342,232
Other | Lease Revenues
Disaggregation of Revenue [Line Items]
Lease revenues	301,875	283,641	329,731
Other | Property rentals
Disaggregation of Revenue [Line Items]
Lease revenues	282,393	272,338	289,154
Other | Hotel Pennsylvania
Disaggregation of Revenue [Line Items]
Lease revenues		0	0
Other | Parking Revenue
Disaggregation of Revenue [Line Items]
Revenues	2,021
Other | Trade shows
Disaggregation of Revenue [Line Items]
Lease revenues	19,482	11,303	40,577
Other | Tenant services
Disaggregation of Revenue [Line Items]
Revenues	11,401	10,494	12,501
Other | Fee and other income
Disaggregation of Revenue [Line Items]
Revenues	16,314	12,068	4,608
Other | BMS cleaning fees
Disaggregation of Revenue [Line Items]
Revenues	(7,111)	(6,576)	(8,684)
Other | Management and leasing fees
Disaggregation of Revenue [Line Items]
Revenues	(452)	(92)	(152)
Other | Other income
Disaggregation of Revenue [Line Items]
Revenues	$ 23,877	$ 18,736	$ 13,444