Revenue Recognition (Revenues by Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Disaggregation of Revenue [Line Items]
Lease income	$ 390,408	$ 357,840	$ 1,162,330	$ 1,020,842
Total revenues	457,431	409,212	1,353,055	1,168,130
New York
Disaggregation of Revenue [Line Items]
Total revenues	360,033	316,643	1,082,743	921,758
Other
Disaggregation of Revenue [Line Items]
Total revenues	97,398	92,569	270,312	246,372
Rental revenues
Disaggregation of Revenue [Line Items]
Total revenues	409,144	369,203	1,211,621	1,048,116
Rental revenues | New York
Disaggregation of Revenue [Line Items]
Total revenues	317,331	280,762	958,216	814,343
Rental revenues | Other
Disaggregation of Revenue [Line Items]
Total revenues	91,813	88,441	253,405	233,773
Lease revenues
Disaggregation of Revenue [Line Items]
Lease income	390,408	357,840	1,162,330	1,020,842
Lease revenues | New York
Disaggregation of Revenue [Line Items]
Lease income	303,574	273,197	921,179	795,841
Lease revenues | Other
Disaggregation of Revenue [Line Items]
Lease income	86,834	84,643	241,151	225,001
Property rentals
Disaggregation of Revenue [Line Items]
Lease income	371,754	345,235	1,132,690	1,008,237
Property rentals | New York
Disaggregation of Revenue [Line Items]
Lease income	303,574	273,197	921,179	795,841
Property rentals | Other
Disaggregation of Revenue [Line Items]
Lease income	68,180	72,038	211,511	212,396
Trade shows
Disaggregation of Revenue [Line Items]
Lease income	18,654	12,605	29,640	12,605
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	18,654	12,605	29,640	12,605
Tenant services
Disaggregation of Revenue [Line Items]
Revenue	14,134	11,363	35,484	27,274
Tenant services | New York
Disaggregation of Revenue [Line Items]
Revenue	9,937	7,565	25,481	18,502
Tenant services | Other
Disaggregation of Revenue [Line Items]
Revenue	4,197	3,798	10,003	8,772
Parking revenues
Disaggregation of Revenue [Line Items]
Revenue	4,602	0	13,807	0
Parking revenues | New York
Disaggregation of Revenue [Line Items]
Revenue	3,820	0	11,556	0
Parking revenues | Other
Disaggregation of Revenue [Line Items]
Revenue	782	0	2,251	0
Fee and other income
Disaggregation of Revenue [Line Items]
Revenue	48,287	40,009	141,434	120,014
Total revenues	48,287	40,009	141,434	120,014
Fee and other income | New York
Disaggregation of Revenue [Line Items]
Revenue	42,702	35,881	124,527	107,415
Fee and other income | Other
Disaggregation of Revenue [Line Items]
Revenue	5,585	4,128	16,907	12,599
BMS cleaning fees
Disaggregation of Revenue [Line Items]
Revenue	35,062	30,827	101,752	87,387
BMS cleaning fees | New York
Disaggregation of Revenue [Line Items]
Revenue	37,371	32,630	108,288	92,178
BMS cleaning fees | Other
Disaggregation of Revenue [Line Items]
Revenue	(2,309)	(1,803)	(6,536)	(4,791)
Management and leasing fees
Disaggregation of Revenue [Line Items]
Revenue	2,532	2,509	8,167	10,951
Management and leasing fees | New York
Disaggregation of Revenue [Line Items]
Revenue	2,595	2,680	8,573	11,290
Management and leasing fees | Other
Disaggregation of Revenue [Line Items]
Revenue	(63)	(171)	(406)	(339)
Other income
Disaggregation of Revenue [Line Items]
Revenue	10,693	6,673	31,515	21,676
Other income | New York
Disaggregation of Revenue [Line Items]
Revenue	2,736	571	7,666	3,947
Other income | Other
Disaggregation of Revenue [Line Items]
Revenue	$ 7,957	$ 6,102	$ 23,849	$ 17,729