Revenue Recognition (Revenues by Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Lease income	$ 382,683	$ 390,408	$ 1,168,395	$ 1,162,330
Total revenues	$ 450,995	$ 457,431	$ 1,369,277	$ 1,353,055
Operating Lease, Lease Income, Statement of Income or Comprehensive Income [Extensible Enumeration]	Total revenues	Total revenues	Total revenues	Total revenues
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
New York
Disaggregation of Revenue [Line Items]
Total revenues	$ 364,768	$ 360,033	1,091,053	$ 1,082,743
Other
Disaggregation of Revenue [Line Items]
Total revenues	86,227	97,398	278,224	270,312
Rental revenues
Disaggregation of Revenue [Line Items]
Total revenues	400,367	409,144	1,215,994	1,211,621
Rental revenues | New York
Disaggregation of Revenue [Line Items]
Total revenues	319,456	317,331	955,674	958,216
Rental revenues | Other
Disaggregation of Revenue [Line Items]
Total revenues	80,911	91,813	260,320	253,405
Lease revenues
Disaggregation of Revenue [Line Items]
Lease income	382,683	390,408	1,168,395	1,162,330
Lease revenues | New York
Disaggregation of Revenue [Line Items]
Lease income	306,717	303,574	919,621	921,179
Lease revenues | Other
Disaggregation of Revenue [Line Items]
Lease income	75,966	86,834	248,774	241,151
Property rentals
Disaggregation of Revenue [Line Items]
Lease income	376,505	371,754	1,150,387	1,132,690
Property rentals | New York
Disaggregation of Revenue [Line Items]
Lease income	306,717	303,574	919,621	921,179
Property rentals | Other
Disaggregation of Revenue [Line Items]
Lease income	69,788	68,180	230,766	211,511
Trade shows
Disaggregation of Revenue [Line Items]
Lease income	6,178	18,654	18,008	29,640
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	6,178	18,654	18,008	29,640
Tenant services
Disaggregation of Revenue [Line Items]
Revenue	12,793	14,134	32,366	35,484
Tenant services | New York
Disaggregation of Revenue [Line Items]
Revenue	8,789	9,937	23,696	25,481
Tenant services | Other
Disaggregation of Revenue [Line Items]
Revenue	4,004	4,197	8,670	10,003
Parking revenues
Disaggregation of Revenue [Line Items]
Revenue	4,891	4,602	15,233	13,807
Parking revenues | New York
Disaggregation of Revenue [Line Items]
Revenue	3,950	3,820	12,357	11,556
Parking revenues | Other
Disaggregation of Revenue [Line Items]
Revenue	941	782	2,876	2,251
Fee and other income
Disaggregation of Revenue [Line Items]
Revenue	50,628	48,287	153,283	141,434
Total revenues	50,628	48,287	153,283	141,434
Fee and other income | New York
Disaggregation of Revenue [Line Items]
Revenue	45,312	42,702	135,379	124,527
Fee and other income | Other
Disaggregation of Revenue [Line Items]
Revenue	5,316	5,585	17,904	16,907
BMS cleaning fees
Disaggregation of Revenue [Line Items]
Revenue	35,428	35,062	105,902	101,752
BMS cleaning fees | New York
Disaggregation of Revenue [Line Items]
Revenue	37,999	37,371	113,431	108,288
BMS cleaning fees | Other
Disaggregation of Revenue [Line Items]
Revenue	(2,571)	(2,309)	(7,529)	(6,536)
Management and leasing fees
Disaggregation of Revenue [Line Items]
Revenue	3,263	2,532	9,970	8,167
Management and leasing fees | New York
Disaggregation of Revenue [Line Items]
Revenue	3,441	2,595	10,375	8,573
Management and leasing fees | Other
Disaggregation of Revenue [Line Items]
Revenue	(178)	(63)	(405)	(406)
Other income
Disaggregation of Revenue [Line Items]
Revenue	11,937	10,693	37,411	31,515
Other income | New York
Disaggregation of Revenue [Line Items]
Revenue	3,872	2,736	11,573	7,666
Other income | Other
Disaggregation of Revenue [Line Items]
Revenue	$ 8,065	$ 7,957	$ 25,838	$ 23,849