Segment Information (Summary of NOI by Segment) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Information
Total revenues	$ 378,941	$ 343,026	$ 758,918	$ 787,558
Operating expenses	(190,920)	(174,425)	(381,899)	(404,432)
NOI - consolidated	188,021	168,601	377,019	383,126
Deduct: NOI attributable to noncontrolling interests in consolidated subsidiaries	(15,689)	(15,448)	(33,335)	(30,941)
Add: NOI from partially owned entities	77,235	69,487	155,991	151,368
NOI at share	249,567	222,640	499,675	503,553
Non-cash adjustments for straight-line rents, amortization of acquired below-market leases, net, and other	846	34,190	(352)	37,266
NOI at share - cash basis	250,413	256,830	499,323	540,819
New York
Segment Information
Total revenues	301,144	270,628	605,115	626,243
Operating expenses	(156,033)	(140,207)	(317,018)	(323,238)
NOI - consolidated	145,111	130,421	288,097	303,005
Deduct: NOI attributable to noncontrolling interests in consolidated subsidiaries	(8,473)	(8,504)	(17,094)	(16,937)
Add: NOI from partially owned entities	74,400	67,051	151,173	145,459
NOI at share	211,038	188,968	422,176	431,527
Non-cash adjustments for straight-line rents, amortization of acquired below-market leases, net, and other	541	32,943	(432)	34,049
NOI at share - cash basis	211,579	221,911	421,744	465,576
Other
Segment Information
Total revenues	77,797	72,398	153,803	161,315
Operating expenses	(34,887)	(34,218)	(64,881)	(81,194)
NOI - consolidated	42,910	38,180	88,922	80,121
Deduct: NOI attributable to noncontrolling interests in consolidated subsidiaries	(7,216)	(6,944)	(16,241)	(14,004)
Add: NOI from partially owned entities	2,835	2,436	4,818	5,909
NOI at share	38,529	33,672	77,499	72,026
Non-cash adjustments for straight-line rents, amortization of acquired below-market leases, net, and other	305	1,247	80	3,217
NOI at share - cash basis	$ 38,834	$ 34,919	$ 77,579	$ 75,243