Segment Information (Summary of NOI by Segment) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Information
Total revenues	$ 379,977	$ 444,532
Operating expenses	(190,979)	(230,007)
NOI - consolidated	188,998	214,525
Deduct: NOI attributable to noncontrolling interests in consolidated subsidiaries	(17,646)	(15,493)
Add: NOI from partially owned entities	78,756	81,881
NOI at share	250,108	280,913
Non-cash adjustments for straight-line rents, amortization of acquired below-market leases, net, and other	(1,198)	3,076
NOI at share - cash basis	248,910	283,989
New York
Segment Information
Total revenues	303,971	355,615
Operating expenses	(160,985)	(183,031)
NOI - consolidated	142,986	172,584
Deduct: NOI attributable to noncontrolling interests in consolidated subsidiaries	(8,621)	(8,433)
Add: NOI from partially owned entities	76,773	78,408
NOI at share	211,138	242,559
Non-cash adjustments for straight-line rents, amortization of acquired below-market leases, net, and other	(973)	1,106
NOI at share - cash basis	210,165	243,665
Other
Segment Information
Total revenues	76,006	88,917
Operating expenses	(29,994)	(46,976)
NOI - consolidated	46,012	41,941
Deduct: NOI attributable to noncontrolling interests in consolidated subsidiaries	(9,025)	(7,060)
Add: NOI from partially owned entities	1,983	3,473
NOI at share	38,970	38,354
Non-cash adjustments for straight-line rents, amortization of acquired below-market leases, net, and other	(225)	1,970
NOI at share - cash basis	$ 38,745	$ 40,324