Segment Information (Summary of net income and EBITDA reconciliation by segment) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting [Abstract]
Net income	$ 213,044	$ 282
(Income) loss from partially owned entities	(7,320)	9,904
Interest and other investment (income) loss, net	(5,045)	24,384
Net gains on disposition of wholly owned and partially owned assets	(220,294)	0
NOI attributable to noncontrolling interests in consolidated subsidiaries	(17,403)	(17,312)
Loss from real estate fund investments	167	8,807
Depreciation and amortization expense	116,709	108,686
General and administrative expense	58,020	42,533
Transaction related costs and other	149	13,156
NOI from partially owned entities	67,402	67,513
Interest and debt expense	102,463	88,166
Loss from discontinued operations	137	363
Income tax expense	29,743	2,554
NOI at share	337,772	349,036
Non-cash adjustments for straight-line rents, amortization of acquired below-market leases, net, and other	(5,181)	(17,948)
NOI at share - cash basis	$ 332,591	$ 331,088