Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Supplemental cash flow information:
Interest paid, net of capitalized interest	$ 226,907	$ 261,799
Income taxes paid	2,040	9,897
Capitalized interest	13,769	12,607
Supplemental schedule of non-cash investing and financing activities:
Accrued construction costs	78,557	63,515
Retained equity method investment from U.K. JV transaction	104,922	0
Derecognition of U.K. Bridge Loan receivable	147,474	0
Consolidation of net assets related to U.K. Bridge Loan	106,457	0
Deconsolidation of noncontrolling interest in connection with RIDEA II transaction	0	58,061
Vesting of restricted stock units and conversion of non-managing member units into common stock	389	2,464
Other liabilities assumed with real estate acquisitions	$ 2,093	$ 3,678