Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Supplemental cash flow information:
Interest paid, net of capitalized interest	$ 141,777	$ 163,455
Income taxes paid	2,735	10,335
Capitalized interest	8,033	7,628
Supplemental schedule of non-cash investing and financing activities:
Accrued construction costs	66,233	68,618
Retained equity method investment and proceeds receivable from U.K. JV transaction	507,369	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	$ 340	$ 2,451