CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (UNAUDITED) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid in Capital [Member]	Earnings Less than Distributions [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interest Consolidated Joint Ventures [Member]	Noncontrolling Interest Consolidated Real Estate Fund [Member]	Noncontrolling Interest Operating Partnership [Member]
Beginning balance at Dec. 31, 2016	$ 4,885,947	$ 2,300	$ 4,116,987	$ (129,654)	$ 372	$ 253,788	$ 64,793	$ 577,361
Common stock, shares outstanding at Dec. 31, 2016		230,015,000
Net (loss) income	139,811			103,388		3,188	20,081	13,154
Common shares issued upon redemption of common units		$ 82	135,877
Common shares issued upon redemption of common units		8,207,000
Redemption of minority interest in operating partnerships								(135,959)
Common shares issued under Omnibus share plan, net of shares withheld for taxes	(154)			(154)
Common shares issued under Omnibus share plan, net of shares withheld for taxes		62,000
Dividends and distributions	(50,418)			(44,617)				(5,801)
Contributions from noncontrolling interests	9,278					4,973	4,305
Distributions to noncontrolling interests	(107,162)					(32,816)	(74,346)
Change in value of interest rate swaps	(9)				(67)			58
Pro rata share of other comprehensive income (loss) of unconsolidated joint ventures	(187)				(162)			(25)
Amortization of equity awards	8,805		1,522					7,283
Ending balance at Jun. 30, 2017	4,885,911	$ 2,382	4,254,386	(71,037)	143	229,133	14,833	456,071
Common stock, shares outstanding at Jun. 30, 2017		238,284,000
Beginning balance (Restatement Adjustment)	5,029,170	$ 2,403	4,297,948	(133,164)	10,083	404,997	21,106	425,797
Beginning balance at Dec. 31, 2017	5,022,084	$ 2,403	4,297,948	(133,693)	10,083	404,997	14,549	425,797
Beginning balance (Basis adjustment upon adoption of ASU 2017-05) at Dec. 31, 2017	$ 7,086			529			6,557
Common stock, shares outstanding (Restatement Adjustment)		240,427,000
Common stock, shares outstanding at Dec. 31, 2017	240,427,022	240,427,000
Net (loss) income	$ (33,863)			(33,702)		2,807	582	(3,550)
Common shares issued upon redemption of common units			469
Common shares issued upon redemption of common units		27,000
Redemption of minority interest in operating partnerships								(469)
Common shares issued under Omnibus share plan, net of shares withheld for taxes	(213)			(213)
Common shares issued under Omnibus share plan, net of shares withheld for taxes		75,000
Dividends and distributions	(53,247)			(48,103)				(5,144)
Contributions from noncontrolling interests	36,128						36,128
Distributions to noncontrolling interests	(4,118)					(4,118)
Change in value of interest rate swaps	20,346				18,422			1,924
Pro rata share of other comprehensive income (loss) of unconsolidated joint ventures	157				142			15
Amortization of equity awards	11,558		1,470					10,088
Other	(170)		(2,064)	(171)				2,065
Ending balance at Jun. 30, 2018	$ 5,005,748	$ 2,403	$ 4,297,823	$ (215,353)	$ 28,647	$ 403,686	$ 57,816	$ 430,726
Common stock, shares outstanding at Jun. 30, 2018	240,529,397	240,529,000