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 income (loss)	1,629			372		1,291	(88)	54
Common shares issued upon redemption of common units		$ 13	21,803
Common shares issued upon redemption of common units		1,304,000
Redemption of minority interest in operating partnerships								(21,816)
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		61,000
Dividends and distributions	(25,207)			(21,981)				(3,226)
Contributions from noncontrolling interests in joint ventures and funds	7,472					4,972	2,500
Distributions to noncontrolling interests	(32,012)					(32,012)
Change in value of interest rate swaps	4,032				3,518			514
Pro rata share of other comprehensive income (loss) of unconsolidated joint ventures	(222)				(194)			(28)
Amortization of equity awards	3,873		633					3,240
Ending balance at Mar. 31, 2017	4,845,358	$ 2,313	4,139,423	(151,417)	3,696	228,039	67,205	556,099
Common stock, shares outstanding at Mar. 31, 2017		231,380,000
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 income (loss)	$ 2,715			1,114		1,055	430	116
Common shares issued upon redemption of common units			123
Common shares issued upon redemption of common units		7,000
Redemption of minority interest in operating partnerships								(123)
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		72,000
Dividends and distributions	(26,627)			(24,051)				(2,576)
Contributions from noncontrolling interests in joint ventures and funds	29,920						29,920
Distributions to noncontrolling interests	(1,915)					(1,915)
Change in value of interest rate swaps	14,551				13,179			1,372
Pro rata share of other comprehensive income (loss) of unconsolidated joint ventures	54				50			4
Amortization of equity awards	6,584		838					5,746
Other	(169)		(5,700)	(171)				5,702
Ending balance at Mar. 31, 2018	$ 5,054,070	$ 2,403	$ 4,293,209	$ (156,485)	$ 23,312	$ 404,137	$ 51,456	$ 436,038
Common stock, shares outstanding at Mar. 31, 2018	240,505,886	240,506,000