CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Total	Previously Reported [Member]	Restatement Adjustment [Member]	Common Stock [Member]	Common Stock [Member] Previously Reported [Member]	Common Stock [Member] Restatement Adjustment [Member]	Additional Paid in Capital [Member]	Additional Paid in Capital [Member] Previously Reported [Member]	Additional Paid in Capital [Member] Restatement Adjustment [Member]	Earnings Less than Distributions [Member]	Earnings Less than Distributions [Member] Previously Reported [Member]	Earnings Less than Distributions [Member] Restatement Adjustment [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Other Comprehensive Income (Loss) [Member] Previously Reported [Member]	Accumulated Other Comprehensive Income (Loss) [Member] Restatement Adjustment [Member]	Noncontrolling Interest [Member] Consolidated Joint Ventures [Member]	Noncontrolling Interest [Member] Consolidated Joint Ventures [Member] Previously Reported [Member]	Noncontrolling Interest [Member] Consolidated Joint Ventures [Member] Restatement Adjustment [Member]	Noncontrolling Interest [Member] Consolidated Real Estate Fund [Member]	Noncontrolling Interest [Member] Consolidated Real Estate Fund [Member] Previously Reported [Member]	Noncontrolling Interest [Member] Consolidated Real Estate Fund [Member] Restatement Adjustment [Member]	Noncontrolling Interest [Member] Operating Partnership [Member]	Noncontrolling Interest [Member] Operating Partnership [Member] Previously Reported [Member]	Noncontrolling Interest [Member] Operating Partnership [Member] Restatement Adjustment [Member]
Beginning balance at Dec. 31, 2015	$ 4,959,515	$ 5,310,550		$ 2,122	$ 2,122		$ 3,802,858	$ 3,802,858		$ (36,120)	$ (36,120)		$ (7,843)	$ (7,843)		$ 236,849	$ 236,849		$ 63,602	$ 414,637		$ 898,047	$ 898,047
Beginning balance (Deconsolidation of real estate fund investments upon adoption of ASU 2015-02 [Member]) at Dec. 31, 2015			$ (351,035)																		$ (351,035)
Common stock, shares outstanding at Dec. 31, 2015				212,112,000	212,112,000
Net income (loss)	2,069									(9,934)						15,423			(1,316)			(2,104)
Common shares issued upon redemption of common units				$ 178			312,079
Common shares issued upon redemption of common units				17,808,000
Redemption of minority interest in operating partnerships																						(312,257)
Common shares issued under Omnibus share plan, net of shares withheld for taxes				95,000
Dividends and distributions	(100,601)									(83,805)												(16,796)
Contributions from noncontrolling interests	7,651															5,151			2,500
Distributions to noncontrolling interests	(3,636)															(3,636)
Change in value of interest rate swaps	8,161												8,203									(42)
Pro rata share of other comprehensive income (loss) of unconsolidated joint ventures	17												12									5
Amortization of equity awards	12,528						2,034															10,494
Other	243						16			205						1			7			14
Ending 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)	107,176									86,381						(10,365)			19,797			11,363
Common shares issued upon redemption of common units				$ 103			172,625
Common shares issued upon redemption of common units				10,359,000
Redemption of minority interest in operating partnerships																						(172,728)
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				53,000
Dividends and distributions	(100,840)									(90,266)												(10,574)
Contributions from noncontrolling interests	100,777															96,472			4,305
Distributions to noncontrolling interests	(119,251)															(44,905)			(74,346)
Consolidation of 50 Beale Street	110,007															110,007
Change in value of interest rate swaps	10,618												9,559									1,059
Pro rata share of other comprehensive income (loss) of unconsolidated joint ventures	160												152									8
Amortization of equity awards	18,790						3,085															15,705
Other	8,854						5,251															3,603
Ending balance at Dec. 31, 2017	5,022,084		$ 5,029,170	$ 2,403		$ 2,403	4,297,948		$ 4,297,948	(133,693)		$ (133,164)	10,083		$ 10,083	404,997		$ 404,997	14,549		$ 21,106	425,797		$ 425,797
Ending balance (Basis adjustment upon adoption of ASU 2017-05 [Member]) at Dec. 31, 2017	$ 7,086									529									6,557
Common stock, shares outstanding at Dec. 31, 2017	240,427,022			240,427,000		240,427,000
Net income (loss)	$ 18,993									9,147						8,182			720			944
Common shares issued upon redemption of common units				$ 2			3,459
Common shares issued upon redemption of common units				203,000
Redemption of minority interest in operating partnerships																						(3,461)
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				61,000
Repurchases of common shares	(105,383)			$ (76)			(105,307)
Repurchases of common shares				(7,555,000)
Dividends and distributions	(105,746)									(95,506)												(10,240)
Contributions from noncontrolling interests	45,116																		45,116
Distributions to noncontrolling interests	(18,184)															(18,184)
Change in value of interest rate swaps	7,273												6,605									668
Pro rata share of other comprehensive income (loss) of unconsolidated joint ventures	(129)												(67)						(55)			(7)
Amortization of equity awards	20,937						2,943															17,994
Other	(170)						2,713			(170)												(2,713)
Ending balance at Dec. 31, 2018	$ 4,891,664			$ 2,329			$ 4,201,756			$ (219,906)			$ 16,621			$ 394,995			$ 66,887			$ 428,982
Common stock, shares outstanding at Dec. 31, 2018	233,135,704			233,136,000