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 (Loss) Income [Member]	Noncontrolling Interest Consolidated Joint Ventures	Noncontrolling Interest Consolidated Real Estate Fund [Member]	Noncontrolling Interest Operating Partnership [Member]
Beginning balance at Dec. 31, 2019	$ 4,630,962	$ 2,274	$ 4,133,184	$ (349,557)	$ (171)	$ 360,778	$ 72,396	$ 412,058
Common stock, shares outstanding at Dec. 31, 2019		227,432,000
Net income (loss)	(6,581)			(9,880)		5,485	(1,291)	(895)
Common shares issued upon redemption of common units		$ 51	85,659
Common shares issued upon redemption of common units, shares		5,150,000
Common shares issued under Omnibus share plan, net of shares withheld for taxes	(318)	$ 1		(319)
Common shares issued under Omnibus share plan, net of shares withheld for taxes		53,000
Redemption of minority interest in operating partnerships								(85,710)
Repurchases of common shares	(108,520)	$ (121)	(108,399)
Repurchases of common shares, shares		(12,090,055)
Dividends and distributions	(72,807)			(66,482)				(6,325)
Contributions from noncontrolling interests	11,555					3,500	8,055
Distributions to noncontrolling interests	(9,530)					(9,530)
Pro rata share of other comprehensive income (loss) of unconsolidated joint ventures	(15,453)				(14,037)		8	(1,424)
Amortization of equity awards	14,252		984					13,268
Sale of a 10.0% interest in 1633 Broadway	109,573		33,230			76,343
Reallocation of noncontrolling interest			(16,171)					16,171
Ending balance at Sep. 30, 2020	4,553,133	$ 2,205	4,128,487	(426,238)	(14,208)	436,576	79,168	347,143
Common stock, shares outstanding at Sep. 30, 2020		220,545,000
Beginning balance at Dec. 31, 2019	4,630,962	$ 2,274	4,133,184	(349,557)	(171)	360,778	72,396	412,058
Common stock, shares outstanding at Dec. 31, 2019		227,432,000
Repurchases of common shares	(120,000)
Repurchases of common shares, shares		(13,813,158)
Ending balance at Dec. 31, 2020	$ 4,515,734	$ 2,188	4,120,173	(456,393)	(12,791)	437,161	79,017	346,379
Common stock, shares outstanding at Dec. 31, 2020	218,817,337	218,817,000
Beginning balance at Jun. 30, 2020	$ 4,587,676	$ 2,219	4,133,542	(397,220)	(15,031)	436,183	79,243	348,740
Common stock, shares outstanding at Jun. 30, 2020		221,764,000
Net income (loss)	(4,123)			(6,958)		3,566	(79)	(652)
Common shares issued upon redemption of common units			399
Common shares issued upon redemption of common units, shares		24,000
Common shares issued under Omnibus share plan, net of shares withheld for taxes	(2)	$ (2)
Common shares issued under Omnibus share plan, net of shares withheld for taxes		(10,000)
Redemption of minority interest in operating partnerships								(399)
Repurchases of common shares	(8,520)	$ (12)	(8,508)
Repurchases of common shares, shares		(1,233,000)
Dividends and distributions	(24,173)			(22,060)				(2,113)
Distributions to noncontrolling interests	(3,173)					(3,173)
Pro rata share of other comprehensive income (loss) of unconsolidated joint ventures	904				823		4	77
Amortization of equity awards	4,544		292					4,252
Reallocation of noncontrolling interest			2,762					(2,762)
Ending balance at Sep. 30, 2020	4,553,133	$ 2,205	4,128,487	(426,238)	(14,208)	436,576	79,168	347,143
Common stock, shares outstanding at Sep. 30, 2020		220,545,000
Beginning balance at Dec. 31, 2020	$ 4,515,734	$ 2,188	4,120,173	(456,393)	(12,791)	437,161	79,017	346,379
Common stock, shares outstanding at Dec. 31, 2020	218,817,337	218,817,000
Net income (loss)	$ (3,612)			(21,576)		16,924	3,179	(2,139)
Common shares issued upon redemption of common units			165
Common shares issued upon redemption of common units, shares		10,000
Common shares issued under Omnibus share plan, net of shares withheld for taxes	(214)	$ 1		(215)
Common shares issued under Omnibus share plan, net of shares withheld for taxes		129,000
Redemption of minority interest in operating partnerships								(165)
Repurchases of common shares, shares		0
Dividends and distributions	(50,683)			(45,981)				(4,702)
Contributions from noncontrolling interests	121					121
Distributions to noncontrolling interests	(19,616)					(19,616)
Change in value of interest rate swaps and interest rate caps	995				905			90
Pro rata share of other comprehensive income (loss) of unconsolidated joint ventures	5,677				5,156		13	508
Amortization of equity awards	14,544		916					13,628
Reallocation of noncontrolling interest			(3,586)					3,586
Other	271		271	(552)		552
Ending balance at Sep. 30, 2021	$ 4,463,217	$ 2,189	4,117,939	(524,717)	(6,730)	435,142	82,209	357,185
Common stock, shares outstanding at Sep. 30, 2021	218,956,406	218,956,000
Beginning balance at Jun. 30, 2021	$ 4,480,123	$ 2,189	4,113,889	(507,321)	(8,478)	442,428	79,085	358,331
Common stock, shares outstanding at Jun. 30, 2021		218,962,000
Net income (loss)	4,632			(2,055)		3,768	3,123	(204)
Common shares issued under Omnibus share plan, net of shares withheld for taxes	(14)			(14)
Common shares issued under Omnibus share plan, net of shares withheld for taxes		(6,000)
Dividends and distributions	(16,897)			(15,327)				(1,570)
Distributions to noncontrolling interests	(11,054)					(11,054)
Change in value of interest rate swaps and interest rate caps	995				905			90
Pro rata share of other comprehensive income (loss) of unconsolidated joint ventures	928				843		1	84
Amortization of equity awards	4,233		305					3,928
Reallocation of noncontrolling interest			3,474					(3,474)
Other	271		271
Ending balance at Sep. 30, 2021	$ 4,463,217	$ 2,189	$ 4,117,939	$ (524,717)	$ (6,730)	$ 435,142	$ 82,209	$ 357,185
Common stock, shares outstanding at Sep. 30, 2021	218,956,406	218,956,000