Condensed Consolidated Statements of Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income	Noncontrolling Interests in Consolidated Subsidiaries	Total
Balance at beginning of period at Dec. 31, 2018	$ 1,210	$ 3,155,256	$ (176,018)	$ 6,700	$ 204	$ 2,987,352
Balance at beginning of period (in shares) at Dec. 31, 2018	120,937
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to common shareholders and noncontrolling interests			21,821			21,821
Common shares issued	$ 115	472,665				472,780
Common shares issued (in shares)	11,500
Conversion of common limited partnership units to common shares	$ 17	57,301				57,318
Conversion of common limited partnership units to common shares (in shares)	1,664
Common shares issued pursuant to Employee Share Purchase Plan		938				938
Common shares issued pursuant to Employee Share Purchase Plan ( in shares)	26
Dividends declared on common shares			(30,176)			(30,176)
Contributions from (distributions to) noncontrolling interests					142	142
Redeemable noncontrolling interests redemption value adjustment and other comprehensive loss allocation		(41,461)		2,886		(38,575)
Other comprehensive loss				(28,742)		(28,742)
Balance at end of period (in shares) at Jun. 30, 2019	134,127
Balance at end of period at Jun. 30, 2019	$ 1,342	3,644,699	(184,373)	(19,156)	346	3,442,858
Balance at beginning of period at Mar. 31, 2019	$ 1,227	3,150,133	(151,157)	(3,452)	365	2,997,116
Balance at beginning of period (in shares) at Mar. 31, 2019	122,594
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to common shareholders and noncontrolling interests			(3,040)			(3,040)
Common shares issued	$ 115	472,665				472,780
Common shares issued (in shares)	11,500
Conversion of common limited partnership units to common shares		316				316
Conversion of common limited partnership units to common shares (in shares)	7
Common shares issued pursuant to Employee Share Purchase Plan		834				834
Common shares issued pursuant to Employee Share Purchase Plan ( in shares)	26
Dividends declared on common shares			(30,176)			(30,176)
Contributions from (distributions to) noncontrolling interests					(19)	(19)
Redeemable noncontrolling interests redemption value adjustment and other comprehensive loss allocation		20,751		1,503		22,254
Other comprehensive loss				(17,207)		(17,207)
Balance at end of period (in shares) at Jun. 30, 2019	134,127
Balance at end of period at Jun. 30, 2019	$ 1,342	3,644,699	(184,373)	(19,156)	346	3,442,858
Balance at beginning of period at Dec. 31, 2019	$ 1,342	3,633,042	(231,164)	(16,744)	201	$ 3,386,677
Balance at beginning of period (in shares) at Dec. 31, 2019	134,148					134,148
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to common shareholders and noncontrolling interests			6,145			$ 6,145
Conversion of common limited partnership units to common shares	$ 10	35,868				35,878
Conversion of common limited partnership units to common shares (in shares)	943
Common shares repurchased	$ (14)	(41,178)				(41,192)
Common shares repurchased (in shares)	(1,418)
Common shares issued pursuant to Employee Share Purchase Plan		1,134				1,134
Common shares issued pursuant to Employee Share Purchase Plan ( in shares)	35
Dividends declared on common shares			(30,143)			(30,143)
Contributions from (distributions to) noncontrolling interests					(10)	(10)
Redeemable noncontrolling interests redemption value adjustment and other comprehensive loss allocation		113,339		3,755		117,094
Other comprehensive loss				(34,897)		$ (34,897)
Balance at end of period (in shares) at Jun. 30, 2020	133,708					133,708
Balance at end of period at Jun. 30, 2020	$ 1,338	3,742,205	(255,162)	(47,886)	191	$ 3,440,686
Balance at beginning of period at Mar. 31, 2020	$ 1,336	3,723,795	(188,239)	(45,941)	203	3,491,154
Balance at beginning of period (in shares) at Mar. 31, 2020	133,517
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss) attributable to common shareholders and noncontrolling interests			(36,780)			(36,780)
Conversion of common limited partnership units to common shares	$ 2	4,750				4,752
Conversion of common limited partnership units to common shares (in shares)	156
Common shares repurchased		(15)				(15)
Common shares issued pursuant to Employee Share Purchase Plan		1,002				1,002
Common shares issued pursuant to Employee Share Purchase Plan ( in shares)	35
Dividends declared on common shares			(30,143)			(30,143)
Contributions from (distributions to) noncontrolling interests					(12)	(12)
Redeemable noncontrolling interests redemption value adjustment and other comprehensive loss allocation		12,673		182		12,855
Other comprehensive loss				(2,127)		$ (2,127)
Balance at end of period (in shares) at Jun. 30, 2020	133,708					133,708
Balance at end of period at Jun. 30, 2020	$ 1,338	$ 3,742,205	$ (255,162)	$ (47,886)	$ 191	$ 3,440,686