CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	Total Stockholders' Equity	Common Stock	Additional Paid-in Capital	Retained Earnings (Accumulated Deficit)	Noncontrolling Interests
Balance (in shares) at Dec. 31, 2013			140,733,683
Balance at Dec. 31, 2013	$ 3,718,717	$ 3,358,749	$ 1,407	$ 3,906,148	$ (548,806)	$ 359,968
Increase (Decrease) in Stockholders' Equity
Net income	1,606,931	1,499,042			1,499,042	107,889
Amortization of share and unit-based plans (in shares)			168,379
Amortization of share and unit-based plans	34,873	34,873	$ 2	34,871
Employee stock purchases (in shares)			25,007
Employee stock purchases	1,231	1,231		1,231
Stock issued to acquire properties (in shares)			17,140,845
Stock issued to acquire properties	1,161,274	1,161,274	$ 172	1,161,102
Distributions	(353,495)	(353,495)			(353,495)
Distributions to noncontrolling interests	(32,230)					(32,230)
Change in noncontrolling interests due to acquisition/disposition of consolidated entities	(97,216)	(3,858)		(3,858)		(93,358)
Conversion of noncontrolling interests to common shares (in shares)			134,082
Conversion of noncontrolling interests to common shares	0	2,410	$ 1	2,409		(2,410)
Redemption of noncontrolling interests	(236)	(157)		(157)		(79)
Adjustment of noncontrolling interests in Operating Partnership	0	(59,949)		(59,949)		59,949
Balance (in shares) at Dec. 31, 2014			158,201,996
Balance at Dec. 31, 2014	6,039,849	5,640,120	$ 1,582	5,041,797	596,741	399,729
Increase (Decrease) in Stockholders' Equity
Net income	522,912	487,562			487,562	35,350
Amortization of share and unit-based plans (in shares)			241,186
Amortization of share and unit-based plans	34,375	34,375	$ 2	34,373
Employee stock purchases (in shares)			23,036
Employee stock purchases	1,512	1,512		1,512
Stock repurchase (in shares)			(4,140,788)
Stock repurchase	(400,144)	(400,144)	$ (41)	(153,602)	(246,501)
Distributions	(1,050,562)	(1,050,562)			(1,050,562)
Distributions to noncontrolling interests	(74,677)					(74,677)
Contributions from noncontrolling interests	23					23
Other	(1,593)	(1,593)		(1,593)
Conversion of noncontrolling interests to common shares (in shares)			79,556
Conversion of noncontrolling interests to common shares	0	1,559	$ 1	1,558		(1,559)
Redemption of noncontrolling interests	(456)	(343)		(343)		(113)
Adjustment of noncontrolling interests in Operating Partnership	$ 0	2,928		2,928		(2,928)
Balance (in shares) at Dec. 31, 2015	154,404,986		154,404,986
Balance at Dec. 31, 2015	$ 5,071,239	4,715,414	$ 1,544	4,926,630	(212,760)	355,825
Increase (Decrease) in Stockholders' Equity
Net income	554,839	516,995			516,995	37,844
Amortization of share and unit-based plans (in shares)			139,671
Amortization of share and unit-based plans	40,529	40,529	$ 2	40,527
Employee stock purchases (in shares)			28,147
Employee stock purchases	1,697	1,697		1,697
Stock repurchase (in shares)			(11,123,011)
Stock repurchase	(800,018)	(800,018)	$ (111)	(412,391)	(387,516)
Distributions	(405,501)	(405,501)			(405,501)
Distributions to noncontrolling interests	(35,677)					(35,677)
Contributions from noncontrolling interests	90					90
Conversion of noncontrolling interests to common shares (in shares)			535,243
Conversion of noncontrolling interests to common shares	0	12,448	$ 5	12,443		(12,448)
Redemption of noncontrolling interests	(30)	(23)		(23)		(7)
Adjustment of noncontrolling interests in Operating Partnership	$ 0	24,346		24,346		(24,346)
Balance (in shares) at Dec. 31, 2016	143,985,036		143,985,036
Balance at Dec. 31, 2016	$ 4,427,168	$ 4,105,887	$ 1,440	$ 4,593,229	$ (488,782)	$ 321,281