CONSOLIDATED STATEMENTS OF EQUITY (USD $) In Thousands, unless otherwise specified	Total Stockholders' Equity	Preferred Stock	Common Stock	Additional Paid-In Capital	Cumulative Dividends In Excess Of Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests	Total
Balance at Dec. 31, 2011	$ 9,033,482	$ 285,173	$ 408,629	$ 9,383,536	$ (1,024,274)	$ (19,582)	$ 187,140	$ 9,220,622
Balance (in shares) at Dec. 31, 2011		11,820	408,629
Increase (Decrease) in Stockholders' Equity
Net income	832,540				832,540		14,302	846,842
Other comprehensive income (losses)	4,929					4,929		4,929
Preferred stock redemption	(295,500)	(285,173)			(10,327)			(295,500)
Preferred stock redemption (in shares)		(11,820)
Issuance of common stock, net	1,781,825		42,468	1,739,357			(25,029)	1,756,796
Issuance of common stock, net (in shares)			42,468
Repurchase of common stock	(15,632)		(361)	(15,271)				(15,632)
Repurchase of common stock (in shares)			(361)
Exercise of stock options	51,622		2,455	49,167				51,622
Exercise of stock options (in shares)			2,455
Amortization of deferred compensation	23,277			23,277				23,277
Preferred dividends	(6,679)				(6,679)			(6,679)
Common dividends ($2.18, $2.10 and $2.00 per share for the year ended 2014, 2013 and 2012, respectively)	(858,627)				(858,627)			(858,627)
Distributions to noncontrolling interests							(15,631)	(15,631)
Noncontrolling interests in acquisitions							42,734	42,734
Issuance of noncontrolling interests							1,584	1,584
Purchase of noncontrolling interests							(2,560)	(2,560)
Balance at Dec. 31, 2012	10,551,237		453,191	11,180,066	(1,067,367)	(14,653)	202,540	10,753,777
Balance (in shares) at Dec. 31, 2012			453,191
Increase (Decrease) in Stockholders' Equity
Net income	970,837				970,837		14,169	985,006
Other comprehensive income (losses)	166					166		166
Issuance of common stock, net	110,701		3,136	107,565			(3,683)	107,018
Issuance of common stock, net (in shares)			3,136
Repurchase of common stock	(10,438)		(242)	(10,196)				(10,438)
Repurchase of common stock (in shares)			(242)
Exercise of stock options	17,502		876	16,626				17,502
Exercise of stock options (in shares)			876
Amortization of deferred compensation	39,980			39,980				39,980
Common dividends ($2.18, $2.10 and $2.00 per share for the year ended 2014, 2013 and 2012, respectively)	(956,685)				(956,685)			(956,685)
Distributions to noncontrolling interests							(17,664)	(17,664)
Issuance of noncontrolling interests							12,472	12,472
Balance at Dec. 31, 2013	10,723,300		456,961	11,334,041	(1,053,215)	(14,487)	207,834	10,931,134
Balance (in shares) at Dec. 31, 2013			456,961
Increase (Decrease) in Stockholders' Equity
Net income	922,233				922,233		14,358	936,591
Other comprehensive income (losses)	(9,408)					(9,408)		(9,408)
Issuance of common stock, net	92,688		2,939	89,749			(557)	92,131
Issuance of common stock, net (in shares)			2,939
Repurchase of common stock	(12,703)		(323)	(12,380)				(12,703)
Repurchase of common stock (in shares)			(323)
Exercise of stock options	4,461		169	4,292				4,461
Exercise of stock options (in shares)			169
Amortization of deferred compensation	21,885			21,885				21,885
Common dividends ($2.18, $2.10 and $2.00 per share for the year ended 2014, 2013 and 2012, respectively)	(1,001,559)				(1,001,559)			(1,001,559)
Distributions to noncontrolling interests							(15,611)	(15,611)
Issuance of noncontrolling interests							57,746	57,746
Purchase of noncontrolling interests	(5,600)			(5,600)			(1,968)	(7,568)
Balance at Dec. 31, 2014	$ 10,735,297		$ 459,746	$ 11,431,987	$ (1,132,541)	$ (23,895)	$ 261,802	$ 10,997,099
Balance (in shares) at Dec. 31, 2014			459,746