CONSOLIDATED STATEMENTS OF EQUITY - USD ($) shares in Thousands, $ in Thousands	Total Stockholders' Equity	Common Stock	Additional Paid-In Capital	Cumulative Dividends In Excess Of Earnings	Accumulated Other Comprehensive Loss	Noncontrolling Interests	Total
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	725,650			725,650		11,311	736,961
Other comprehensive income (losses)	(2,977)				(2,977)		(2,977)
Issuance of common stock, net	69,825	$ 2,351	67,474			(73)	69,752
Issuance of common stock, net (in shares)		2,351
Repurchase of common stock	(11,599)	$ (297)	(11,302)				(11,599)
Repurchase of common stock (in shares)		(297)
Exercise of stock options	3,307	$ 131	3,176				3,307
Exercise of stock options (in shares)		131
Amortization of deferred compensation	16,467		16,467				16,467
Common dividends ($1.695 and $1.635 per share for the nine months ended September 30, 2015 and 2014, respectively)	(750,835)			(750,835)			(750,835)
Distributions to noncontrolling interests						(11,706)	(11,706)
Issuance of noncontrolling interests						57,354	57,354
Purchase of noncontrolling interests	(13)		(13)			(1,671)	(1,684)
Balance at Sep. 30, 2014	10,773,125	$ 459,146	11,409,843	(1,078,400)	(17,464)	263,049	11,036,174
Balance (in shares) at Sep. 30, 2014		459,146
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
Increase (Decrease) in Stockholders' Equity
Net income	39,633			39,633		8,566	48,199
Other comprehensive income (losses)	(8,555)				(8,555)		(8,555)
Issuance of common stock, net	144,645	$ 4,054	140,591			(2,659)	$ 141,986
Issuance of common stock, net (in shares)		4,054					1,250
Repurchase of common stock	(8,006)	$ (178)	(7,828)				$ (8,006)
Repurchase of common stock (in shares)		(178)
Exercise of stock options	27,511	$ 820	26,691				27,511
Exercise of stock options (in shares)		820
Amortization of deferred compensation	21,068		21,068				21,068
Common dividends ($1.695 and $1.635 per share for the nine months ended September 30, 2015 and 2014, respectively)	(783,578)			(783,578)			(783,578)
Distributions to noncontrolling interests	(263)		(263)			(13,444)	(13,707)
Issuance of noncontrolling interests						38,440	38,440
Balance at Sep. 30, 2015	$ 10,167,752	$ 464,442	$ 11,612,246	$ (1,876,486)	$ (32,450)	$ 292,705	$ 10,460,457
Balance (in shares) at Sep. 30, 2015		464,442