Consolidated Statements of Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock	Additional Paid-In Capital	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Noncontrolling Interests	Series I Preferred Stock Preferred Stock
Beginning Balance at Dec. 31, 2013	$ 7,016,876	$ 986	$ 5,015,904	$ (317,356)	$ (15,211)	$ 1,619,150	$ 491,471	$ 221,932
Shares outstanding (shares) at Dec. 31, 2013		94,993,000
Increase (Decrease) in Stockholders' Equity
Net income	462,578					457,533	5,045
Other comprehensive income	12,315				12,315
Preferred dividends	(11,214)					(11,214)
DRIP proceeds	40		40
Conversion of units of the Operating Partnership to common stock	26,392	3	26,389
Conversion of units of the Operating Partnership to common stock (in shares)		264,000
Reallocation of noncontrolling interest in the Operating Partnership	(108,453)					(108,453)
Deferred compensation plan and stock award, net	(1,363)	0	1,503	(2,866)
Deferred compensation plan and stock award, net (in shares)		4,000
Amortization of deferred compensation plan	23,822		23,822
Issuance of common stock	42,698	4	42,694
Issuance of common stock (shares)		394,000
Proceeds from stock options exercised	20,509	3	20,506
Proceeds from issuance of common stock (in shares)		290,000
Contributions to consolidated joint venture interests	28,058						28,058
Cash distributions to noncontrolling interests	(5,745)						(5,745)
Cash distributions declared ($1.50 per common share, none of which represented a return of capital for federal income tax purposes)	(143,060)					(143,060)
Ending Balance at Sep. 30, 2014	$ 7,363,453	$ 996	$ 5,130,858	$ (320,222)	$ (2,896)	$ 1,813,956	$ 518,829	$ 221,932
Shares outstanding (shares) at Sep. 30, 2014		95,945,000