CONSOLIDATED STATEMENT OF EQUITY (USD $) In Thousands	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid in Capital [Member]	Accumulated Other Comprehensive Income (loss) [Member]	Distributions in excess of earnings [Member]	Total Shareholders' Equity [Member]	Non-Controlling Interest [Member]
Balance at January 1, 2012 at Dec. 31, 2011	$ 1,917,413		$ 1,154	$ 2,299,543	$ (393,291)	$ (15,068)	$ 1,892,338	$ 25,075
Balance, shares at Dec. 31, 2011			115,395,695
Net income	250,678					247,653	247,653	3,025
Other comprehensive income	512,080				505,834		505,834	6,246
Proceeds from issuance of common stock, net of offering costs	153			153			153
Proceeds from issuance of common stock, net of offering costs, shares			8,504
Proceeds from issuance of preferred stock, net of offering costs	135,359	135,359					135,359
Proceeds from issuance of preferred stock, net of offering costs, shares		5,600,000
Stock awards			9,987
Common stock dividends	(225,048)					(225,048)	(225,048)
Common unit dividends	(2,779)							(2,779)
Preferred stock dividends	(2,682)					(2,682)	(2,682)
Amortization of equity-based compensation	257			254			254	3
Balance at September 30, 2012 at Sep. 30, 2012	$ 2,585,431	$ 135,359	$ 1,154	$ 2,299,950	$ 112,543	$ 4,855	$ 2,553,861	$ 31,570
Balance, shares at Sep. 30, 2012		5,600,000	115,414,186