CONSOLIDATED STATEMENTS OF EQUITY (USD $) In Thousands, unless otherwise specified	Total	Common Stock	Preferred Stock	Additional Paid-In Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests in Consolidated Real Estate Affiliates
Balance at Dec. 31, 2011	$ 8,579,345	$ 9,353		$ 10,405,318	$ (1,883,569)	$ (47,773)	$ 96,016
Increase (Decrease) in Shareholders' Equity
Net (loss) income	(198,364)				(197,615)		(749)
Distributions to noncontrolling interests in consolidated Real Estate Affiliates	(357)						(357)
Restricted stock grants, net of forfeitures and compensation expense (24,121 and 12,311 common shares for the three months ended March 31, 2013 and 2012, respectively)	1,984			1,984
Stock option grants, net of forfeitures (213,534 and 11,235 common shares for the three months ended March 31, 2013 and 2012, respectively)	740			740
Cash dividends reinvested (DRIP) in stock (7,178 and 2,294,864 common shares for the three months ended March 31, 2013 and 2012, respectively)	33,574	23		33,551
Other comprehensive income	13,514					13,514
Cash distributions declared ($0.12 and $0.10 per share for the three months ended March 31, 2013 and 2012, respectively)	(93,759)				(93,759)
Fair value adjustment for noncontrolling interest in Operating Partnership	(16,119)			(16,119)
Dividend for RPI Spin-off	21,988				21,988
Balance at Mar. 31, 2012	8,342,546	9,376		10,425,474	(2,152,955)	(34,259)	94,910
Balance at Dec. 31, 2012	7,705,020	9,392		10,432,447	(2,732,787)	(87,354)	83,322
Increase (Decrease) in Shareholders' Equity
Net (loss) income	(10,989)				(11,526)		537
Issuance of preferred stock, net of issuance costs	242,042		242,042
Distributions to noncontrolling interests in consolidated Real Estate Affiliates	(853)						(853)
Restricted stock grants, net of forfeitures and compensation expense (24,121 and 12,311 common shares for the three months ended March 31, 2013 and 2012, respectively)	2,401			2,401
Employee stock purchase program (84,798 common shares)	1,668			1,668
Stock option grants, net of forfeitures (213,534 and 11,235 common shares for the three months ended March 31, 2013 and 2012, respectively)	22,694	2		22,692
Cash dividends reinvested (DRIP) in stock (7,178 and 2,294,864 common shares for the three months ended March 31, 2013 and 2012, respectively)	139			139
Other comprehensive income	9,843					9,843
Cash distributions declared ($0.12 and $0.10 per share for the three months ended March 31, 2013 and 2012, respectively)	(112,768)				(112,768)
Cash distributions on preferred stock	(2,125)				(2,125)
Cash redemptions for common units in excess of carrying value	(1,428)			(1,428)
Fair value adjustment for noncontrolling interest in Operating Partnership	427			427
Common stock warrants	895,513			895,513
Balance at Mar. 31, 2013	$ 8,751,584	$ 9,394	$ 242,042	$ 11,353,859	$ (2,859,206)	$ (77,511)	$ 83,006