Consolidated Statements of Changes in Equity (Unaudited) (USD $) In Thousands, except Share data	Total	Common Stock	Additional Paid-in Capital	Accumulated Distributions in excess of Net Loss	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests	Noncontrolling Redeemable Interests
Balance, value at Dec. 31, 2010	$ 5,263,392	$ 846	$ 7,605,105	$ (2,409,370)	$ 49,430	$ 17,381	$ 264,132
Balance, shares at Dec. 31, 2010		846,406,774
Net income (loss)	(83,727)	0	0	(82,389)	0	(1,338)	5,209
Unrealized gain/loss on investment securities	(1,356)	0	0	0	(1,356)	0	0
Reversal of unrealized (gain) loss to realized gain (loss) and impairment on securities	(6,891)	0	0	0	(6,891)	0	0
Unrealized gain/loss on derivatives	(170)	0	0	0	(170)	0	0
Distributions declared	(213,753)	0	0	(213,389)	0	(364)	(5,209)
Adjustment to redemption value for noncontrolling redeemable interest	(29,348)	0	(16,249)	0	0	(13,099)	29,348
Proceeds from distribution reinvestment plan, value	99,960	13	99,947	0	0	0	0
Proceeds from distribution reinvestment plan, shares		12,448,526
Share repurchase program, value	(5,000)	(1)	(4,999)	0	0	0	0
Share repurchase program, shares		(691,563)
Balance, value at Jun. 30, 2011	5,023,107	858	7,683,804	(2,705,148)	41,013	2,580	293,480
Balance, shares at Jun. 30, 2011		858,163,737
Balance, value at Dec. 31, 2011	4,663,314	869	7,775,880	(3,155,222)	41,948	(161)
Balance, shares at Dec. 31, 2011		869,187,360
Net income (loss)	(48,001)	0	0	(48,193)		192
Unrealized gain/loss on investment securities	25,499	0	0	0	25,499	0
Reversal of unrealized (gain) loss to realized gain (loss) and impairment on securities	1,022	0	0	0	1,022	0
Unrealized gain/loss on derivatives	549	0	0	0	549	0
Distributions declared	(219,089)	0	0	(218,858)	0	(231)
Adjustment to redemption value for noncontrolling redeemable interest	0
Proceeds from distribution reinvestment plan, value	97,571	13	97,558	0	0	0
Proceeds from distribution reinvestment plan, shares		13,513,840
Share repurchase program, value	(24,185)	(3)	(24,182)	0	0	0
Share repurchase program, shares		(3,349,894)
Balance, value at Jun. 30, 2012	$ 4,496,680	$ 879	$ 7,849,256	$ (3,422,273)	$ 69,018	$ (200)
Balance, shares at Jun. 30, 2012		879,351,306