Consolidated Statements of Changes in Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Distributions in excess of Net Loss	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests
Balance, value at Dec. 31, 2013	$ 4,266,641	$ 909	$ 8,063,517	$ (3,870,649)	$ 71,128	$ 1,736
Balance, shares at Dec. 31, 2013		909,855,173
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income Loss Attributable To Company Inclusive Of Noncontrolling Interest Excluding Noncontrolling Redeemable Interests				139,971		8
Net income	139,979
Unrealized gain on investment securities	20,435				20,435
Unrealized (gain) loss on derivatives	(1,719)				(1,719)
Reclassification adjustment from AOCI on derivatives and securities	(14,573)				(14,573)
Distributions declared	(221,435)			(221,435)
Noncontrolling Interest, Increase from Subsidiary Equity Issuance						972
Stock Issued During Period, Shares, Dividend Reinvestment Plan		11,997,004
Stock Issued During Period, Value, Dividend Reinvestment Plan	83,259	$ 12	83,247
Share repurchase program, shares		(1,077,829)
Stock Repurchased and Retired During Period, Value	7,481	$ 1	7,480
Stock Repurchased During Period, Value	(396,330)	(61)	(396,269)
Balance, value at Jun. 30, 2014	3,869,748	$ 859	7,743,015	(3,952,113)	75,271	2,716
Balance, shares at Jun. 30, 2014		860,013,182
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock Repurchased During Period, Shares		(60,761,166)
Balance, value at Dec. 31, 2013	4,266,641	$ 909	8,063,517	(3,870,649)	71,128	1,736
Balance, shares at Dec. 31, 2013		909,855,173
Balance, value at Dec. 31, 2014	3,996,829	$ 861	7,755,471	(3,820,882)	57,599	3,780
Balance, shares at Dec. 31, 2014		861,824,777
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock Repurchased During Period, Shares		(60,761,166)
Net Income Loss Attributable To Company Inclusive Of Noncontrolling Interest Excluding Noncontrolling Redeemable Interests	67,896			67,888		8
Net income	67,896
Unrealized gain on investment securities	33,355				33,355
Unrealized (gain) loss on derivatives	595				595
Reclassification adjustment from AOCI on derivatives and securities	(20,682)				(20,682)
Distributions declared	(82,591)			(82,591)
Noncontrolling Interest, Increase from Subsidiary Equity Issuance	160					160
Share-based compensation expense, net of forfeitures	130		130
Stockholders' Equity Note, Spinoff Transaction	(1,694,234)		(1,690,411)			(3,823)
Balance, value at Jun. 30, 2015	$ 2,301,458	$ 861	$ 6,065,190	$ (3,835,585)	$ 70,867	$ 125
Balance, shares at Jun. 30, 2015		861,824,777