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, 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]
Net Income Loss Attributable To Company Inclusive Of Noncontrolling Interest Excluding Noncontrolling Redeemable Interests	5,833			5,825		8
Unrealized gain on investment securities	51,204				51,204
Unrealized (gain) loss on derivatives	(360)				(360)
Reclassification adjustment from AOCI on derivatives and securities	(2,974)				(2,974)
Distributions declared	(54,585)			(54,585)
Noncontrolling Interest, Increase from Subsidiary Equity Issuance						160
Balance, value at Mar. 31, 2015	2,301,873	$ 861	6,065,060	(3,869,642)	105,469	125
Balance, shares at Mar. 31, 2015		861,824,777
Balance, value at Dec. 31, 2015	2,148,703	$ 862	6,066,583	(3,956,032)	37,290
Balance, shares at Dec. 31, 2015		862,205,672
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income Loss Attributable To Company Inclusive Of Noncontrolling Interest Excluding Noncontrolling Redeemable Interests	25,408			25,408
Unrealized gain on investment securities	5,212				5,212
Unrealized (gain) loss on derivatives	(4,321)				(4,321)
Reclassification adjustment from AOCI on derivatives and securities	(2)				(2)
Distributions declared	(28,023)			(28,023)
Share-based compensation expense, net of forfeitures	263		263
Stockholders' Equity Note, Spinoff Transaction	(1,694,234)		(1,690,411)			$ (3,823)
Balance, value at Mar. 31, 2016	$ 2,147,240	$ 862	$ 6,066,846	$ (3,958,647)	$ 38,179
Balance, shares at Mar. 31, 2016		862,205,672