Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Distributions in excess of accumulated net income	Accumulated Comprehensive Income
Balance beginning of period (in shares) at Dec. 31, 2016		773,304,997
Balance beginning of period at Dec. 31, 2016	$ 1,949,528	$ 773	$ 5,676,639	$ (3,786,943)	$ 59,059
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	61,793			61,793
Unrealized gain on investment securities	(11,734)				(11,734)
Unrealized gain on derivatives	1,183				1,183
Reclassification for amounts recognized in net income	(46,563)				(46,563)
Distributions declared	(53,758)			(53,758)
Stock-based compensation, net (in shares)		988,200
Stock-based compensation, net	3,344		3,344
Refund of excess funds associated with 2016 tender offer	1,929		1,929
Balance end of period (in shares) at Dec. 31, 2017		774,293,197
Balance end of period at Dec. 31, 2017	1,905,722	$ 773	5,681,912	(3,778,908)	1,945
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	83,849			83,849
Unrealized gain on investment securities	0
Unrealized gain on derivatives	923				923
Reclassification for amounts recognized in net income	(956)
Distributions declared	(53,782)			(53,782)
Reclassification to interest expense, net	(956)				(956)
Stock-based compensation, net (in shares)		825,081
Stock-based compensation, net	2,293	$ 1	2,292
Repurchase of common stock (in shares)		(46,559,289)
Repurchase of common stock	(98,491)	$ (45)	(98,446)
Balance end of period (in shares) at Dec. 31, 2018		728,558,989
Balance end of period at Dec. 31, 2018	1,852,314	$ 729	5,585,758	(3,735,810)	1,637
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	38,399			38,399
Unrealized gain on investment securities	0
Unrealized gain on derivatives	816				816
Reclassification for amounts recognized in net income	(1,396)
Distributions declared	(53,473)			(53,473)
Reclassification to interest expense, net	(1,396)				(1,396)
Stock-based compensation, net (in shares)		766,500
Stock-based compensation, net	3,325	$ 1	3,324
Repurchase of common stock (in shares)		(8,517,605)
Repurchase of common stock	(20,384)	$ (9)	(20,375)
Balance end of period (in shares) at Dec. 31, 2019		720,807,884
Balance end of period at Dec. 31, 2019	$ 1,819,601	$ 721	$ 5,568,707	$ (3,750,884)	$ 1,057