CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands		Total	Preferred Stock Par Value	Common Stock Par Value	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Cumulative Earnings	Cumulative Distributions to Stockholders	Preferred Class A	Preferred Class A Preferred Stock Par Value	Preferred Class A Additional Paid-in Capital
Beginning Balance at Dec. 31, 2013		$ 3,331,510	$ 0	$ 2,055	$ 3,613,458	$ 990,803	$ 1,063,822	$ (2,338,628)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		589,205					589,205	0
Other comprehensive income (loss)		55,877				55,877	0	0
Stock based compensation		953			953	0
Common dividends declared		(369,855)	0	0	0			(369,855)
Preferred dividends declared		0
Ending Balance at Dec. 31, 2014		3,607,690	0	2,055	3,614,411	1,046,680	1,653,027	(2,708,483)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		250,349					250,349	0
Cumulative effect of accounting change	[1]	(12,137)					(12,137)	0
Other comprehensive income (loss)		(272,889)				(272,889)
Stock based compensation		1,979		2	1,977
Repurchase of common stock		(250,000)		(180)	(249,820)
Common dividends declared		(378,804)					0	(378,804)
Preferred dividends declared		0
Ending Balance at Dec. 31, 2015		2,946,188	0	1,877	3,366,568	773,791	1,891,239	(3,087,287)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		551,943					551,943
Other comprehensive income (loss)		(55,685)				(55,685)
Stock based compensation		2,206		0	2,206
Common dividends declared		(458,735)						(458,735)
Preferred dividends declared		(2,449)						(2,449)
Issuance of preferred stock									$ 140,065	$ 58	$ 140,007
Ending Balance at Dec. 31, 2016		$ 3,123,533	$ 58	$ 1,877	$ 3,508,781	$ 718,106	$ 2,443,182	$ (3,548,471)

[1] Adoption of ASU No. 2014-13, Measuring the Financial Assets and the Financial Liabilities of a Consolidated Collateralized Financing Entity.