CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock Par Value	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Cumulative Earnings	Cumulative Distributions to Stockholders	Series A Preferred Stock Par Value	Series A Preferred Stock Par Value Preferred Stock	Series B Preferred Stock Par Value Preferred Stock
Beginning Balance at Dec. 31, 2015	$ 2,946,188	$ 1,877	$ 3,366,568	$ 773,791	$ 1,891,239	$ (3,087,287)		$ 0	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	83,098				83,098	0
Other comprehensive income (loss)	68,474			68,474
Stock based compensation	102	0	102
Repurchase of common stock	0	0	0
Common dividends declared	(184,227)				0	(184,227)
Preferred dividends declared	0
Ending Balance at Mar. 31, 2016	2,913,635	1,877	3,366,670	842,265	1,974,337	(3,271,514)		0	0
Beginning Balance at Dec. 31, 2016	3,123,533	1,877	3,508,779	718,106	2,443,184	(3,548,471)		58	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	162,807				162,807
Other comprehensive income (loss)	9,605			9,605
Stock based compensation	1,120	1	1,119
Common dividends declared	(94,123)					(94,123)
Preferred dividends declared	(5,283)					(5,283)	$ (3,000)
Issuance of preferred stock							$ 314,429	0	130
Ending Balance at Mar. 31, 2017	$ 3,512,088	$ 1,878	$ 3,824,197	$ 727,711	$ 2,605,991	$ (3,647,877)		$ 58	$ 130