CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME/(LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net income	$ 322,393	$ 312,668	$ 313,226
Other Comprehensive Income/(Loss):
Reclassification adjustment for MBS sales included in net income	(38,707)	(36,922)	(37,207)
Reclassification adjustment for other-than-temporary impairments included in net income	(1,032)	(485)	(705)
Derivative hedging instrument fair value changes, net	35,297	22,678	(10,337)
Cumulative effect adjustment on adoption of revised accounting standard for repurchase agreement financing	0	0	4,537
Other Comprehensive Income/(Loss)	35,542	57,831	(238,602)
Comprehensive income before preferred stock dividends	357,935	370,499	74,624
Dividends declared on preferred stock	(15,000)	(15,000)	(15,000)
Comprehensive Income Available to Common Stock and Participating Securities	342,935	355,499	59,624
Agency MBS
Other Comprehensive Income/(Loss):
Unrealized (loss)/gain on MBS, net	(39,158)	(9,322)	(51,332)
Non-Agency MBS
Other Comprehensive Income/(Loss):
Unrealized (loss)/gain on MBS, net	$ 79,142	$ 81,882	$ (143,558)