CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME/(LOSS) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net Income	$ 313,504	$ 302,709	$ 306,839
Other Comprehensive Income/(Loss):
Reclassification adjustment for MBS sales included in net income	(34,948)	(19,833)	(7,493)
Reclassification adjustment for other-than-temporary impairments included in net income	0	0	(1,200)
Unrealized (loss)/gain on derivative hedging instruments, net	(44,292)	47,614	51,363
Reclassification of unrealized loss on de-designated derivative hedging instruments	447	0	0
Other Comprehensive Income/(Loss)	16,758	(24,282)	820,680
Comprehensive Income before preferred stock dividends and issuance costs of redeemed preferred stock	330,262	278,427	1,127,519
Dividends declared on preferred stock	(15,000)	(13,750)	(8,160)
Issuance costs of redeemed preferred stock	0	(3,947)	0
Comprehensive Income Available to Common Stock and Participating Securities	315,262	260,730	1,119,359
Agency MBS
Other Comprehensive Income/(Loss):
Unrealized (loss)/gain on MBS and CRT securities, net	65,739	(186,568)	(7,820)
Non-Agency MBS
Other Comprehensive Income/(Loss):
Unrealized (loss)/gain on MBS and CRT securities, net	31,602	134,505	785,830
CRT securities
Other Comprehensive Income/(Loss):
Unrealized (loss)/gain on MBS and CRT securities, net	$ (1,790)	$ 0	$ 0