CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME/(LOSS) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Net income	$ 79,935,000	$ 78,950,000	$ 157,995,000	$ 157,020,000
Other Comprehensive Income/(Loss):
Reclassification adjustment for MBS sales included in net income	(5,656,000)	(8,688,000)	(15,602,000)	(19,651,000)
Reclassification adjustment for other-than-temporary impairments included in net income	(618,000)	0	(1,032,000)	0
Derivative hedging instrument fair value changes, net	(1,017,000)	(13,230,000)	10,880,000	(62,572,000)
Other Comprehensive Income/(Loss)	37,719,000	83,316,000	58,700,000	(22,125,000)
Comprehensive income before preferred stock dividends	117,654,000	162,266,000	216,695,000	134,895,000
Dividends declared on preferred stock	(3,750,000)	(3,750,000)	(7,500,000)	(7,500,000)
Comprehensive Income Available to Common Stock and Participating Securities	113,904,000	158,516,000	209,195,000	127,395,000
Agency MBS
Other Comprehensive Income/(Loss):
Unrealized (loss)/gain, net	(11,157,000)	11,572,000	(19,209,000)	24,798,000
Non-Agency MBS
Other Comprehensive Income/(Loss):
Unrealized (loss)/gain, net	$ 56,167,000	$ 93,662,000	$ 83,663,000	$ 35,300,000