CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Residential whole loans, at carrying value, pledged as collateral (in dollars)	$ 273,419,000	$ 93,692,000
Residential whole loans, at fair value, pledged as collateral (in dollars)	$ 618,416,000	$ 585,971,000
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	8,050,000	8,050,000
Preferred stock, dividend rate	7.50%	7.50%
Preferred stock, shares issued	8,000,000	8,000,000
Preferred stock, shares outstanding	8,000,000	8,000,000
Preferred stock, aggregate liquidation preference (in dollars)	$ 200,000,000	$ 200,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	886,950,000	886,950,000
Common stock, shares issued	371,083,000	370,584,000
Common stock, shares outstanding	371,083,000	370,584,000
Senior Notes
Stated interest rate	8.00%	8.00%
Agency MBS
Securities, at fair value, pledged as collateral	$ 3,783,913,000	$ 4,532,094,000
Non-Agency MBS
Securities, at fair value, pledged as collateral	4,882,017,000	4,874,372,000
CRT securities
Securities, at fair value, pledged as collateral	$ 320,852,000	$ 170,352,000