CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
MSR Related Assets, pledged as collateral	$ 412,674,000	$ 226,780,000
Residential whole loans, at carrying value, pledged as collateral	347,906,000	427,880,000
Residential whole loans, at fair value, pledged as collateral	$ 903,494,000	$ 734,331,000
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	$ 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	396,939,000	371,854,000
Common stock, shares outstanding	396,939,000	371,854,000
Senior Notes
Stated interest rate	8.00%	8.00%
Agency MBS
Securities, at fair value, pledged as collateral	$ 2,911,353,000	$ 3,540,401,000
Non-Agency MBS
Securities, at fair value, pledged as collateral	2,853,891,000	4,751,419,000
CRT securities
Securities, at fair value, pledged as collateral	$ 530,833,000	$ 357,488,000