CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Pledged Securities	$ 690,592	$ 639,683
Distressed residential mortgage loans, net, held in securitization trusts	195,347	114,214
Assets of consolidated VEIs	7,330,872	7,412,093
Liabilities of consolidated VIEs	$ 6,902,536	$ 7,077,175
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	200,000,000	200,000,000
Preferred stock, shares issued (in shares)	6,600,000	6,600,000
Preferred stock, shares outstanding (in shares)	6,600,000	6,600,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	400,000,000	400,000,000
Common stock, shares issued (in shares)	111,474,521	109,401,721
Common stock, shares outstanding (in shares)	111,474,521	109,401,721
Series B Preferred Stock
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, liquidation preference (in dollars per share)	$ 25.00	$ 25
Preferred stock, shares authorized (in shares)	6,000,000	6,000,000
Preferred stock, shares issued (in shares)	3,000,000	3,000,000
Preferred stock, shares outstanding (in shares)	3,000,000	3,000,000
Preferred stock, dividend rate (as a percent)	7.75%	7.75%
Series C Preferred Stock
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, liquidation preference (in dollars per share)	$ 25	$ 25
Preferred stock, shares authorized (in shares)	4,140,000	4,140,000
Preferred stock, shares issued (in shares)	3,600,000	3,600,000
Preferred stock, shares outstanding (in shares)	3,600,000	3,600,000
Preferred stock, dividend rate (as a percent)	7.875%	7.875%
Available-for-sale Securities
Investment securities held in securitization	$ 43,897	$ 40,734