CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Pledged securities	$ 639,683	$ 702,684
Accrued expenses and other liabilities, related parties	$ 1,745	$ 6,317
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)	3,000,000	3,000,000
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)	109,401,721	105,094,565
Common stock, shares outstanding (in shares)	109,401,721	105,094,565
Assets of consolidated VIEs	$ 7,413,082	$ 8,847,078
Liabilities of consolidated VIEs	$ 7,078,162	$ 8,457,034
Series B Preferred Stock
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, dividend rate (as a percent)	7.75%	7.75%
Preferred stock, liquidation preference (in dollars per share)	$ 25	$ 25
Preferred stock, shares authorized (in shares)	6,000,000	3,450,000
Preferred stock, shares issued (in shares)	3,000,000	3,000,000
Preferred stock, shares outstanding (in shares)	3,000,000	3,000,000
Series C Preferred Stock
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0
Preferred stock, dividend rate (as a percent)	7.875%	0.00%
Preferred stock, liquidation preference (in dollars per share)	$ 25	$ 0
Preferred stock, shares authorized (in shares)	4,140,000	0
Preferred stock, shares issued (in shares)	3,600,000	0
Preferred stock, shares outstanding (in shares)	3,600,000	0