Schedule of Unobservable Inputs Used in Level 3 Valuation of Mortgage Loans Held for Investment (Details) - Level 3	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Minimum | Mortgage Loans Held for Investment in Securitization Trusts, at Fair Value
Fair Value Inputs Assets Quantitative Information [Line Items]
Discount rate	2.20%
Conditional refinance rate	0.00%
Default rate	0.00%
Loss severity	0.00%
Maximum | Mortgage Loans Held for Investment in Securitization Trusts, at Fair Value
Fair Value Inputs Assets Quantitative Information [Line Items]
Discount rate	3.60%
Conditional refinance rate	21.30%
Default rate	2.00%
Loss severity	22.90%
Weighted Average | Mortgage Loans Held for Investment in Securitization Trusts, at Fair Value
Fair Value Inputs Assets Quantitative Information [Line Items]
Discount rate	3.30%
Conditional refinance rate	16.40%
Default rate	0.50%
Loss severity	14.40%
Mortgage Held for Investment, at Fair Value | Minimum
Fair Value Inputs Assets Quantitative Information [Line Items]
Discount rate	3.00%	3.60%
Conditional refinance rate	13.60%	12.40%
Default rate	0.00%	0.00%
Loss severity	10.50%	10.20%
Mortgage Held for Investment, at Fair Value | Maximum
Fair Value Inputs Assets Quantitative Information [Line Items]
Discount rate	3.50%	3.90%
Conditional refinance rate	21.70%	19.30%
Default rate	2.10%	1.50%
Loss severity	22.20%	19.90%
Mortgage Held for Investment, at Fair Value | Weighted Average
Fair Value Inputs Assets Quantitative Information [Line Items]
Discount rate	3.30%	3.80%
Conditional refinance rate	16.40%	15.30%
Default rate	0.70%	0.40%
Loss severity	14.90%	13.80%