Residential Mortgage Loans Held in Securitization Trusts (Net) and Real Estate Owned - Loans in Delinquency (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) loan	Dec. 31, 2014 USD ($) loan
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of Delinquent Loans, Real estate owned through foreclosure | loan	3	6
Total Unpaid Principal, Real estate owned through foreclosure | $	$ 574	$ 2,100
% of Loan Portfolio, Real estate owned through foreclosure	0.47%	1.36%
30 - 60
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of Delinquent Loans | loan	3	4
Total Unpaid Principal | $	$ 825	$ 1,522
% of Loan Portfolio	0.67%	0.99%
61 - 90
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of Delinquent Loans | loan	2	0
Total Unpaid Principal | $	$ 1,763	$ 0
% of Loan Portfolio	1.43%	0.00%
90
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of Delinquent Loans | loan	26	29
Total Unpaid Principal | $	$ 15,365	$ 16,997
% of Loan Portfolio	12.48%	11.01%