Residential Mortgage Loans Held in Securitization Trusts (Net) and Real Estate Owned - Delinquencies in Portfolio of Residential Mortgage Loans Held in Securitization Trusts (Details) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2017 USD ($) loan	Dec. 31, 2016 USD ($) loan
Financing Receivable, Recorded Investment, Past Due [Line Items]
Real estate owned through foreclosure, Number of Delinquent Loans \| loan	2	1
Real estate owned through foreclosure, Total Unpaid Principal \| $	$ 1,045	$ 268
Real estate owned through foreclosure, % of Loan Portfolio	1.24%	0.27%
30 - 60
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of Delinquent Loans \| loan	0	1
Total Unpaid Principal \| $	$ 0	$ 247
% of Loan Portfolio	0.00%	0.25%
61 - 90
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of Delinquent Loans \| loan	0	0
Total Unpaid Principal \| $	$ 0	$ 0
% of Loan Portfolio	0.00%	0.00%
90
Financing Receivable, Recorded Investment, Past Due [Line Items]
Number of Delinquent Loans \| loan	24	30
Total Unpaid Principal \| $	$ 15,410	$ 18,416
% of Loan Portfolio	18.32%	18.68%

Financing Receivable, Recorded Investment Past Due, Real Estate Owned Through Foreclosure.

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- Definition

The aggregate number of delinquent loans.

+ References

No definition available.

+ Details

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- Definition

Number of delinquent loans through foreclosure.

+ References

No definition available.

+ Details

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- Definition

Percent of loan portfolio.

+ References

No definition available.

+ Details

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- Definition

The aggregate percentage of the loan portfolio through foreclosure.

+ References

No definition available.

+ Details

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- Definition

Recorded Investment in financing receivables that are past due at the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7A
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953401-111524

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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