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Mortgage Servicing Rights (Economic Assumptions) (Details) - $ / loans | 3 Months Ended | 12 Months Ended
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Mar. 31, 2016 | Dec. 31, 2015
Servicing Asset Key Economic Assumptions [Line Items] |  |
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Prepayment Speed | 13.32% | 11.01%
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Cost to Service Loans | 62.75 | 56.61
Conventional fixed loans |  |
Servicing Asset Key Economic Assumptions [Line Items] |  |
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Discount Rate | 8.77% | 9.31%
All loans excluding conventional fixed loans |  |
Servicing Asset Key Economic Assumptions [Line Items] |  |
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Discount Rate | 9.77% | 10.31%

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- Definition [Line Items] for The key economic assumptions used to value servicing assets. + References No definition available. + Details
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- Definition Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Cost to Service Loans + References No definition available. + Details
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- Definition Discount rate used to estimate the fair value of servicing assets and servicing liabilities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 50 -Section 50 -Paragraph 2 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=56950315&loc=d3e122596-111746 + Details
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- Definition Estimated rate of prepayments of principal on servicing assets and servicing liabilities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 50 -Section 50 -Paragraph 2 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=56950315&loc=d3e122596-111746 + Details
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