Mortgage Servicing Rights (Economic Assumptions) (Details) - $ / loans	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Servicing Asset Key Economic Assumptions [Line Items]
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Prepayment Speed	10.41%	14.25%
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Cost to Service Loans	56.61	56.02
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	7.05%	7.20%
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	9.05%	9.20%