Mortgage Servicing Rights and Mortgage Servicing Activity Mortgage Servicing Rights Assumptions Details (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption [Line Items]
Assumption for Fair Value of Assets or Liabilities that relate to Transferor's Continuing Involvement, Prepayment Speed	14.62%
Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of 10 Percent Adverse Change in Prepayment Speed	$ 861
Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor Servicing Assets or Liabilities Impact of Twenty Five Percent Adverse Change in Prepayment Speed	2,052
Assumption for Fair Value of Assets or Liabilities that relate to Transferor's Continuing Involvement, Discount Rate	9.64%
Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor Servicing Assets or Liabilities Impact of Hundred Basis Point Adverse Change in Discount Rate	540
Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor Servicing Assets or Liabilities Impact of Two Hundred Basis Point Adverse Change in Discount Rate	$ 1,047
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Weighted Average Life	6 years 9 months 3 days