Mortgage Servicing Rights and Mortgage Servicing Activity (Changes in the Carrying Amount of Mortgage Servicing Rights) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
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	$ 1,345		$ 1,345
Mortage Servicing Rights Amortized Value [Roll Forward]
Mortgage Servicing Rights Beginning of Period	20,635	$ 22,150	22,011	$ 22,760	$ 22,760
Mortgage Servicing Rights Additions	53	1,035	586	2,242
Amortization of Mortgage Servicing Rights (MSRs)	(921)	(996)	(2,830)	(2,813)
Mortgage Servicing Rights, End of Period	19,767	22,189	19,767	22,189	22,011
Mortage Servicing Rights Valuation Rollforward [Roll Forward]
Mortgage Servicing rights Valuation Allowance Beginning of Period	490	562	955	282	282
Mortgage Servicing Rights (MSR) Impairment Recovery/(Additions)	(60)	(57)	(405)	223	(700)
Mortgage Servicing rights Valuation Allowance, End of Period	550	505	550	505	955
Mortgage Servicing Rights Net Carrying balance	19,217	21,684	19,217	21,684	21,100
Fair Value of Mortgage Servicing Rights	19,556	22,229	19,556	22,229	21,228
Level 3
Mortage Servicing Rights Valuation Rollforward [Roll Forward]
Fair Value of Mortgage Servicing Rights	19,556	22,229	19,556	22,229	$ 21,228
Residential Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Servicing Asset	$ 2,400,000	$ 2,600,000	$ 2,400,000	$ 2,600,000