Mortgage Servicing Rights (Amortization method rollforward) (Details 3) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Valuation Allowance for Impairment of Mortgage Servicing Rights Accounted for under the Amortization Method [Roll Forward]
Balance at End of Period	$ (53)		$ (53)
Mortgage Servicing Rights
Mortgage Servicing Rights Accounted for Under the Amortization Method {Rollforward)
Balance at Beginning of Period	22,705	$ 20,753	22,008	$ 21,032
Servicing Rights that Resulted From Asset Transfers	961	329	2,276	771
Amortization	(690)	(677)	(1,308)	(1,313)
Valuation Allowance Provision	(53)	(2,593)	(53)	(2,678)
Balance at End of Period	22,923	17,812	22,923	17,812
Valuation Allowance for Impairment of Mortgage Servicing Rights Accounted for under the Amortization Method [Roll Forward]
Balance at Beginning of Period	0	(106)	0	(21)
Valuation Allowance Provision	(53)	(2,593)	(53)	(2,678)
Balance at End of Period	(53)	(2,699)	(53)	(2,699)
Fair Value of Mortgage Servicing Rights Accounted for Under the Amortization Method
Beginning of Period	25,946	20,841	25,148	24,804
End of Period	$ 25,479	$ 17,812	$ 25,479	$ 17,812