Mortgage Servicing Rights (Amortization method rollforward) (Details 3) - Mortgage Servicing Rights - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Change in Carrying Value of Mortgage Servicing Rights Accounted for Under the Amortization Method, Net of a Valuation Allowance
Balance at beginning of Year	$ 23,020	$ 23,168	$ 22,008
Servicing Rights that Resulted From Asset Transfers	4,485	2,470	3,976
Amortization	(3,609)	(2,618)	(2,816)
Balance at end of Year	23,896	23,020	23,168
Fair Value:
Balance at Beginning of Year	29,218	26,716	25,148
Balance at End of Year	$ 25,714	$ 29,218	$ 26,716