Loan Servicing Activity of MSRs and the related valuation allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Servicing Asset at Amortized Cost, Balance [Roll Forward]
Servicing Asset at Amortized Cost, Beginning Balance	$ 10,178	$ 9,688	$ 9,266
Servicing Asset at Amortized Cost, Additions	2,355	1,591	1,941
Servicing Asset at Amortized Cost, Amortization	1,870	1,499	1,624
Servicing Asset at Amortized Cost, Increase (Decrease) for Valuation Allowance Adjustment	(593)	398	105
Servicing Asset at Amortized Cost, Ending Balance	10,070	10,178	9,688
Valuation Allowance for Impairment of Recognized Servicing Assets [Roll Forward]
Valuation Allowance for Impairment of Recognized Servicing Assets, Balance, Beginning Balance	232	630	735
Valuation Allowance for Impairment of Recognized Servicing Assets, Additions (Deductions) for Expenses (Recoveries)	593	(398)	(105)
Valuation Allowance for Impairment of Recognized Servicing Assets, Balance, Ending Balance	$ 825	$ 232	$ 630