Servicing Rights - Key Assumptions and the Sensitivity of the Fair Value (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Servicing Assets at Fair Value [Line Items]
Aggregate portfolio principal balance	$ 683,117	$ 659,048
Base
MSR as a percentage of serviced loans	1.64%	1.81%
Mortgage servicing rights
Servicing Assets at Fair Value [Line Items]
Aggregate portfolio principal balance	$ 683,117	$ 659,048
Weighted average rate of note	3.62%	3.90%
Base
Constant prepayment rate	13.05%	10.61%
Average discount rate	7.75%	8.52%
Mortgage servicing rights, at fair value	$ 11,218	$ 11,920	$ 10,821	$ 7,305
MSR as a percentage of serviced loans	1.64%	1.81%
1.0% Adverse Rate Change
Constant prepayment rate	26.11%	26.25%
Discount rate	6.75%	7.52%
Fair value MSR	$ 7,455	$ 7,005
Percentage of MSR	1.09%	1.06%
2.0% Adverse Rate Change
Constant prepayment rate	38.97%	28.39%
Discount rate	5.75%	6.52%
Fair value MSR	$ 5,404	$ 6,625
Percentage of MSR	0.79%	1.01%