Servicing Rights - Key Assumptions and the Sensitivity of the Fair Value (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Servicing Assets at Fair Value [Line Items]
Aggregate portfolio principal balance	$ 655,183	$ 659,048
Base
Servicing rights	$ 10,721	$ 11,920
Percentage of MSR (percent)	1.64%	1.81%
Mortgage servicing rights
Servicing Assets at Fair Value [Line Items]
Aggregate portfolio principal balance	$ 655,183	$ 659,048
Weighted average rate of note (percent)	3.80%	3.90%
Base
Constant prepayment rate (percent)	14.30%	10.61%
Discount rate (percent)	7.75%	8.52%
Servicing rights	$ 10,721	$ 11,920	$ 11,653	$ 10,836	$ 11,254	$ 10,821
Percentage of MSR (percent)	1.64%	1.81%
1.0% Adverse Rate Change
Constant prepayment rate (percent)	40.94%	26.25%
Discount rate (percent)	6.75%	7.52%
Fair value MSR	$ 4,304	$ 7,005
Percentage of MSR (percent)	0.66%	1.06%
2.0% Adverse Rate Change
Constant prepayment rate (percent)	50.36%	28.39%
Discount rate (percent)	5.75%	6.52%
Fair value MSR	$ 3,376	$ 6,625
Percentage of MSR (percent)	0.52%	1.01%