Mortgage Servicing Rights - Estimated Future Amortization Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Other Intangible Assets
Unpaid principal amount of consumer loans serviced for others	$ 1,500,000		$ 1,500,000		$ 1,700,000
Contractually specified fees, late charges, and ancillary fees	900	$ 1,100	2,900	$ 3,700
Amortization of mortgage servicing rights	333	$ 1,001	1,587	$ 2,830
Details of MSRs
Gross carrying amount	69,254		69,254		69,103
Less: accumulated amortization	62,388		62,388		60,801
Net carrying value	6,866		6,866		$ 8,302
Mortgage servicing assets
Estimated future amortization expenses for MSRs over the next five years
Under one year	1,038		1,038
One to two years	912		912
Two to three years	800		800
Three to four years	699		699
Four to five years	$ 611		$ 611