Mortgage Servicing Rights - Summary of Carrying Value Under the Amortization Method (Details) - Mortgage Servicing Rights - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Mortgage Servicing Rights Accounted for Under the Amortization Method (Rollforward)
Balance at Beginning of Year	$ 18,694	$ 23,896	$ 23,020
Servicing Rights that Resulted From Asset Transfers	4,921	3,592	4,485
Amortization	(4,227)	(4,902)	(3,609)
Valuation Allowance Recovery (Provision)	2,063	(3,892)
Balance at End of Year	21,451	18,694	23,896
Valuation Allowance:
Balance at Beginning of Year	(3,892)
Valuation Allowance Recovery (Provision)	2,063	(3,892)
Balance at End of Year	(1,829)	(3,892)
Fair Value:
Balance	$ 21,451	$ 18,694	$ 25,714	$ 29,218