Mortgage Servicing Rights - Estimated Future Amortization Expenses (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Other Intangible Assets
Unpaid principal amount of consumer loans serviced for others	$ 1,400,000		$ 1,400,000
Contractually specified fees, late charges, and ancillary fees	900	$ 1,000
Amortization of mortgage servicing rights	280	$ 736
Details of MSRs
Gross carrying amount	69,290		69,273
Less: accumulated amortization	62,991		62,711
Net carrying value	6,299		$ 6,562
Mortgage servicing assets
Estimated future amortization expenses for MSRs over the next five years
Under one year	910
One to two years	809
Two to three years	718
Three to four years	634
Four to five years	$ 560

Principal amount of transferred financial assets in which the transferor has continuing involvement with the assets underlying the transaction. Continuing involvement includes, but is not limited to, servicing, recourse, and restrictions on transferor's interests in transferred financial assets.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of contractually specified servicing fee, late fee, and ancillary fee recognized as income for servicing asset and servicing liability.

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-Publisher FASB
-Name Accounting Standards Codification
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Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount of amortization of contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

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-Name Accounting Standards Codification
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