Loans - Amortized cost basis of loans on nonaccrual status (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
Interest income on loans on nonaccrual status	$ 0
Reversal of interest income upon placing loans on nonaccrual status	19
Loans on nonaccrual status	1,298	$ 1,189
Commercial real estate
Loans on nonaccrual status	77	108
Residential mortgage
Loans on nonaccrual status	320	156
Equity lines
Loans on nonaccrual status	9
Consumer finance \| Automobiles
Loans on nonaccrual status	$ 892	842
Consumer finance \| Marine and recreational vehicles
Loans on nonaccrual status		$ 83

Amortized cost of financing receivable on nonaccrual status. Excludes net investment in lease.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-16

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph (a)
-Subparagraph (3)
-Publisher SEC

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph (a)
-Subparagraph (2)
-Publisher SEC

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481962/310-10-50-7

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant