Loans - Changes in Allowances for Credit Losses (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at the beginning of year	$ 24,961	$ 28,073
Provision increase (decrease)	4,425	2,670
Recoveries of previous charge-offs	1,657	1,413
Charge-offs, by origination year		(6,947)
Other	172	(248)
Allowances for expected credit losses at end of year	25,759	24,961
2023	(4)
2022	(52)
2021	(31)
2020	(33)
2019	(2)
Prior	(3,732)
Overdrafts and credit cards	(1,602)
Commercial loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at the beginning of year	12,143	11,126
Provision increase (decrease)	570	2,378
Recoveries of previous charge-offs	70	1
Charge-offs, by origination year		(1,314)
Other	5	(48)
Allowances for expected credit losses at end of year	11,248	12,143
2023	0
2022	0
2021	0
2020	0
2019	0
Prior	(1,474)
Overdrafts and credit cards	(66)
Commercial real estate loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at the beginning of year	884	1,168
Provision increase (decrease)	566	(285)
Recoveries of previous charge-offs	0	0
Charge-offs, by origination year		0
Other	(1)	1
Allowances for expected credit losses at end of year	1,441	884
2023	0
2022	0
2021	0
2020	0
2019	0
Prior	(8)
Overdrafts and credit cards	0
Consumer loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at the beginning of year	2,696	3,020
Provision increase (decrease)	1,223	1,252
Recoveries of previous charge-offs	975	1,150
Charge-offs, by origination year		(2,721)
Other	(18)	(5)
Allowances for expected credit losses at end of year	3,096	2,696
2023	(4)
2022	(52)
2021	(31)
2020	(33)
2019	(2)
Prior	(122)
Overdrafts and credit cards	(1,536)
Residential mortgage loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at the beginning of year	9,238	12,759
Provision increase (decrease)	2,066	(675)
Recoveries of previous charge-offs	612	262
Charge-offs, by origination year		(2,912)
Other	186	(196)
Allowances for expected credit losses at end of year	9,974	$ 9,238
2023
2022	0
2021	0
2020	0
2019	0
Prior	(2,128)
Overdrafts and credit cards	$ 0

Financing Receivable, Excluding Accrued Interest, Allowance For Credit Losses, Other Adjustments

No definition available.

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- Definition

Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479344/326-20-45-1

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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- Definition

Amount, excluding accrued interest, of increase in allowance for credit loss on financing receivable from recovery. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-13

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- Definition

Amount, excluding accrued interest, of decrease in allowance for credit loss on financing receivable from writeoff. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-6

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- Definition

Amount, excluding accrued interest, of credit loss expense (reversal of expense) on financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-13

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- Definition

Amount, excluding accrued interest, of writeoff of financing receivable originated more than five years before current fiscal year. Excludes net investment in lease.

+ References

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Amount, excluding accrued interest, of writeoff of financing receivable originated four years before current fiscal year. Excludes net investment in lease.

+ References

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Amount, excluding accrued interest, of writeoff of financing receivable originated three years before current fiscal year. Excludes net investment in lease.

+ References

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- Definition

Amount, excluding accrued interest, of writeoff of financing receivable originated in current fiscal year. Excludes net investment in lease.

+ References

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- Definition

Amount, excluding accrued interest, of writeoff of financing receivable originated two years before current fiscal year. Excludes net investment in lease.

+ References

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Amount, excluding accrued interest, of writeoff of financing receivable originated in fiscal year before current fiscal year. Excludes net investment in lease.

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- Definition

Amount of writeoff of financing receivable that can be withdrawn, repaid, and redrawn.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 79
-Publisher FASB
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