Loans - Summary of Purchased Loans Pools (Details) $ in Thousands		9 Months Ended		12 Months Ended
		Sep. 30, 2024 USD ($) Loan		Dec. 31, 2023 USD ($) Segment
Accounts Notes And Loans Receivable [Line Items]
Original Balance		$ 170,350		$ 179,800
Current Balance		75,440		87,400
Unamortized Premium/ (Discount)		$ (6,133)		$ (6,504)
Number of Loans		2,790		3,093
Cumulative net charge-offs		$ 2,560		$ 69
Commercial and Industrial Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Original Balance		6,800		6,800
Current Balance		1,300		1,600
Unamortized Premium/ (Discount)		$ 0		$ 0
Number of Loans		19		20
Commercial and Industrial Loans [Member] | Minimum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		2 years		2 years
Commercial and Industrial Loans [Member] | Maximum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		5 years		6 years
Home Equity Lines of Credit [Member]
Accounts Notes And Loans Receivable [Line Items]
Original Balance		$ 21,900		$ 21,900
Current Balance		3,600		4,500
Unamortized Premium/ (Discount)		$ 24		$ 108
Number of Loans		101		159
Cumulative net charge-offs		$ 51
Home Equity Lines of Credit [Member] | Minimum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		4 years		1 year
Home Equity Lines of Credit [Member] | Maximum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		25 years		26 years
Unsecured Consumer Loan Pool 2 [Member]
Accounts Notes And Loans Receivable [Line Items]
Original Balance		$ 26,600		$ 26,600
Current Balance		40		500
Unamortized Premium/ (Discount)		$ 0		$ 2
Number of Loans		71		167
Unsecured Consumer Loan Pool 2 [Member] | Minimum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		0 years		0 years
Unsecured Consumer Loan Pool 2 [Member] | Maximum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		2 years		2 years
Residential Real Estate Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Original Balance		$ 4,300		$ 4,300
Current Balance		4,200		4,500
Unamortized Premium/ (Discount)		$ 280		$ 284
Number of Loans		54		56
Residential Real Estate Loans [Member] | Minimum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		16 years		17 years
Residential Real Estate Loans [Member] | Maximum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		25 years		25 years
Unsecured Consumer Loan Pool 1 [Member]
Accounts Notes And Loans Receivable [Line Items]
Original Balance		$ 5,400		$ 5,400
Current Balance		600		1,000
Unamortized Premium/ (Discount)		$ 0		$ 0
Number of Loans		41		46
Unsecured Consumer Loan Pool 1 [Member] | Minimum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		1 year		1 year
Unsecured Consumer Loan Pool 1 [Member] | Maximum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		3 years		3 years
Unsecured Consumer Installment Loans Pool 3 [Member]
Accounts Notes And Loans Receivable [Line Items]
Original Balance		$ 10,300	[1]	$ 10,300
Current Balance		200	[1]	500
Unamortized Premium/ (Discount)		$ 6	[1]	$ 17
Number of Loans		92	[1]	158
Cumulative net charge-offs		$ 37	[1]	$ 69
Unsecured Consumer Installment Loans Pool 3 [Member] | Minimum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		0 years	[1]	0 years
Unsecured Consumer Installment Loans Pool 3 [Member] | Maximum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		9 years	[1]	9 years
Secured Consumer Installment Loans Pool 4 [Member]
Accounts Notes And Loans Receivable [Line Items]
Original Balance		$ 14,500		$ 14,500
Current Balance		9,500		10,600
Unamortized Premium/ (Discount)		$ (1,308)		$ (1,252)
Number of Loans		480		499
Cumulative net charge-offs		$ 5
Secured Consumer Installment Loans Pool 4 [Member] | Minimum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		21 years		21 years
Secured Consumer Installment Loans Pool 4 [Member] | Maximum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		25 years		25 years
Unsecured Consumer Loan Pool 5 [Member]
Accounts Notes And Loans Receivable [Line Items]
Original Balance		$ 24,400	[2]	$ 24,400
Current Balance		13,300	[2]	15,600
Unamortized Premium/ (Discount)		$ (357)	[2]	$ (450)
Number of Loans		610	[2]	644
Cumulative net charge-offs	[2]	$ 1,001
Unsecured Consumer Loan Pool 5 [Member] | Minimum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		6 years	[2]	7 years
Unsecured Consumer Loan Pool 5 [Member] | Maximum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		21 years	[2]	22 years
Revolving Commercial Line of Credit 1 [Member]
Accounts Notes And Loans Receivable [Line Items]
Original Balance		$ 11,600		$ 11,600
Current Balance		8,600		12,400
Unamortized Premium/ (Discount)		$ 0		$ 2
Number of Loans		1		1
Revolving Commercial Line of Credit 1 [Member] | Minimum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		0 years		0 years
Revolving Commercial Line of Credit 1 [Member] | Maximum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		1 year		1 year
Secured Consumer Installment Loans [Member]
Accounts Notes And Loans Receivable [Line Items]
Original Balance		$ 21,300		$ 21,300
Current Balance		16,800		18,000
Unamortized Premium/ (Discount)		$ (2,687)		$ (2,923)
Number of Loans		808		821
Cumulative net charge-offs		$ 290
Secured Consumer Installment Loans [Member] | Minimum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		17 years		17 years
Secured Consumer Installment Loans [Member] | Maximum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		24 years		24 years
Revolving Commercial Line of Credit 2 [Member]
Accounts Notes And Loans Receivable [Line Items]
Original Balance				$ 10,500
Current Balance				0
Unamortized Premium/ (Discount)				$ 0
Number of Loans | Segment				0
Unsecured Consumer Loan Pool 6 [Member]
Accounts Notes And Loans Receivable [Line Items]
Original Balance		$ 22,200	[2]	$ 22,200
Current Balance		16,200	[2]	18,200
Unamortized Premium/ (Discount)		$ (2,125)	[2]	$ (2,292)
Number of Loans		512	[2]	522
Cumulative net charge-offs	[2]	$ 1,176
Unsecured Consumer Loan Pool 6 [Member] | Minimum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		7 years	[2]	7 years
Unsecured Consumer Loan Pool 6 [Member] | Maximum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		24 years	[2]	24 years
Revolving Commercial Line of Credit 1 [Member]
Accounts Notes And Loans Receivable [Line Items]
Original Balance		$ 1,050
Current Balance		1,100
Unamortized Premium/ (Discount)		$ 34
Number of Loans | Loan		1
Revolving Commercial Line of Credit 1 [Member] | Minimum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		0 years
Revolving Commercial Line of Credit 1 [Member] | Maximum [Member]
Accounts Notes And Loans Receivable [Line Items]
Maturity Range		1 year

[1] In December 2023, the primary servicer for a purchased pool of consumer installment loans declared bankruptcy and the Bank placed the loans within the serviced pool on nonaccrual status pending the release of collected funds by the U.S. Bankruptcy court of jurisdiction. The current balance reflects anticipated principal payments that are expected to be received after the bankruptcy proceedings are finalized and the remaining amount expected to be collected from the pool’s underlying borrowers. At September 30, 2024, the Bank has recorded a total receivable of $347,000 related to the remaining unpaid portion of the original loan pool, of which $124,000 has currently been collected by the servicer from underlying borrowers and is being held in a segregated account by the Bankruptcy Court and approximately $223,000 remains due from borrowers under the scheduled repayment terms of their original loan agreements. The Bank’s management expects to ultimately collect substantially all of these funds and does not consider the loans in this pool to be impaired at September 30, 2024.

[2] On December 7, 2023, the Bank settled two pay-fixed interest rate swap derivative contracts, previously established with an unaffiliated third party and designated as fair value interest rate hedges. The hedging swap contracts were related to two purchased consumer installment loan pools comprised of loans secured by residential home solar power infrastructure. These contracts were entered into on February 13, 2021 (notional amount of $12.2 million) and December 8, 2021 (notional amount of $8.5 million). The Bank realized gains related to the settlement of these two hedging contracts were $117,000 and $694,000, respectively. These gains on the extinguishment of the hedging swap contracts are reported as a reduction of the carrying value of the hedged loan pools and will be recognized as an enhancement to the reported yield on those loan pools over the original contractual life of the hedging swap contracts. The unamortized portion of these gains totaled $729,000 at September 30, 2024.