Loans and Allowance for Credit Losses - Narrative (Details)	12 Months Ended
Dec. 31, 2022 USD ($) loan commitment	Dec. 31, 2021 USD ($) loan	Dec. 31, 2020 USD ($) loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, unamortized loan fee	$ 8,600,000	$ 11,500,000
Accrued interest on loans	$ 5,500,000	$ 5,500,000
Financing Receivable, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]	Other assets	Other assets
PPP loans	$ 1,487,947,000	$ 1,402,147,000
Loans secured by real estate	69.00%
Loans unsecured	1.00%
Loans classified as troubled debt restructuring	$ 5,135,000	10,600,000
Loans secured for general commercial uses	30.00%
Allowance for credit losses	$ 13,838,000	$ 11,739,000	$ 16,625,000
Percentage of portfolio loans (as a percent)	0.0092	0.0083
Percentage of portfolio loans, net of government guarantees (as a percent)	0.0099	0.0097
Nonaccrual loans	$ 7,076,000	$ 11,650,000
Interest income which would have been earned on nonaccrual loans	434,000	744,000	856,000
Interest on nonaccrual loans reversed through interest income	10,000	10,000
Interest earned on nonaccrual loans	$ 2,200,000	1,600,000	$ 924,000
Number of commitments on TDR \| commitment	0
Charge offs on loans later classified as TDRs	$ 0	$ 0
Number of TDRs that defaulted within twelve months of restructure \| loan	0	0	0
Unfunded loan commitments	$ 110,000	$ 115,000
Loans	1,501,785,000	1,413,886,000
Asset Pledged as Collateral without Right
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	0	0
Net of government guarantees
Accounts, Notes, Loans and Financing Receivable [Line Items]
Nonaccrual loans	6,430,000	10,672,000
Commercial & industrial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	2,914,000	3,027,000	$ 4,348,000
Nonaccrual loans	3,294,000	4,350,000
Loans	358,128,000	448,338,000
Commercial & industrial loans \| PPP Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
PPP loans	$ 7,100,000	$ 118,200,000

Financing Receivable, Modifications, Number Of Commitments To Extend Financing

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Financing Receivable Recorded Investment Interest Income That Would Have Been Earned On Nonaccrual Loans

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Financing Receivables, Allowance For Credit Loss, Excluding Accrued Interest, Percentage of Portfolio Loans

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Financing Receivables, Allowance For Credit Loss, Excluding Accrued Interest, Percentage of Portfolio Loans, Net of Government Guarantees

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Financing Receivables Percentage Of Total Loans, Excluding PPP Loans, Secured By Real Estate

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Financing Receivables Percentage Of Total Loans, Excluding PPP Loans, Unsecured

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Financing receivables unfunded loan commitments to directors and officers.

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Amount, after allowance for credit loss, of accrued interest on financing receivable.

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Indicates line item in statement of financial position that includes accrued interest, after allowance for credit loss, on financing receivable.

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Amount of writeoff of accrued interest on financing receivable recognized by reversing interest income.

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

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Amortized cost excluding accrued interest, after allowance for credit loss, of financing receivable. Excludes net investment in lease.

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Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.

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Amortized cost excluding accrued interest, of financing receivable on nonaccrual status. Excludes net investment in lease.

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Number of financing receivable contracts modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

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Amount of interest income on financing receivable on nonaccrual status.

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Amount of unamortized loan commitment, origination, and other costs (fees) on financing receivable recognized as adjustment to yield. Excludes financing receivable covered under loss sharing agreement.

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Reflects the amount of the write-down related to a troubled debt restructuring.

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