Loans and Allowance for Credit Losses on Loans - Loans Outstanding and Aging Analysis (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) loan	Dec. 31, 2022 USD ($) loan	Dec. 31, 2021 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	$ 2,073,720,000	$ 2,092,546,000
Non-accrual loans	7,992,000	2,432,000
Non-accrual loans with no allowance	$ 3,091,000	$ 2,432,000
Number of loans past due more than 90 days still accruing \| loan	0	0
Nonaccrual loans earning interest on cash basis	$ 0	$ 0
Nonaccrual interest income	0	0	$ 0
Accrued interest writeoff	206,000	48,000	$ 0
Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	2,073,720,000	2,092,546,000
Total past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	7,664,000	1,342,000
30-59 days past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	3,930,000	420,000
60-89 days past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	2,274,000	244,000
90 days or more past due 1 \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	1,460,000	678,000
Current \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	2,066,056,000	2,091,204,000
Commercial \| Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	153,750,000	173,547,000
Non-accrual loans	4,008,000	0
Non-accrual loans with no allowance	1,311,000	0
Commercial \| Commercial and industrial \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	153,750,000	173,547,000
Commercial \| Commercial and industrial \| Total past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	4,371,000	267,000
Commercial \| Commercial and industrial \| 30-59 days past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	2,991,000	3,000
Commercial \| Commercial and industrial \| 60-89 days past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	69,000	0
Commercial \| Commercial and industrial \| 90 days or more past due 1 \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	1,311,000	264,000
Commercial \| Commercial and industrial \| Current \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	149,379,000	173,280,000
Commercial real estate \| Commercial owner-occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	333,181,000	354,877,000
Non-accrual loans	434,000	1,563,000
Non-accrual loans with no allowance	434,000	1,563,000
Commercial real estate \| Commercial owner-occupied \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	333,181,000	354,877,000
Commercial real estate \| Commercial owner-occupied \| Total past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	767,000	0
Commercial real estate \| Commercial owner-occupied \| 30-59 days past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	618,000	0
Commercial real estate \| Commercial owner-occupied \| 60-89 days past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	0	0
Commercial real estate \| Commercial owner-occupied \| 90 days or more past due 1 \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	149,000	0
Commercial real estate \| Commercial owner-occupied \| Current \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	332,414,000	354,877,000
Commercial real estate \| Commercial real estate, non-owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	1,219,385,000	1,191,889,000
Non-accrual loans	3,081,000	0
Non-accrual loans with no allowance	877,000	0
Commercial real estate \| Commercial real estate, non-owner occupied \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	1,219,385,000	1,191,889,000
Commercial real estate \| Commercial real estate, non-owner occupied \| Total past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	2,204,000	0
Commercial real estate \| Commercial real estate, non-owner occupied \| 30-59 days past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	0	0
Commercial real estate \| Commercial real estate, non-owner occupied \| 60-89 days past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	2,204,000	0
Commercial real estate \| Commercial real estate, non-owner occupied \| 90 days or more past due 1 \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	0	0
Commercial real estate \| Commercial real estate, non-owner occupied \| Current \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	1,217,181,000	1,191,889,000
Commercial real estate \| Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	99,164,000	114,373,000
Non-accrual loans	0	0
Non-accrual loans with no allowance	0	0
Commercial real estate \| Construction \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	99,164,000	114,373,000
Commercial real estate \| Construction \| Total past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	0	0
Commercial real estate \| Construction \| 30-59 days past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	0	0
Commercial real estate \| Construction \| 60-89 days past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	0	0
Commercial real estate \| Construction \| 90 days or more past due 1 \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	0	0
Commercial real estate \| Construction \| Current \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	99,164,000	114,373,000
Residential loans \| Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	82,087,000	88,748,000
Non-accrual loans	469,000	778,000
Non-accrual loans with no allowance	469,000	778,000
Residential loans \| Home equity \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	82,087,000	88,748,000
Residential loans \| Home equity \| Total past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	43,000	977,000
Residential loans \| Home equity \| 30-59 days past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	43,000	319,000
Residential loans \| Home equity \| 60-89 days past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	0	244,000
Residential loans \| Home equity \| 90 days or more past due 1 \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	0	414,000
Residential loans \| Home equity \| Current \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	82,044,000	87,771,000
Residential loans \| Other residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	118,508,000	112,123,000
Non-accrual loans	0	0
Non-accrual loans with no allowance	0	0
Residential loans \| Other residential \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	118,508,000	112,123,000
Residential loans \| Other residential \| Total past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	83,000	93,000
Residential loans \| Other residential \| 30-59 days past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	83,000	93,000
Residential loans \| Other residential \| 60-89 days past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	0	0
Residential loans \| Other residential \| 90 days or more past due 1 \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	0	0
Residential loans \| Other residential \| Current \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	118,425,000	112,030,000
Consumer loans \| Installment and other consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	67,645,000	56,989,000
Non-accrual loans	0	91,000
Non-accrual loans with no allowance	0	91,000
Consumer loans \| Installment and other consumer loans \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	67,645,000	56,989,000
Consumer loans \| Installment and other consumer loans \| Total past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	196,000	5,000
Consumer loans \| Installment and other consumer loans \| 30-59 days past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	195,000	5,000
Consumer loans \| Installment and other consumer loans \| 60-89 days past due \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	1,000	0
Consumer loans \| Installment and other consumer loans \| 90 days or more past due 1 \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	0	0
Consumer loans \| Installment and other consumer loans \| Current \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, at amortized cost	$ 67,449,000	$ 56,984,000