Financial Instruments With Off-Balance Sheet Risk - Summary of Outstanding Contract Amounts of Off Balance Sheet Credit Risk Related Financial Instruments (Detail) - Unfunded Loan Commitment [Member] - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Schedule Of Loans And Leases Receivable Unfunded Commitments Under Line Of Credit [Line Items]
Unfunded commitments under lines of credit	$ 251,935	$ 231,149
Home equity loans [Member]
Schedule Of Loans And Leases Receivable Unfunded Commitments Under Line Of Credit [Line Items]
Unfunded commitments under lines of credit	46,960	43,798
Commercial real estate, construction, and land development [Member]
Schedule Of Loans And Leases Receivable Unfunded Commitments Under Line Of Credit [Line Items]
Unfunded commitments under lines of credit	60,239	62,146
Commercial and industrial [Member]
Schedule Of Loans And Leases Receivable Unfunded Commitments Under Line Of Credit [Line Items]
Unfunded commitments under lines of credit	$ 144,736	$ 125,205