Allowance for Loan Losses - Schedule of Amortized Cost Basis of Collateral Dependent Loans Individually Evaluated Expected Credit Losses and Related Allowance for Credit Losses (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Financing Receivable Recorded Investment [Line Items]
Loans individually evaluated for expected credit losses		$ 624
Loans individually evaluated allowance for credit losses		7
Real Estate Loan [Member]
Financing Receivable Recorded Investment [Line Items]
Loans individually evaluated for expected credit losses	$ 1,205
Other Loan [Member]
Financing Receivable Recorded Investment [Line Items]
Loans individually evaluated for expected credit losses	5,371
Amortized Cost Basis Of Collateral Dependent Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans individually evaluated allowance for credit losses	864
Commercial and Agriculture [Member] | Other Loan [Member]
Financing Receivable Recorded Investment [Line Items]
Loans individually evaluated for expected credit losses	4,846
Commercial and Agriculture [Member] | Amortized Cost Basis Of Collateral Dependent Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans individually evaluated allowance for credit losses	408
Commercial Real Estate Owner Occupied [Member]
Financing Receivable Recorded Investment [Line Items]
Loans individually evaluated for expected credit losses		232
Loans individually evaluated allowance for credit losses		6
Commercial Real Estate Non Owner Occupied [Member] | Real Estate Loan [Member]
Financing Receivable Recorded Investment [Line Items]
Loans individually evaluated for expected credit losses	1,205
Commercial Real Estate Non Owner Occupied [Member] | Amortized Cost Basis Of Collateral Dependent Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans individually evaluated allowance for credit losses	306
Residential Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Loans individually evaluated for expected credit losses		392
Loans individually evaluated allowance for credit losses		$ 1
Lease Financing Receivable [Member] | Other Loan [Member]
Financing Receivable Recorded Investment [Line Items]
Loans individually evaluated for expected credit losses	525
Lease Financing Receivable [Member] | Amortized Cost Basis Of Collateral Dependent Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Loans individually evaluated allowance for credit losses	$ 150