Loans (Impaired Loans) - Additional Information (Detail)		1 Months Ended	12 Months Ended
	Jul. 30, 2021	Apr. 30, 2022 Loan	Dec. 31, 2023 USD ($) Loan Contract	Dec. 31, 2022 USD ($) Contract Loan	Jan. 01, 2023 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired loans classified as modifications to borrowers experiencing financial difficulty				$ 3,600,000
Number of contracts modified | Loan			1	3
TDR impaired loans paid off | Loan		2		1
Increase to loan balance			$ 411,000
Term of loan	5 years
Allowance for loan losses			$ 25,024,000	$ 20,313,000
TDR loans, subsequently defaulted during the period			0	0
Maximum time for re-evaluation (in months)			12 months
Re-evaluation period for real estate			2 years
Unsecured consumer loans, credit card credits and overdraft lines of credit reach			90 days
Delinquent period for charging down consumer loans			90 days
Litigation and any deficiency charged off period			150 days
Delinquent period for charging down/allocated commercial and agricultural credits			120 days
ASU 2016-13 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses and unfunded commitment liability					$ 4,500,000
Allowance for redit losses and unfunded commitment liability, net of tax					$ 3,400,000
Consumer Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of contracts modified | Contract				1
Allowance for loan losses			$ 3,581,000	$ 998,000
Foreclosed residential real estate property			$ 0	0
Principal Forgiveness [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of contracts modified | Contract			0
Payment Changes from Monthly Payment to Principal and Interest at Maturity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses				$ 837,000