Loans - Loan Balances (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Accounts Notes And Loans Receivable [Line Items]
Total loans	$ 16,050	$ 13,158
Allowance for credit losses	(38,849)	(37,160)	$ (34,196)	$ (28,511)
Loans Receivable [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	2,898,139	2,861,727
Allowance for credit losses	(38,849)	(37,160)
Net loans	2,859,290	2,824,567
Commercial and Agriculture [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	2,370	3,698
Allowance for credit losses	(7,737)	(7,587)	(3,316)	(3,011)
Commercial and Agriculture [Member] | Loans Receivable [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	302,663	304,793
Commercial Real Estate Owner Occupied [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	379	127
Allowance for credit losses	(4,652)	(4,723)	(5,733)	(4,565)
Commercial Real Estate Owner Occupied [Member] | Loans Receivable [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	367,419	377,321
Commercial Real Estate Non Owner Occupied [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	2,897	0
Allowance for credit losses	(12,968)	(12,056)	(11,760)	(14,138)
Commercial Real Estate Non Owner Occupied [Member] | Loans Receivable [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	1,185,688	1,161,894
Residential Real Estate [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	5,917	7,403
Allowance for credit losses	(9,074)	(8,489)	(5,934)	(3,145)
Residential Real Estate [Member] | Loans Receivable [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	676,802	659,841
Real Estate Construction [Member]
Accounts Notes And Loans Receivable [Line Items]
Allowance for credit losses	(3,433)	(3,388)	(3,920)	(2,293)
Real Estate Construction [Member] | Loans Receivable [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	267,737	260,409
Farm Real Estate [Member]
Accounts Notes And Loans Receivable [Line Items]
Allowance for credit losses	(320)	(260)	(269)	(291)
Farm Real Estate [Member] | Loans Receivable [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	24,908	24,771
Lease Financing Receivable [Member] | Loans Receivable [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	56,680	54,642
Consumer and Other [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	137	197
Allowance for credit losses	(306)	(341)	$ (354)	$ (98)
Consumer and Other [Member] | Loans Receivable [Member]
Accounts Notes And Loans Receivable [Line Items]
Total loans	$ 16,242	$ 18,056