Allowance for Credit Losses - Summary of Nonaccrual Loans Excluding Purchased Credit-Impaired (PCI) Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Financing Receivable Recorded Investment [Line Items]
Nonaccrual loans with a related ACL	$ 21,048	$ 21,478
Nonaccrual loans without a related ACL	8,352	9,356
Total, Non-Accrual Status	29,400	30,834
Commercial and Agriculture [Member]
Financing Receivable Recorded Investment [Line Items]
Nonaccrual loans with a related ACL	6,633	6,312
Nonaccrual loans without a related ACL	4,008	4,042
Total, Non-Accrual Status	10,641	10,354
Commercial Real Estate Owner Occupied [Member]
Financing Receivable Recorded Investment [Line Items]
Nonaccrual loans with a related ACL	185	53
Nonaccrual loans without a related ACL	1,440	2,778
Total, Non-Accrual Status	1,625	2,831
Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable Recorded Investment [Line Items]
Nonaccrual loans with a related ACL	7,981	8,469
Nonaccrual loans without a related ACL	594	624
Total, Non-Accrual Status	8,575	9,093
Residential Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Nonaccrual loans with a related ACL	6,102	6,202
Nonaccrual loans without a related ACL	1,945	1,535
Total, Non-Accrual Status	8,047	7,737
Farm Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Nonaccrual loans with a related ACL		98
Nonaccrual loans without a related ACL	365	377
Total, Non-Accrual Status	365	475
Lease Financing Receivable [Member]
Financing Receivable Recorded Investment [Line Items]
Nonaccrual loans with a related ACL	105	291
Total, Non-Accrual Status	105	291
Consumer and Other [Member]
Financing Receivable Recorded Investment [Line Items]
Nonaccrual loans with a related ACL	42	53
Total, Non-Accrual Status	$ 42	$ 53