Allowance for Credit Losses - Summary of Nonaccrual Loans Excluding Purchased Credit-Impaired (PCI) Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Financing Receivable Recorded Investment [Line Items]
Nonaccrual loans with a related ACL	$ 23,167	$ 21,478
Nonaccrual loans without a related ACL	6,698	9,356
Total, Non-Accrual Status	29,865	30,834
Commercial and Agriculture [Member]
Financing Receivable Recorded Investment [Line Items]
Nonaccrual loans with a related ACL	6,363	6,312
Nonaccrual loans without a related ACL	3,943	4,042
Total, Non-Accrual Status	10,306	10,354
Commercial Real Estate Owner Occupied [Member]
Financing Receivable Recorded Investment [Line Items]
Nonaccrual loans with a related ACL	140	53
Nonaccrual loans without a related ACL	1,377	2,778
Total, Non-Accrual Status	1,517	2,831
Commercial Real Estate Non Owner Occupied [Member]
Financing Receivable Recorded Investment [Line Items]
Nonaccrual loans with a related ACL	9,713	8,469
Nonaccrual loans without a related ACL	564	624
Total, Non-Accrual Status	10,277	9,093
Residential Real Estate [Member]
Financing Receivable Recorded Investment [Line Items]
Nonaccrual loans with a related ACL	6,871	6,202
Nonaccrual loans without a related ACL	471	1,535
Total, Non-Accrual Status	7,342	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	343	377
Total, Non-Accrual Status	343	475
Lease Financing Receivable [Member]
Financing Receivable Recorded Investment [Line Items]
Nonaccrual loans with a related ACL	28	291
Total, Non-Accrual Status	28	291
Consumer and Other [Member]
Financing Receivable Recorded Investment [Line Items]
Nonaccrual loans with a related ACL	52	53
Total, Non-Accrual Status	$ 52	$ 53