Loans - Non-Accrual Loans, Segregated by Class of Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Financing Receivable, Nonaccrual	$ 72,350	$ 70,482
Financing Receivable, Nonaccrual, No Allowance	38,991	38,116
Commercial Portfolio Segment [Member]
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Financing Receivable, Nonaccrual	45,005	50,659
Financing Receivable, Nonaccrual, No Allowance	20,848	26,693
Commercial and Industrial Total Energy Loans [Member]
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Financing Receivable, Nonaccrual	2,523	3,023
Financing Receivable, Nonaccrual, No Allowance	1,303	1,304
Commercial Real Estate Owner Occupied
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Financing Receivable, Nonaccrual	13,764	7,581
Financing Receivable, Nonaccrual, No Allowance	10,965	4,782
Commercial Real Estate Non-Owner Occupied
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Financing Receivable, Nonaccrual	580	465
Financing Receivable, Nonaccrual, No Allowance	580	465
Construction Loans [Member]
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Financing Receivable, Nonaccrual	2,407	1,874
Financing Receivable, Nonaccrual, No Allowance	785	202
Total consumer real estate loans [Member]
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Financing Receivable, Nonaccrual	7,811	6,615
Financing Receivable, Nonaccrual, No Allowance	4,331	4,486
Consumer Loan [Member]
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Financing Receivable, Nonaccrual	260	265
Financing Receivable, Nonaccrual, No Allowance	$ 179	$ 184