v3.26.1
Investment Securities - Additional Information (Detail) - USD ($)
$ in Thousands
6 Months Ended
Jun. 30, 2026
Dec. 31, 2025
Debt Securities, Available-for-sale [Line Items]    
Allowance for credit loss $ 0 $ 0
Debt securities weighted average remaining contractual maturity term 25 years  
Total deposits $ 16,288,701 12,071,982
Investment in FHLB stock, impairment losses 0  
Investment Securities-AFS [Member]    
Debt Securities, Available-for-sale [Line Items]    
Pledged to secure amount 2,740,000 2,740,000
Total deposits 1,030,000 942,000
Secure public funds 708,500 548,600
Secured unused borrowing capacity 1,580,000 1,350,000
Other purposes 71,700 57,000
Pledged to secure unused borrowing capacity $ 2,360,000 $ 2,000,000