v3.26.1
INVESTMENT SECURITIES - Additional Information (Detail)
3 Months Ended 6 Months Ended
Jun. 30, 2026
USD ($)
security
Jun. 30, 2025
USD ($)
Jun. 30, 2026
USD ($)
security
Jun. 30, 2025
USD ($)
Dec. 31, 2025
USD ($)
security
Debt Securities, Available-for-sale [Line Items]          
Proceeds from sales of investment securities available for sale $ 29,700,000 $ 450,400,000 $ 70,950,000 $ 450,423,000  
Number of available-for-sale investment securities, unrealized loss position, less than twelve month category | security 50   50    
Number of available-for-sale investment securities, unrealized loss position, twelve month or more category | security 35   35    
Number of available-for-sale investment securities, unrealized loss position | security 85   85   57
Accrued interest reversal $ 600,000 $ 0 $ 600,000 $ 4,100,000  
Debt securities, available for sale 2,595,966,000   2,595,966,000   $ 1,906,535,000
Investment securities held to maturity 631,594,000   631,594,000   729,134,000
Debt securities, held-to-maturity, allowance for credit loss, excluding accrued interest 0   0   0
Asset Pledged as Collateral          
Debt Securities, Available-for-sale [Line Items]          
Debt securities, available for sale 2,000,000,000.0   2,000,000,000.0   1,400,000,000
Debt securities 397,300,000   397,300,000   406,500,000
Corporate notes          
Debt Securities, Available-for-sale [Line Items]          
Debt securities, available for sale 236,879,000   236,879,000   285,858,000
Asset-backed securities          
Debt Securities, Available-for-sale [Line Items]          
Debt securities, available for sale 301,492,000   301,492,000   237,813,000
Investment securities held to maturity 181,633,000   181,633,000   258,371,000
Debt securities, held-to-maturity, allowance for credit loss, excluding accrued interest $ 0   $ 0   $ 0