v3.26.1
COMMITMENTS AND CONTINGENCIES - Additional Information (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Mar. 31, 2026
Jun. 30, 2025
Dec. 31, 2025
Mar. 31, 2025
Dec. 31, 2024
Commitments and Contingencies Disclosure [Line Items]          
Reserves for unfunded commitments $ 23,000   $ 20,200    
Loans and Leases Receivable, Commitments, Fixed Rates 92,000 $ 75,000      
Loans and Leases Receivable, Commitments, Variable Rates $ 4,600,000 $ 4,400,000      
Loan Commitments, Fixed Interest Rate Range, Minimum 0.00% 0.00%      
Loan Commitments, Fixed Interest Rate Range, Maximum 21.00% 21.00%      
Loan Commitments, Fixed Rate, Maturities, Minimum 1 year 1 year      
Loan Commitments, Fixed Rate, Maturities, Maximum 31 years 31 years 7 months 6 days      
Letters of credit issued to guarantee performance of a client to a third party $ 36,300   36,600    
Derivative, Notional Amount 26,054,666   22,586,161    
Stockholders' Equity Attributable to Parent 2,940,625   2,769,216 $ 2,501,235 $ 2,438,041
Estimated Litigation Liability 0   0    
Retained earnings          
Commitments and Contingencies Disclosure [Line Items]          
Stockholders' Equity Attributable to Parent 1,485,573   1,437,286 $ 1,304,636 $ 1,276,329
Credit Default Swap          
Commitments and Contingencies Disclosure [Line Items]          
Derivative, Notional Amount 360,800   335,000    
Commitments to Extend Credit          
Commitments and Contingencies Disclosure [Line Items]          
Commitments outstanding to extend credit $ 4,700,000   $ 4,500,000