v3.26.3
COMMITMENTS AND CONTINGENCIES - Additional Information (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended 12 Months Ended
Mar. 31, 2026
Sep. 30, 2026
Dec. 31, 2025
Jun. 30, 2026
Sep. 30, 2025
Jun. 30, 2025
Dec. 31, 2024
Commitments and Contingencies Disclosure [Line Items]              
Reserves for unfunded commitments   $ 18,200 $ 20,200        
Financing Receivable, Commitment with Fixed Rate, Amount   106,100 75,000        
Financing Receivable, Commitment with Variable Rate, Amount   $ 4,700,000 $ 4,400,000        
Loan Commitments, Fixed Interest Rate Range, Minimum 0.00% 0.00%          
Loan Commitments, Fixed Interest Rate Range, Maximum 21.00% 36.00%          
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   $ 34,900 $ 36,600        
Derivative, Notional Amount   26,319,524 22,586,161        
Stockholders' Equity Attributable to Parent   2,881,482 2,769,216 $ 2,987,488 $ 2,631,855 $ 2,558,155 $ 2,438,041
Estimated Litigation Liability   0 0        
Retained earnings              
Commitments and Contingencies Disclosure [Line Items]              
Stockholders' Equity Attributable to Parent   1,589,622 1,437,286 $ 1,535,765 $ 1,399,577 $ 1,351,674 $ 1,276,329
Credit Default Swap              
Commitments and Contingencies Disclosure [Line Items]              
Derivative, Notional Amount   351,300 335,000        
Commitments to Extend Credit              
Commitments and Contingencies Disclosure [Line Items]              
Commitments outstanding to extend credit   $ 4,800,000 $ 4,500,000