INVESTMENT SECURITIES - Schedule of Maturities of Investment Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Investments, Debt and Equity Securities [Abstract]
Available-for-sale, amortized cost, one year or less	$ 10,322
Available-for-sale, amortized cost, after one through five years	114,551
Available-for-sale, amortized cost, after five through ten years	108,618
Available-for-sale, amortized cost, after ten years	1,023,469
Available-for-sale, amortized cost, securities not due on a single maturity date	2,385,646
Available-for-sale, amortized cost, other securities (no maturity)	203
Amortized Cost	3,642,809	$ 2,852,774
Available-for-sale, fair value, one year or less	10,230
Available-for-sale, fair value, after one through five years	114,184
Available-for-sale, fair value, after five through ten years	102,835
Available-for-sale, fair value, after ten years	836,811
Available-for-sale, fair value, securities not due on a single maturity date	2,201,958
Available-for-sale, fair value, other securities (no maturity)	203
Available-for-sale, fair value, total	$ 3,266,221	$ 2,529,426