INVESTMENTS - Summary of Investment Securities by Estimated Maturity (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Held-to-Maturity Amortized Cost
Amortized Cost	$ 72,994	$ 76,960
Held-to-Maturity Market Value
Debt Securities, Held-to-maturity, Fair Value	66,244	68,989
Available-for-Sale Amortized Cost
Debt Securities, Available-for-sale, Amortized Cost	3,664,424	3,512,652
Available-for-Sale Market Value
Investment securities available-for-sale	3,386,562	3,183,776
One Year or Less [Member]
Held-to-Maturity Amortized Cost
Amortized Cost	0
Held-to-Maturity Market Value
Debt Securities, Held-to-maturity, Fair Value	0
Available-for-Sale Amortized Cost
Debt Securities, Available-for-sale, Amortized Cost	4,340
Available-for-Sale Market Value
Investment securities available-for-sale	3,261
After One Year Through Five Years [Member]
Held-to-Maturity Amortized Cost
Amortized Cost	5,766
Held-to-Maturity Market Value
Debt Securities, Held-to-maturity, Fair Value	5,804
Available-for-Sale Amortized Cost
Debt Securities, Available-for-sale, Amortized Cost	184,047
Available-for-Sale Market Value
Investment securities available-for-sale	166,002
After Five Years Through Ten Years [Member]
Held-to-Maturity Amortized Cost
Amortized Cost	29,806
Held-to-Maturity Market Value
Debt Securities, Held-to-maturity, Fair Value	27,746
Available-for-Sale Amortized Cost
Debt Securities, Available-for-sale, Amortized Cost	157,697
Available-for-Sale Market Value
Investment securities available-for-sale	133,531
After Ten Years [Member]
Held-to-Maturity Amortized Cost
Amortized Cost	1,480
Held-to-Maturity Market Value
Debt Securities, Held-to-maturity, Fair Value	1,247
Available-for-Sale Amortized Cost
Debt Securities, Available-for-sale, Amortized Cost	473,666
Available-for-Sale Market Value
Investment securities available-for-sale	386,101
Residential Mortgage Backed Securities [Member]
Held-to-Maturity Amortized Cost
Amortized Cost	0	0
Held-to-Maturity Market Value
Debt Securities, Held-to-maturity, Fair Value	0	0
Available-for-Sale Amortized Cost
Debt Securities, Available-for-sale, Amortized Cost	1,220,107	1,102,242
Available-for-Sale Market Value
Investment securities available-for-sale	1,140,315	998,542
Commercial Mortgage Backed Securities [Member]
Held-to-Maturity Amortized Cost
Amortized Cost	29,345	30,444
Held-to-Maturity Market Value
Debt Securities, Held-to-maturity, Fair Value	25,430	25,990
Available-for-Sale Amortized Cost
Debt Securities, Available-for-sale, Amortized Cost	339,721	382,727
Available-for-Sale Market Value
Investment securities available-for-sale	322,605	357,372
Collateralized Mortgage Backed Securities [Member]
Held-to-Maturity Amortized Cost
Amortized Cost	6,597	7,007
Held-to-Maturity Market Value
Debt Securities, Held-to-maturity, Fair Value	6,017	6,219
Available-for-Sale Amortized Cost
Debt Securities, Available-for-sale, Amortized Cost	715,460	620,315
Available-for-Sale Market Value
Investment securities available-for-sale	678,099	569,165
Asset-backed Securities [Member]
Held-to-Maturity Amortized Cost
Amortized Cost	0	0
Held-to-Maturity Market Value
Debt Securities, Held-to-maturity, Fair Value	0	0
Available-for-Sale Amortized Cost
Debt Securities, Available-for-sale, Amortized Cost	569,386	555,484
Available-for-Sale Market Value
Investment securities available-for-sale	$ 556,648	$ 534,103