INVESTMENT SECURITIES - Schedule of Gross Unrealized Losses and Fair Value of Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Estimated Fair Value
Less Than 12 Months	$ 162,258	$ 1,405,288
12 Months or More	1,154,553	27,331
Total	1,316,811	1,432,619
Unrealized Losses
Less Than 12 Months	(827)	(56,816)
12 Months or More	(43,909)	(2,318)
Total	(44,736)	(59,134)
U.S. Treasuries
Estimated Fair Value
Less Than 12 Months	159,667	725,250
12 Months or More	537,313	0
Total	696,980	725,250
Unrealized Losses
Less Than 12 Months	(827)	(16,381)
12 Months or More	(10,966)	0
Total	(11,793)	(16,381)
U.S. government-sponsored agencies
Estimated Fair Value
Less Than 12 Months	0	979
12 Months or More	985	0
Total	985	979
Unrealized Losses
Less Than 12 Months	0	(57)
12 Months or More	(38)	0
Total	(38)	(57)
State, county and municipal securities
Estimated Fair Value
Less Than 12 Months	1,923	27,438
12 Months or More	19,754	0
Total	21,677	27,438
Unrealized Losses
Less Than 12 Months	0	(1,180)
12 Months or More	(944)	0
Total	(944)	(1,180)
Corporate debt securities
Estimated Fair Value
Less Than 12 Months	500	13,271
12 Months or More	8,527	1,155
Total	9,027	14,426
Unrealized Losses
Less Than 12 Months	0	(126)
12 Months or More	(850)	(270)
Total	(850)	(396)
SBA pool securities
Estimated Fair Value
Less Than 12 Months	42	17,806
12 Months or More	21,267	9,329
Total	21,309	27,135
Unrealized Losses
Less Than 12 Months	0	(1,298)
12 Months or More	(1,519)	(729)
Total	(1,519)	(2,027)
Mortgage-backed securities
Estimated Fair Value
Less Than 12 Months	126	620,544
12 Months or More	566,707	16,847
Total	566,833	637,391
Unrealized Losses
Less Than 12 Months	0	(37,774)
12 Months or More	(29,592)	(1,319)
Total	$ (29,592)	$ (39,093)