INVESTMENT SECURITIES - Schedule of Gross Unrealized Losses and Fair Value of Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Estimated Fair Value
Less Than 12 Months	$ 2,761	$ 507,188
12 Months or More	546,745	878,229
Total	549,506	1,385,417
Unrealized Losses
Less Than 12 Months	(393)	(3,696)
12 Months or More	(15,534)	(35,342)
Total	(15,927)	(39,038)
U.S. Treasuries
Estimated Fair Value
Less Than 12 Months	0	272,564
12 Months or More	56,396	353,787
Total	56,396	626,351
Unrealized Losses
Less Than 12 Months	0	(1,376)
12 Months or More	(562)	(3,689)
Total	(562)	(5,065)
U.S. government-sponsored agencies
Estimated Fair Value
Less Than 12 Months		0
12 Months or More		994
Total		994
Unrealized Losses
Less Than 12 Months		0
12 Months or More		(16)
Total		(16)
State, county and municipal securities
Estimated Fair Value
Less Than 12 Months	0	3,953
12 Months or More	14,920	15,940
Total	14,920	19,893
Unrealized Losses
Less Than 12 Months	0	(17)
12 Months or More	(541)	(1,053)
Total	(541)	(1,070)
Corporate debt securities
Estimated Fair Value
Less Than 12 Months	1,050	383
12 Months or More	7,461	8,400
Total	8,511	8,783
Unrealized Losses
Less Than 12 Months	(376)	(13)
12 Months or More	(89)	(581)
Total	(465)	(594)
SBA pool securities
Estimated Fair Value
Less Than 12 Months	33	52,850
12 Months or More	12,745	17,491
Total	12,778	70,341
Unrealized Losses
Less Than 12 Months	0	(322)
12 Months or More	(691)	(1,232)
Total	(691)	(1,554)
Mortgage-backed securities
Estimated Fair Value
Less Than 12 Months	1,678	177,438
12 Months or More	455,223	481,617
Total	456,901	659,055
Unrealized Losses
Less Than 12 Months	(17)	(1,968)
12 Months or More	(13,651)	(28,771)
Total	$ (13,668)	$ (30,739)