INVESTMENT SECURITIES - Schedule of Held-to-Maturity Securities with Unrealized Losses (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Estimated Fair Value
Less than 12 months, estimated fair value	$ 12,794	$ 48,983
12 months or more, estimated fair value	102,895	65,555
Total estimated fair value	115,689	114,538
Unrealized Losses
Less than 12 months, unrealized losses	(1,046)	(3,413)
12 months or more, unrealized losses	(25,124)	(16,913)
Total unrealized losses	(26,170)	(20,326)
State, county and municipal securities
Estimated Fair Value
Less than 12 months, estimated fair value	0	16,512
12 months or more, estimated fair value	24,555	10,013
Total estimated fair value	24,555	26,525
Unrealized Losses
Less than 12 months, unrealized losses	0	(1,488)
12 months or more, unrealized losses	(7,350)	(3,892)
Total unrealized losses	(7,350)	(5,380)
Mortgage-backed securities
Estimated Fair Value
Less than 12 months, estimated fair value	12,794	32,471
12 months or more, estimated fair value	78,340	55,542
Total estimated fair value	91,134	88,013
Unrealized Losses
Less than 12 months, unrealized losses	(1,046)	(1,925)
12 months or more, unrealized losses	(17,774)	(13,021)
Total unrealized losses	$ (18,820)	$ (14,946)