INVESTMENT SECURITIES, Analysis of Gross Unrealized Losses (Details) $ in Thousands	Sep. 30, 2023 USD ($) Security	Dec. 31, 2022 USD ($)
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	$ 81,212	$ 275,604
12 months or more, fair value	478,877	327,817
Total fair value	560,089	603,421
Less than 12 months, unrealized losses	(1,991)	(14,760)
12 Months or more, unrealized losses	(67,507)	(51,034)
Total unrealized losses	$ (69,498)	(65,794)
Investment securities in an unrealized loss position less than 12 months | Security	68
Investment securities in an unrealized loss position more than 12 months | Security	496
Allowance for credit losses on available-for-sale securities	$ 0	0
Asset Pledged as Collateral [Member] | Public Deposits or Other Purposes [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Investment securities	45,366	44,319
U.S. Treasury Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	10,775	54,574
12 months or more, fair value	83,726	56,872
Total fair value	94,501	111,446
Less than 12 months, unrealized losses	(53)	(1,680)
12 Months or more, unrealized losses	(4,534)	(4,162)
Total unrealized losses	(4,587)	(5,842)
Securities of U.S. Government Agencies and Corporations [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	17,526	45,261
12 months or more, fair value	97,438	69,635
Total fair value	114,964	114,896
Less than 12 months, unrealized losses	(183)	(1,341)
12 Months or more, unrealized losses	(8,675)	(8,465)
Total unrealized losses	(8,858)	(9,806)
Obligations of States and Political Subdivisions [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	9,900	40,479
12 months or more, fair value	34,011	10,049
Total fair value	43,911	50,528
Less than 12 months, unrealized losses	(430)	(3,022)
12 Months or more, unrealized losses	(6,473)	(2,620)
Total unrealized losses	(6,903)	(5,642)
Collateralized Mortgage Obligations [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	11,689	36,040
12 months or more, fair value	77,729	59,310
Total fair value	89,418	95,350
Less than 12 months, unrealized losses	(244)	(2,586)
12 Months or more, unrealized losses	(20,536)	(17,047)
Total unrealized losses	(20,780)	(19,633)
Mortgage-backed Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	31,322	99,250
12 months or more, fair value	185,973	131,951
Total fair value	217,295	231,201
Less than 12 months, unrealized losses	(1,081)	(6,131)
12 Months or more, unrealized losses	(27,289)	(18,740)
Total unrealized losses	$ (28,370)	$ (24,871)