INVESTMENT SECURITIES, Analysis of Gross Unrealized Losses (Details) $ in Thousands	Mar. 31, 2022 USD ($) Security	Dec. 31, 2021 USD ($)
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	$ 428,387	$ 389,464
12 months or more, fair value	137,702	41,453
Total fair value	566,089	430,917
Less than 12 months, unrealized losses	(21,565)	(7,514)
12 Months or more, unrealized losses	(10,914)	(1,163)
Total unrealized losses	$ (32,479)	(8,677)
Investment securities in an unrealized loss position less than 12 months | Security	347
Investment securities in an unrealized loss position more than 12 months | Security	67
Asset Pledged as Collateral [Member] | Public Deposits or Other Purposes [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Investment securities	$ 37,677	39,695
U.S. Treasury Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	78,054	63,254
12 months or more, fair value	9,957	2,066
Total fair value	88,011	65,320
Less than 12 months, unrealized losses	(2,725)	(673)
12 Months or more, unrealized losses	(464)	(38)
Total unrealized losses	(3,189)	(711)
Securities of U.S. Government Agencies and Corporations [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	39,241	48,288
12 months or more, fair value	50,456	30,158
Total fair value	89,697	78,446
Less than 12 months, unrealized losses	(1,180)	(942)
12 Months or more, unrealized losses	(4,273)	(884)
Total unrealized losses	(5,453)	(1,826)
Obligations of States and Political Subdivisions [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	28,790	11,680
12 months or more, fair value	2,848	934
Total fair value	31,638	12,614
Less than 12 months, unrealized losses	(2,339)	(233)
12 Months or more, unrealized losses	(461)	(68)
Total unrealized losses	(2,800)	(301)
Collateralized Mortgage Obligations [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	110,237	90,299
12 months or more, fair value	7,892	1,298
Total fair value	118,129	91,597
Less than 12 months, unrealized losses	(8,208)	(2,850)
12 Months or more, unrealized losses	(791)	(35)
Total unrealized losses	(8,999)	(2,885)
Mortgage-backed Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	172,065	175,943
12 months or more, fair value	66,549	6,997
Total fair value	238,614	182,940
Less than 12 months, unrealized losses	(7,113)	(2,816)
12 Months or more, unrealized losses	(4,925)	(138)
Total unrealized losses	$ (12,038)	$ (2,954)