ACCOUNTING STANDARDS (Details) - USD ($) $ in Thousands	Jun. 30, 2021		Mar. 31, 2021	Jan. 01, 2021	Dec. 31, 2020		Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Loans
Allowance for credit losses on loans	$ 32,457	[1]	$ 32,663		$ 35,820	[1]	$ 28,064	$ 20,804	$ 13,908
Liabilities:
Allowance for credit losses on OBSC exposures	718	[1]	$ 718		0
Total allowance for credit losses					35,820
Commercial financial and agriculture
Loans
Allowance for credit losses on loans	3,910				6,214
Commercial real estate
Loans
Allowance for credit losses on loans	17,573				24,319
Consumer real estate
Loans
Allowance for credit losses on loans	10,339				4,736
Consumer installment
Loans
Allowance for credit losses on loans	635				551
ASC 326
Loans
Allowance for credit losses on loans					$ 1,100
Liabilities:
Allowance for credit losses on OBSC exposures	$ 718
Transition Adjustment | ASC 326
Loans
Allowance for credit losses on loans				$ 397
Liabilities:
Allowance for credit losses on OBSC exposures				718
Total allowance for credit losses				1,115
Transition Adjustment | ASC 326 | Commercial financial and agriculture
Loans
Allowance for credit losses on loans				(1,153)
Transition Adjustment | ASC 326 | Commercial real estate
Loans
Allowance for credit losses on loans				(4,032)
Transition Adjustment | ASC 326 | Consumer real estate
Loans
Allowance for credit losses on loans				5,629
Transition Adjustment | ASC 326 | Consumer installment
Loans
Allowance for credit losses on loans				(47)
Reported under ASC 326 | ASC 326
Loans
Allowance for credit losses on loans				36,217
Liabilities:
Allowance for credit losses on OBSC exposures				718
Total allowance for credit losses				36,935
Reported under ASC 326 | ASC 326 | Commercial financial and agriculture
Loans
Allowance for credit losses on loans				5,061
Reported under ASC 326 | ASC 326 | Commercial real estate
Loans
Allowance for credit losses on loans				20,287
Reported under ASC 326 | ASC 326 | Consumer real estate
Loans
Allowance for credit losses on loans				10,365
Reported under ASC 326 | ASC 326 | Consumer installment
Loans
Allowance for credit losses on loans				$ 504

[1] – Beginning January 1, 2021, allowance for credit losses is based on current expected credit loss methodology. Prior to January 1, 2021, allowance for loan loss was based on incurred loss methodology