LOANS - Modifications of Loans Performing (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment	$ 3,155,932	$ 2,600,358
Allowance for loan losses, Current Loans	137	128
Allowance for loan losses, Past Due 30-89	29
Allowance for loan losses, Non-Accrual	3,780	1,997
Allowance for loan losses, Total	3,946	2,125
TDRs [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	6,544	6,824
Past Due 30-89	69	985
Past due 90 days or more and still accruing		167
Non-Accrual	23,629	23,993
Recorded Investment	30,242	31,969
Commercial financial and agriculture | TDRs [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	30	583
Past Due 30-89	37	64
Non-Accrual	1,495	1,062
Recorded Investment	1,562	1,709
Commercial real estate | TDRs [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	4,641	4,299
Past Due 30-89	29	809
Past due 90 days or more and still accruing		109
Non-Accrual	19,439	19,991
Recorded Investment	24,109	25,208
Consumer real estate | TDRs [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	1,849	1,905
Past Due 30-89		112
Past due 90 days or more and still accruing		58
Non-Accrual	2,695	2,940
Recorded Investment	4,544	5,015
Consumer installment | TDRs [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	24	37
Past Due 30-89	3
Recorded Investment	$ 27	$ 37