LOANS - Loans by Class Modified as Troubled Debt Restructurings (Details) - Loans Excluding Purchased Loan $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020 USD ($) contract	Mar. 31, 2019 USD ($) contract	Dec. 31, 2019 USD ($) contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	10	25
Troubled debt restructurings principal balances | $	$ 976	$ 2,934
Financing Receivables, 30 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	24	19
Troubled debt restructurings principal balances | $	$ 2,968	$ 1,668
Financing Receivables, 30 Days Past Due | Accruing Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	246		234
Troubled debt restructurings principal balances | $	$ 30,025		$ 29,609
Financing Receivables, 30 Days Past Due | Non-Accruing Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	94		95
Troubled debt restructurings principal balances | $	$ 6,221		$ 5,623
Commercial, financial and agricultural
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	0	1
Troubled debt restructurings principal balances | $	$ 0	$ 7
Commercial, financial and agricultural | Financing Receivables, 30 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	1	1
Troubled debt restructurings principal balances | $	$ 200	$ 3
Commercial, financial and agricultural | Financing Receivables, 30 Days Past Due | Accruing Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	5		5
Troubled debt restructurings principal balances | $	$ 575		$ 516
Commercial, financial and agricultural | Financing Receivables, 30 Days Past Due | Non-Accruing Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	15		17
Troubled debt restructurings principal balances | $	$ 334		$ 335
Consumer installment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	1	6
Troubled debt restructurings principal balances | $	$ 9	$ 45
Consumer installment | Financing Receivables, 30 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	0	2
Troubled debt restructurings principal balances | $	$ 0	$ 28
Consumer installment | Financing Receivables, 30 Days Past Due | Accruing Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	4		4
Troubled debt restructurings principal balances | $	$ 4		$ 8
Consumer installment | Financing Receivables, 30 Days Past Due | Non-Accruing Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	27		27
Troubled debt restructurings principal balances | $	$ 105		$ 107
Premium finance | Financing Receivables, 30 Days Past Due | Accruing Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	1		1
Troubled debt restructurings principal balances | $	$ 159		$ 156
Premium finance | Financing Receivables, 30 Days Past Due | Non-Accruing Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	0		0
Troubled debt restructurings principal balances | $	$ 0		$ 0
Real estate – construction and development
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	0	0
Troubled debt restructurings principal balances | $	$ 0	$ 0
Real estate – construction and development | Financing Receivables, 30 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	2	0
Troubled debt restructurings principal balances | $	$ 287	$ 0
Real estate – construction and development | Financing Receivables, 30 Days Past Due | Accruing Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	5		6
Troubled debt restructurings principal balances | $	$ 925		$ 936
Real estate – construction and development | Financing Receivables, 30 Days Past Due | Non-Accruing Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	4		3
Troubled debt restructurings principal balances | $	$ 289		$ 253
Real estate – commercial and farmland
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	1	1
Troubled debt restructurings principal balances | $	$ 64	$ 33
Real estate – commercial and farmland | Financing Receivables, 30 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	2	1
Troubled debt restructurings principal balances | $	$ 681	$ 163
Real estate – commercial and farmland | Financing Receivables, 30 Days Past Due | Accruing Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	19		21
Troubled debt restructurings principal balances | $	$ 5,587		$ 6,732
Real estate – commercial and farmland | Financing Receivables, 30 Days Past Due | Non-Accruing Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	9		8
Troubled debt restructurings principal balances | $	$ 2,415		$ 2,071
Real estate – residential
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	8	17
Troubled debt restructurings principal balances | $	$ 903	$ 2,849
Real estate – residential | Financing Receivables, 30 Days Past Due
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	19	15
Troubled debt restructurings principal balances | $	$ 1,800	$ 1,474
Real estate – residential | Financing Receivables, 30 Days Past Due | Accruing Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	212		197
Troubled debt restructurings principal balances | $	$ 22,775		$ 21,261
Real estate – residential | Financing Receivables, 30 Days Past Due | Non-Accruing Loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts | contract	39		40
Troubled debt restructurings principal balances | $	$ 3,078		$ 2,857