LOANS AND ALLOWANCE FOR LOAN LOSSES - Loans by Class Modified as Troubled Debt Restructurings (Details) $ in Thousands	Dec. 31, 2017 USD ($) contract	Dec. 31, 2016 USD ($) contract
Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	32	58
Troubled debt restructurings not included above | $	$ 4,212	$ 4,522
Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	23	35
Troubled debt restructurings not included above | $	$ 3,635	$ 5,956
Financing Receivables, 1 to 29 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	27	22
Troubled debt restructurings not included above | $	$ 1,587	$ 3,524
Financing Receivables, 1 to 29 Days Past Due | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	13	21
Troubled debt restructurings not included above | $	$ 742	$ 995
Accruing Loans | Financing Receivables, 1 to 29 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	105	117
Troubled debt restructurings not included above | $	$ 13,599	$ 14,209
Accruing Loans | Financing Receivables, 1 to 29 Days Past Due | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	134	153
Troubled debt restructurings not included above | $	$ 20,472	$ 23,543
Non-Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	46	46
Troubled debt restructurings not included above | $	$ 4,405	$ 4,600
Non-Accruing Loans | Financing Receivables, 1 to 29 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	70	69
Troubled debt restructurings not included above | $	$ 1,964	$ 3,987
Commercial, financial and agricultural | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	2	6
Troubled debt restructurings not included above | $	$ 7	$ 58
Commercial, financial and agricultural | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	1	1
Troubled debt restructurings not included above | $	$ 5	$ 76
Commercial, financial and agricultural | Financing Receivables, 1 to 29 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	2	5
Troubled debt restructurings not included above | $	$ 47	$ 51
Commercial, financial and agricultural | Financing Receivables, 1 to 29 Days Past Due | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	1	2
Troubled debt restructurings not included above | $	$ 5	$ 76
Commercial, financial and agricultural | Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	0	1
Troubled debt restructurings not included above | $	$ 0	$ 1
Commercial, financial and agricultural | Accruing Loans | Financing Receivables, 1 to 29 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	4	4
Troubled debt restructurings not included above | $	$ 41	$ 47
Commercial, financial and agricultural | Non-Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	3	4
Troubled debt restructurings not included above | $	$ 16	$ 91
Commercial, financial and agricultural | Non-Accruing Loans | Financing Receivables, 1 to 29 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	12	15
Troubled debt restructurings not included above | $	$ 120	$ 114
Real estate – construction and development | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	0	2
Troubled debt restructurings not included above | $	$ 0	$ 250
Real estate – construction and development | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	0	0
Troubled debt restructurings not included above | $	$ 0	$ 0
Real estate – construction and development | Financing Receivables, 1 to 29 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	2	1
Troubled debt restructurings not included above | $	$ 261	$ 5
Real estate – construction and development | Financing Receivables, 1 to 29 Days Past Due | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	0	1
Troubled debt restructurings not included above | $	$ 0	$ 9
Real estate – construction and development | Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	3	6
Troubled debt restructurings not included above | $	$ 1,018	$ 1,358
Real estate – construction and development | Accruing Loans | Financing Receivables, 1 to 29 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	6	8
Troubled debt restructurings not included above | $	$ 417	$ 686
Real estate – construction and development | Non-Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	6	3
Troubled debt restructurings not included above | $	$ 340	$ 30
Real estate – construction and development | Non-Accruing Loans | Financing Receivables, 1 to 29 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	2	2
Troubled debt restructurings not included above | $	$ 34	$ 34
Real estate – commercial and farmland | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	7	4
Troubled debt restructurings not included above | $	$ 3,516	$ 1,656
Real estate – commercial and farmland | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	4	6
Troubled debt restructurings not included above | $	$ 1,311	$ 2,789
Real estate – commercial and farmland | Financing Receivables, 1 to 29 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	4	5
Troubled debt restructurings not included above | $	$ 419	$ 2,970
Real estate – commercial and farmland | Financing Receivables, 1 to 29 Days Past Due | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	2	0
Troubled debt restructurings not included above | $	$ 282	$ 0
Real estate – commercial and farmland | Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	14	20
Troubled debt restructurings not included above | $	$ 6,713	$ 8,460
Real estate – commercial and farmland | Accruing Loans | Financing Receivables, 1 to 29 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	17	16
Troubled debt restructurings not included above | $	$ 6,937	$ 4,119
Real estate – commercial and farmland | Non-Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	10	5
Troubled debt restructurings not included above | $	$ 2,582	$ 2,402
Real estate – commercial and farmland | Non-Accruing Loans | Financing Receivables, 1 to 29 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	5	5
Troubled debt restructurings not included above | $	$ 204	$ 2,970
Real estate – residential | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	12	34
Troubled debt restructurings not included above | $	$ 656	$ 2,495
Real estate – residential | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	18	28
Troubled debt restructurings not included above | $	$ 2,319	$ 3,091
Real estate – residential | Financing Receivables, 1 to 29 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	12	5
Troubled debt restructurings not included above | $	$ 838	$ 460
Real estate – residential | Financing Receivables, 1 to 29 Days Past Due | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	9	18
Troubled debt restructurings not included above | $	$ 452	$ 910
Real estate – residential | Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	117	123
Troubled debt restructurings not included above | $	$ 12,741	$ 13,713
Real estate – residential | Accruing Loans | Financing Receivables, 1 to 29 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	74	82
Troubled debt restructurings not included above | $	$ 6,199	$ 9,340
Real estate – residential | Non-Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	25	33
Troubled debt restructurings not included above | $	$ 1,462	$ 2,077
Real estate – residential | Non-Accruing Loans | Financing Receivables, 1 to 29 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	18	15
Troubled debt restructurings not included above | $	$ 1,508	$ 739
Consumer installment | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	11	12
Troubled debt restructurings not included above | $	$ 33	$ 63
Consumer installment | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	0	0
Troubled debt restructurings not included above | $	$ 0	$ 0
Consumer installment | Financing Receivables, 1 to 29 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	7	6
Troubled debt restructurings not included above | $	$ 22	$ 38
Consumer installment | Financing Receivables, 1 to 29 Days Past Due | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	1	0
Troubled debt restructurings not included above | $	$ 3	$ 0
Consumer installment | Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	0	3
Troubled debt restructurings not included above | $	$ 0	$ 11
Consumer installment | Accruing Loans | Financing Receivables, 1 to 29 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	4	7
Troubled debt restructurings not included above | $	$ 5	$ 17
Consumer installment | Non-Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	2	1
Troubled debt restructurings not included above | $	$ 5	$ 0
Consumer installment | Non-Accruing Loans | Financing Receivables, 1 to 29 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	33	32
Troubled debt restructurings not included above | $	$ 98	$ 130