LOANS - Loans by Class Modified as Troubled Debt Restructurings (Details) $ in Thousands	Sep. 30, 2017 USD ($) Contract	Dec. 31, 2016 USD ($) Contract	Sep. 30, 2016 USD ($) Contract
Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	19		27
Troubled debt restructuring loans	$ 783		$ 2,899
Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Troubled debt restructuring loans	$ 12,452	$ 14,209	$ 14,013
Purchased Loans By Class Modified
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	8		12
Troubled debt restructuring loans	$ 1,005		$ 1,914
Purchased Loans
Financing Receivable, Modifications [Line Items]
Troubled debt restructuring loans	$ 20,205	$ 23,543	$ 21,117
Commercial, financial and agricultural | Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	1		5
Troubled debt restructuring loans	$ 4		$ 59
Commercial, financial and agricultural | Purchased Loans By Class Modified
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	0		1
Troubled debt restructuring loans	$ 0		$ 76
Real estate – construction and development | Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	0		2
Troubled debt restructuring loans	$ 0		$ 251
Real estate – construction and development | Purchased Loans By Class Modified
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	0		0
Troubled debt restructuring loans	$ 0		$ 0
Real estate – commercial and farmland | Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	2		4
Troubled debt restructuring loans	$ 226		$ 1,658
Real estate – commercial and farmland | Purchased Loans By Class Modified
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	0		3
Troubled debt restructuring loans	$ 0		$ 708
Real estate – residential | Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	10		7
Troubled debt restructuring loans	$ 526		$ 887
Real estate – residential | Purchased Loans By Class Modified
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	8		8
Troubled debt restructuring loans	$ 1,005		$ 1,130
Consumer installment | Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	6		9
Troubled debt restructuring loans	$ 27		$ 44
Consumer installment | Purchased Loans By Class Modified
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	0		0
Troubled debt restructuring loans	$ 0		$ 0
Financing Receivables, 30 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	28		15
Troubled debt restructuring loans	$ 1,186		$ 793
Financing Receivables, 30 Days Past Due | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	14		15
Troubled debt restructuring loans	$ 2,286		$ 733
Financing Receivables, 30 Days Past Due | Commercial, financial and agricultural | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	4		5
Troubled debt restructuring loans	$ 58		$ 51
Financing Receivables, 30 Days Past Due | Commercial, financial and agricultural | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	1		2
Troubled debt restructuring loans	$ 5		$ 76
Financing Receivables, 30 Days Past Due | Real estate – construction and development | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	1		0
Troubled debt restructuring loans	$ 25		$ 0
Financing Receivables, 30 Days Past Due | Real estate – construction and development | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	0		1
Troubled debt restructuring loans	$ 0		$ 10
Financing Receivables, 30 Days Past Due | Real estate – commercial and farmland | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	4		5
Troubled debt restructuring loans	$ 200		$ 517
Financing Receivables, 30 Days Past Due | Real estate – commercial and farmland | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	5		1
Troubled debt restructuring loans	$ 1,945		$ 207
Financing Receivables, 30 Days Past Due | Real estate – residential | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	12		3
Troubled debt restructuring loans	$ 878		$ 219
Financing Receivables, 30 Days Past Due | Real estate – residential | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	7		11
Troubled debt restructuring loans	$ 333		$ 440
Financing Receivables, 30 Days Past Due | Consumer installment | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	7		2
Troubled debt restructuring loans	$ 25		$ 6
Financing Receivables, 30 Days Past Due | Consumer installment | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	1		0
Troubled debt restructuring loans	$ 3		$ 0
Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	109	117
Troubled debt restructuring loans	$ 12,452	$ 14,209
Accruing Loans | Commercial, financial and agricultural | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	4	4
Troubled debt restructuring loans	$ 44	$ 47
Accruing Loans | Commercial, financial and agricultural | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	0	1
Troubled debt restructuring loans	$ 0	$ 1
Accruing Loans | Real estate – construction and development | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	7	8
Troubled debt restructuring loans	$ 424	$ 686
Accruing Loans | Real estate – construction and development | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	3	6
Troubled debt restructuring loans	$ 1,022	$ 1,358
Accruing Loans | Real estate – commercial and farmland | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	16	16
Troubled debt restructuring loans	$ 4,769	$ 4,119
Accruing Loans | Real estate – commercial and farmland | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	15	20
Troubled debt restructuring loans	$ 6,308	$ 8,460
Accruing Loans | Real estate – residential | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	78	82
Troubled debt restructuring loans	$ 7,209	$ 9,340
Accruing Loans | Real estate – residential | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	119	123
Troubled debt restructuring loans	$ 12,875	$ 13,713
Accruing Loans | Consumer installment | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	4	7
Troubled debt restructuring loans	$ 6	$ 17
Accruing Loans | Consumer installment | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	0	3
Troubled debt restructuring loans	$ 0	$ 11
Accruing Loans | Financing Receivables, 30 Days Past Due | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	137	153
Troubled debt restructuring loans	$ 20,205	$ 23,543
Non-Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	72	69
Troubled debt restructuring loans	$ 1,715	$ 3,987
Non-Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	47	46
Troubled debt restructuring loans	$ 5,834	$ 4,600
Non-Accruing Loans | Commercial, financial and agricultural | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	13	15
Troubled debt restructuring loans	$ 129	$ 114
Non-Accruing Loans | Commercial, financial and agricultural | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	3	4
Troubled debt restructuring loans	$ 18	$ 91
Non-Accruing Loans | Real estate – construction and development | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	2	2
Troubled debt restructuring loans	$ 34	$ 34
Non-Accruing Loans | Real estate – construction and development | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	6	3
Troubled debt restructuring loans	$ 349	$ 30
Non-Accruing Loans | Real estate – commercial and farmland | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	5	5
Troubled debt restructuring loans	$ 210	$ 2,970
Non-Accruing Loans | Real estate – commercial and farmland | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	11	5
Troubled debt restructuring loans	$ 3,834	$ 2,402
Non-Accruing Loans | Real estate – residential | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	16	15
Troubled debt restructuring loans	$ 1,212	$ 739
Non-Accruing Loans | Real estate – residential | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	25	33
Troubled debt restructuring loans	$ 1,627	$ 2,077
Non-Accruing Loans | Consumer installment | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	36	32
Troubled debt restructuring loans	$ 130	$ 130
Non-Accruing Loans | Consumer installment | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | Contract	2	1
Troubled debt restructuring loans	$ 6	$ 0