LOANS - Loans by Class Modified as Troubled Debt Restructurings (Details) $ in Thousands	Mar. 31, 2018 USD ($) contract	Dec. 31, 2017 USD ($) contract	Mar. 31, 2017 USD ($) contract
Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	8		5
Troubled debt restructuring loans | $	$ 1,155		$ 93
Purchased Loans By Class Modified
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	3		2
Troubled debt restructuring loans | $	$ 186		$ 355
Financing Receivables, 30 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	19		33
Troubled debt restructuring loans | $	$ 3,018		$ 1,632
Financing Receivables, 30 Days Past Due | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	9		13
Troubled debt restructuring loans | $	$ 906		$ 2,050
Financing Receivables, 30 Days Past Due | Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	100	105
Troubled debt restructuring loans | $	$ 11,375	$ 13,599
Financing Receivables, 30 Days Past Due | Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	138	134
Troubled debt restructuring loans | $	$ 20,650	$ 20,472
Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	72	70
Troubled debt restructuring loans | $	$ 3,290	$ 1,964
Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	41	46
Troubled debt restructuring loans | $	$ 3,858	$ 4,405
Commercial, financial and agricultural | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	2		0
Troubled debt restructuring loans | $	$ 125		$ 0
Commercial, financial and agricultural | Purchased Loans By Class Modified
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	1		0
Troubled debt restructuring loans | $	$ 7		$ 0
Commercial, financial and agricultural | Financing Receivables, 30 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	0		3
Troubled debt restructuring loans | $	$ 0		$ 55
Commercial, financial and agricultural | Financing Receivables, 30 Days Past Due | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	0		0
Troubled debt restructuring loans | $	$ 0		$ 0
Commercial, financial and agricultural | Financing Receivables, 30 Days Past Due | Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	4	4
Troubled debt restructuring loans | $	$ 39	$ 41
Commercial, financial and agricultural | Financing Receivables, 30 Days Past Due | Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	0	0
Troubled debt restructuring loans | $	$ 0	$ 0
Commercial, financial and agricultural | Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	13	12
Troubled debt restructuring loans | $	$ 224	$ 120
Commercial, financial and agricultural | Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	4	3
Troubled debt restructuring loans | $	$ 23	$ 16
Real estate – construction and development | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	1		0
Troubled debt restructuring loans | $	$ 4		$ 0
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 – construction and development | Financing Receivables, 30 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	0		1
Troubled debt restructuring loans | $	$ 0		$ 26
Real estate – construction and development | Financing Receivables, 30 Days Past Due | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	0		2
Troubled debt restructuring loans | $	$ 0		$ 336
Real estate – construction and development | Financing Receivables, 30 Days Past Due | Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	5	6
Troubled debt restructuring loans | $	$ 176	$ 417
Real estate – construction and development | Financing Receivables, 30 Days Past Due | Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	4	3
Troubled debt restructuring loans | $	$ 1,034	$ 1,018
Real estate – construction and development | Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	2	2
Troubled debt restructuring loans | $	$ 8	$ 34
Real estate – construction and development | Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	6	6
Troubled debt restructuring loans | $	$ 316	$ 340
Real estate – commercial and farmland | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	1		0
Troubled debt restructuring loans | $	$ 303		$ 0
Real estate – commercial and farmland | Purchased Loans By Class Modified
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	0		1
Troubled debt restructuring loans | $	$ 0		$ 231
Real estate – commercial and farmland | Financing Receivables, 30 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	2		3
Troubled debt restructuring loans | $	$ 1,971		$ 150
Real estate – commercial and farmland | Financing Receivables, 30 Days Past Due | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	1		3
Troubled debt restructuring loans | $	$ 351		$ 1,149
Real estate – commercial and farmland | Financing Receivables, 30 Days Past Due | Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	16	17
Troubled debt restructuring loans | $	$ 4,606	$ 6,937
Real estate – commercial and farmland | Financing Receivables, 30 Days Past Due | Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	14	14
Troubled debt restructuring loans | $	$ 6,745	$ 6,713
Real estate – commercial and farmland | Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	6	5
Troubled debt restructuring loans | $	$ 2,127	$ 204
Real estate – commercial and farmland | Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	8	10
Troubled debt restructuring loans | $	$ 2,234	$ 2,582
Real estate – residential | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	2		1
Troubled debt restructuring loans | $	$ 710		$ 77
Real estate – residential | Purchased Loans By Class Modified
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	2		1
Troubled debt restructuring loans | $	$ 179		$ 124
Real estate – residential | Financing Receivables, 30 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	17		18
Troubled debt restructuring loans | $	$ 1,047		$ 1,380
Real estate – residential | Financing Receivables, 30 Days Past Due | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	8		8
Troubled debt restructuring loans | $	$ 555		$ 565
Real estate – residential | Financing Receivables, 30 Days Past Due | Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	72	74
Troubled debt restructuring loans | $	$ 6,547	$ 6,199
Real estate – residential | Financing Receivables, 30 Days Past Due | Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	120	117
Troubled debt restructuring loans | $	$ 12,871	$ 12,741
Real estate – residential | Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	19	18
Troubled debt restructuring loans | $	$ 838	$ 1,508
Real estate – residential | Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	21	25
Troubled debt restructuring loans | $	$ 1,281	$ 1,462
Consumer installment | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	2		4
Troubled debt restructuring loans | $	$ 13		$ 16
Consumer installment | Purchased Loans By Class Modified
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	0		0
Troubled debt restructuring loans | $	$ 0		$ 0
Consumer installment | Financing Receivables, 30 Days Past Due | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	0		8
Troubled debt restructuring loans | $	$ 0		$ 21
Consumer installment | Financing Receivables, 30 Days Past Due | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	0		0
Troubled debt restructuring loans | $	$ 0		$ 0
Consumer installment | Financing Receivables, 30 Days Past Due | Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	3	4
Troubled debt restructuring loans | $	$ 7	$ 5
Consumer installment | Financing Receivables, 30 Days Past Due | Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	0	0
Troubled debt restructuring loans | $	$ 0	$ 0
Consumer installment | Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Loans Excluding Purchased Loan
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	32	33
Troubled debt restructuring loans | $	$ 93	$ 98
Consumer installment | Financing Receivables, 30 Days Past Due | Non-Accruing Loans | Purchased Loans
Financing Receivable, Modifications [Line Items]
Number of contracts | contract	2	2
Troubled debt restructuring loans | $	$ 4	$ 5