LOANS - Analysis of Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	$ 29,193	$ 31,505	$ 31,779	$ 29,193	$ 31,779	$ 31,505
Recorded Investment With No Allowance	8,143	7,250	7,245	8,143	7,245	7,250
Recorded Investment With Allowance	18,786	20,551	20,532	18,786	20,532	20,551
Total Recorded Investment	26,929	27,801	27,777	26,929	27,777	27,801
Related Allowance	2,632	2,245	2,324	2,632	2,324	2,245
Average recorded investment	27,384	26,662	28,516	26,408	30,324	29,819
Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	69,427	48,750	53,652	69,427	53,652	48,750
Recorded Investment With No Allowance	12,836	8,198	10,362	12,836	10,362	8,198
Recorded Investment With Allowance	35,291	27,702	28,892	35,291	28,892	27,702
Total Recorded Investment	48,127	35,900	39,254	48,127	39,254	35,900
Related Allowance	2,013	3,241	3,239	2,013	3,239	3,241
Average recorded investment	43,732	37,578	38,817	39,988	42,049	40,817
Commercial, financial and agricultural | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	2,216	1,453	2,924	2,216	2,924	1,453
Recorded Investment With No Allowance	966	734	1,121	966	1,121	734
Recorded Investment With Allowance	838	613	1,331	838	1,331	613
Total Recorded Investment	1,804	1,347	2,452	1,804	2,452	1,347
Related Allowance	5	145	379	5	379	145
Average recorded investment	1,791	1,900	2,478	1,629	2,380	2,173
Commercial, financial and agricultural | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	5,499	4,170	5,333	5,499	5,333	4,170
Recorded Investment With No Allowance	631	70	345	631	345	70
Recorded Investment With Allowance	341	744	1,741	341	1,741	744
Total Recorded Investment	972	814	2,086	972	2,086	814
Related Allowance	0	400	800	0	800	400
Average recorded investment	670	1,450	1,128	737	831	827
Real estate – construction and development | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	1,444	1,467	1,655	1,444	1,655	1,467
Recorded Investment With No Allowance	720	471	532	720	532	471
Recorded Investment With Allowance	701	500	627	701	627	500
Total Recorded Investment	1,421	971	1,159	1,421	1,159	971
Related Allowance	46	48	81	46	81	48
Average recorded investment	1,110	1,065	1,179	971	1,160	1,122
Real estate – construction and development | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	16,066	9,060	9,268	16,066	9,268	9,060
Recorded Investment With No Allowance	312	282	1,189	312	1,189	282
Recorded Investment With Allowance	7,033	3,875	3,088	7,033	3,088	3,875
Total Recorded Investment	7,345	4,157	4,277	7,345	4,277	4,157
Related Allowance	255	1,114	537	255	537	1,114
Average recorded investment	6,561	4,218	3,885	5,356	3,807	3,877
Real estate – commercial and farmland | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	8,911	10,646	11,451	8,911	11,451	10,646
Recorded Investment With No Allowance	536	729	536	536	536	729
Recorded Investment With Allowance	7,021	8,873	9,938	7,021	9,938	8,873
Total Recorded Investment	7,557	9,602	10,474	7,557	10,474	9,602
Related Allowance	1,799	1,047	806	1,799	806	1,047
Average recorded investment	8,186	8,910	10,669	7,969	11,416	11,053
Real estate – commercial and farmland | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	20,297	14,596	16,492	20,297	16,492	14,596
Recorded Investment With No Allowance	3,013	1,224	1,516	3,013	1,516	1,224
Recorded Investment With Allowance	12,319	11,173	11,766	12,319	11,766	11,173
Total Recorded Investment	15,332	12,397	13,282	15,332	13,282	12,397
Related Allowance	872	906	1,140	872	1,140	906
Average recorded investment	13,282	12,840	13,658	12,513	16,063	15,329
Real estate – residential | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	15,964	17,416	15,211	15,964	15,211	17,416
Recorded Investment With No Allowance	5,298	4,828	4,558	5,298	4,558	4,828
Recorded Investment With Allowance	10,226	10,565	8,636	10,226	8,636	10,565
Total Recorded Investment	15,524	15,393	13,194	15,524	13,194	15,393
Related Allowance	782	1,005	1,058	782	1,058	1,005
Average recorded investment	15,726	14,294	13,683	15,308	14,814	14,930
Real estate – residential | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	27,028	20,867	22,462	27,028	22,462	20,867
Recorded Investment With No Allowance	8,393	6,574	7,224	8,393	7,224	6,574
Recorded Investment With Allowance	15,598	11,910	12,297	15,598	12,297	11,910
Total Recorded Investment	23,991	18,484	19,521	23,991	19,521	18,484
Related Allowance	886	821	762	886	762	821
Average recorded investment	22,932	19,002	20,088	21,217	21,308	20,743
Consumer installment | Loans Excluding Purchased Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	658	523	538	658	538	523
Recorded Investment With No Allowance	623	488	498	623	498	488
Recorded Investment With Allowance	0	0	0	0	0	0
Total Recorded Investment	623	488	498	623	498	488
Related Allowance	0	0	0	0	0	0
Average recorded investment	571	493	507	531	554	541
Consumer installment | Purchased Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Contractual Principal Balance	537	57	97	537	97	57
Recorded Investment With No Allowance	487	48	88	487	88	48
Recorded Investment With Allowance	0	0	0	0	0	0
Total Recorded Investment	487	48	88	487	88	48
Related Allowance	0	0	0	0	0	0
Average recorded investment	$ 287	$ 68	$ 58	$ 165	$ 40	$ 41