LOANS AND THE ALLOWANCE FOR CREDIT LOSSES - Allowance for Loan Losses and Recorded Investment in Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014
Loan loss experience and activity in allowance for loan losses
Ending balance individually evaluated for impairment	$ 218		$ 137
Ending balance collectively evaluated for impairment	12,322		11,903
Total allowance for credit losses	12,540	$ 12,420	12,040	$ 12,210	$ 12,162	$ 11,833
Financing receivables, Ending balance individually evaluated for impairment	2,365		1,970
Financing receivables, Ending balance collectively evaluated for impairment	1,472,187		1,409,072
Total	1,477,285		1,414,280
Receivables acquired with deteriorated credit quality
Loan loss experience and activity in allowance for loan losses
Total	2,733		3,238
Commercial, financial and agricultural
Loan loss experience and activity in allowance for loan losses
Ending balance individually evaluated for impairment	40
Ending balance collectively evaluated for impairment	3,066		2,696
Total allowance for credit losses	3,106	3,198	2,696	2,833	2,925	2,583
Financing receivables, Ending balance individually evaluated for impairment	465		595
Financing receivables, Ending balance collectively evaluated for impairment	267,271		235,652
Total	268,530		237,451
Commercial, financial and agricultural | Receivables acquired with deteriorated credit quality
Loan loss experience and activity in allowance for loan losses
Total	794		1,204
Municipal
Loan loss experience and activity in allowance for loan losses
Ending balance collectively evaluated for impairment	603		590
Total allowance for credit losses	603	352	590	631	359	623
Financing receivables, Ending balance collectively evaluated for impairment	112,007		105,421
Total	112,007		105,421
Real estate loans - residential
Loan loss experience and activity in allowance for loan losses
Ending balance individually evaluated for impairment	178		137
Ending balance collectively evaluated for impairment	2,485		2,745
Total allowance for credit losses	2,663	2,809	2,882	2,959	3,043	3,038
Financing receivables, Ending balance individually evaluated for impairment	927		706
Financing receivables, Ending balance collectively evaluated for impairment	449,657		467,737
Total	450,584		468,443
Real estate loans - commercial
Loan loss experience and activity in allowance for loan losses
Ending balance collectively evaluated for impairment	5,507		5,386
Total allowance for credit losses	5,507	5,423	5,386	5,238	5,299	5,209
Financing receivables, Ending balance individually evaluated for impairment	973		647
Financing receivables, Ending balance collectively evaluated for impairment	581,480		555,323
Total	584,392		558,004
Real estate loans - commercial | Receivables acquired with deteriorated credit quality
Loan loss experience and activity in allowance for loan losses
Total	1,939		2,034
Real estate loans - construction
Loan loss experience and activity in allowance for loan losses
Ending balance collectively evaluated for impairment	574		420
Total allowance for credit losses	574	549	420	493	477	325
Financing receivables, Ending balance collectively evaluated for impairment	55,210		34,802
Total	55,210		34,802
Installment
Loan loss experience and activity in allowance for loan losses
Ending balance collectively evaluated for impairment	87		66
Total allowance for credit losses	87	$ 89	66	$ 56	$ 59	13
Financing receivables, Ending balance individually evaluated for impairment			22
Financing receivables, Ending balance collectively evaluated for impairment	6,547		10,093
Total	6,547		10,115
All other loans
Loan loss experience and activity in allowance for loan losses
Total allowance for credit losses						$ 42
Financing receivables, Ending balance collectively evaluated for impairment	15		44
Total	$ 15		$ 44