LOANS AND THE ALLOWANCE FOR CREDIT LOSSES - Loan Loss Experience and Activity in Allowance for Credit Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Loan loss experience and activity in allowance for loan losses
Beginning balance	$ 12,040	$ 11,833	$ 12,042
Charge-offs	(508)	(249)	(231)
Recoveries	127	140	68
Provision (credit)	1,000	316	(46)
Ending balance	12,659	12,040	11,833
Commercial, financial and agricultural
Loan loss experience and activity in allowance for loan losses
Beginning balance	2,696	2,583	2,740
Charge-offs	(125)	(29)	(34)
Recoveries	5	34	10
Provision (credit)	370	108	(133)
Ending balance	2,946	2,696	2,583
Municipal
Loan loss experience and activity in allowance for loan losses
Beginning balance	590	623	758
Provision (credit)	3	(33)	(135)
Ending balance	593	590	623
Real estate loans - residential
Loan loss experience and activity in allowance for loan losses
Beginning balance	2,882	3,038	2,995
Charge-offs	(215)	(112)	(25)
Recoveries	35	52	24
Provision (credit)	(127)	(96)	44
Ending balance	2,575	2,882	3,038
Real estate loans - commercial
Loan loss experience and activity in allowance for loan losses
Beginning balance	5,386	5,209	5,040
Recoveries	4	2	1
Provision (credit)	532	175	168
Ending balance	5,922	5,386	5,209
Real estate loans - construction
Loan loss experience and activity in allowance for loan losses
Beginning balance	420	325	481
Provision (credit)	114	95	(156)
Ending balance	534	420	325
Installment
Loan loss experience and activity in allowance for loan losses
Beginning balance	66	13	18
Charge-offs	(168)	(108)	(2)
Recoveries	83	52	2
Provision (credit)	108	109	(5)
Ending balance	$ 89	66	13
All other loans
Loan loss experience and activity in allowance for loan losses
Beginning balance		42	10
Charge-offs			(170)
Recoveries			31
Provision (credit)		$ (42)	171
Ending balance			$ 42