LOAN CREDIT QUALITY AND RELATED ALLOWANCE FOR LOAN LOSSES - Allowance Activity (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2015	Dec. 31, 2014
Changes in allowance
Balance at the beginning of the period				$ 10,579,000				$ 10,144,000	$ 10,579,000	$ 10,144,000
Charge-offs									(1,361,000)	(2,534,000)
Recoveries									526,000	119,000
Provision for loan losses	$ 480,000	$ 520,000	$ 600,000	700,000	$ 1,605,000	$ 460,000	$ 300,000	485,000	2,300,000	2,850,000	$ 2,275,000
Balance at the end of the period	12,044,000				10,579,000				12,044,000	10,579,000	10,144,000
Allowance for Loan Losses:
Individually evaluated for impairment												$ 2,104,000	$ 2,093,000
Collectively evaluated for impairment												9,940,000	8,486,000
Total ending allowance balance	12,044,000			10,579,000	10,579,000			10,144,000	10,579,000	10,144,000	10,144,000	12,044,000	10,579,000
Loans
Individually evaluated for impairment												15,542,000	17,227,000
Collectively evaluated for impairment												1,030,736,000	899,193,000
Total												1,046,619,000	916,769,000
Commercial, Financial, and Agricultural
Changes in allowance
Balance at the beginning of the period				1,124,000				474,000	1,124,000	474,000
Charge-offs									(283,000)	(289,000)
Recoveries									176,000	18,000
Provision for loan losses									515,000	921,000
Balance at the end of the period	1,532,000				1,124,000				1,532,000	1,124,000	474,000
Allowance for Loan Losses:
Individually evaluated for impairment												75,000	298,000
Collectively evaluated for impairment												1,457,000	826,000
Total ending allowance balance	1,532,000			1,124,000	1,124,000			474,000	1,124,000	474,000	474,000	1,532,000	1,124,000
Loans
Individually evaluated for impairment												469,000	1,112,000
Collectively evaluated for impairment												163,603,000	123,044,000
Total												164,072,000	124,156,000
Residential Real Estate Mortgages
Changes in allowance
Balance at the beginning of the period				3,755,000				3,917,000	3,755,000	3,917,000
Charge-offs									(49,000)	(65,000)
Recoveries									81,000	15,000
Provision for loan losses									1,329,000	(112,000)
Balance at the end of the period	5,116,000				3,755,000				5,116,000	3,755,000	3,917,000
Allowance for Loan Losses:
Individually evaluated for impairment												376,000	147,000
Collectively evaluated for impairment												4,740,000	3,608,000
Total ending allowance balance	5,116,000			3,755,000	3,755,000			3,917,000	$ 3,755,000	$ 3,917,000	3,917,000	5,116,000	3,755,000
Loans
Individually evaluated for impairment												2,374,000	1,117,000
Collectively evaluated for impairment												523,468,000	456,294,000
Total												526,183,000	457,760,000
Residential Real Estate Mortgages | Financing receivable | Owners of rental properties
Changes in allowance
Concentration of loans (as a percent)									16.21%	16.01%
Commercial Real Estate Mortgage
Changes in allowance
Balance at the beginning of the period				4,205,000				4,079,000	$ 4,205,000	$ 4,079,000
Charge-offs									(743,000)	(2,038,000)
Recoveries									182,000	0
Provision for loan losses									573,000	2,164,000
Balance at the end of the period	4,217,000				4,205,000				4,217,000	4,205,000	4,079,000
Allowance for Loan Losses:
Individually evaluated for impairment												1,653,000	1,581,000
Collectively evaluated for impairment												2,564,000	2,624,000
Total ending allowance balance	4,217,000			4,205,000	4,205,000			4,079,000	$ 4,205,000	$ 4,079,000	4,079,000	4,217,000	4,205,000
Loans
Individually evaluated for impairment												12,487,000	13,973,000
Collectively evaluated for impairment												290,052,000	277,375,000
Total												302,539,000	291,348,000
Commercial Real Estate Mortgage | Financing receivable | Owners of rental properties
Changes in allowance
Concentration of loans (as a percent)									14.22%	14.67%
Construction Real Estate Mortgage
Changes in allowance
Balance at the beginning of the period				786,000				741,000	$ 786,000	$ 741,000
Charge-offs									(46,000)	0
Recoveries									23,000	22,000
Provision for loan losses									(603,000)	23,000
Balance at the end of the period	160,000				786,000				160,000	786,000	741,000
Allowance for Loan Losses:
Individually evaluated for impairment												0	67,000
Collectively evaluated for impairment												160,000	719,000
Total ending allowance balance	160,000			786,000	786,000			741,000	786,000	741,000	741,000	160,000	786,000
Loans
Individually evaluated for impairment												212,000	1,025,000
Collectively evaluated for impairment												26,612,000	20,971,000
Total												26,824,000	21,996,000
Installment Loans to Individuals
Changes in allowance
Balance at the beginning of the period				245,000				139,000	245,000	139,000
Charge-offs									(240,000)	(142,000)
Recoveries									64,000	64,000
Provision for loan losses									174,000	184,000
Balance at the end of the period	243,000				245,000				243,000	245,000	139,000
Allowance for Loan Losses:
Individually evaluated for impairment												0	0
Collectively evaluated for impairment												243,000	245,000
Total ending allowance balance	243,000			245,000	245,000			139,000	245,000	139,000	139,000	243,000	245,000
Loans
Individually evaluated for impairment												0	0
Collectively evaluated for impairment												27,001,000	21,509,000
Total												27,001,000	21,509,000
Unallocated
Changes in allowance
Balance at the beginning of the period				464,000				794,000	464,000	794,000
Charge-offs									0	0
Recoveries									0	0
Provision for loan losses									312,000	(330,000)
Balance at the end of the period	776,000				464,000				776,000	464,000	794,000
Allowance for Loan Losses:
Individually evaluated for impairment												0	0
Collectively evaluated for impairment												776,000	464,000
Total ending allowance balance	$ 776,000			$ 464,000	$ 464,000			$ 794,000	$ 464,000	$ 794,000	$ 794,000	776,000	464,000
Receivables Acquired with Deteriorated Credit Quality
Loans
Loans acquired with deteriorated credit quality												341,000	349,000
Receivables Acquired with Deteriorated Credit Quality | Commercial, Financial, and Agricultural
Loans
Loans acquired with deteriorated credit quality												0	0
Receivables Acquired with Deteriorated Credit Quality | Residential Real Estate Mortgages
Loans
Loans acquired with deteriorated credit quality												341,000	349,000
Receivables Acquired with Deteriorated Credit Quality | Commercial Real Estate Mortgage
Loans
Loans acquired with deteriorated credit quality												0	0
Receivables Acquired with Deteriorated Credit Quality | Construction Real Estate Mortgage
Loans
Loans acquired with deteriorated credit quality												0	0
Receivables Acquired with Deteriorated Credit Quality | Installment Loans to Individuals
Loans
Loans acquired with deteriorated credit quality												$ 0	$ 0