LOANS HELD FOR INVESTMENT AND ALLOWANCE FOR CREDIT LOSSES (Activity in the allowance for credit losses) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	$ 22,026,000	$ 21,083,000	$ 23,816,000	$ 13,905,000
Provision for credit losses	(184,000)	1,615,000	(2,496,000)	6,605,000
Charge-Offs	(841,000)	(1,414,000)	(1,977,000)	(3,494,000)
Recoveries	1,174,000	1,173,000	2,832,000	2,172,000
Net Charge-Offs	333,000	(241,000)	855,000	(1,322,000)
Ending Balance	22,175,000	22,457,000	22,175,000	22,457,000
Impact of Adoption of ASC 326 [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				3,269,000
Commercial, Financial and Agricultural [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	1,957,000	2,247,000	2,204,000	1,675,000
Provision for credit losses	(56,000)	333,000	(370,000)	739,000
Charge-Offs	(32,000)	(186,000)	(101,000)	(548,000)
Recoveries	103,000	74,000	239,000	114,000
Net Charge-Offs	71,000	(112,000)	138,000	(434,000)
Ending Balance	1,972,000	2,468,000	1,972,000	2,468,000
Commercial, Financial and Agricultural [Member] | Impact of Adoption of ASC 326 [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				488,000
Real Estate - Construction [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	2,254,000	1,239,000	2,479,000	370,000
Provision for credit losses	505,000	716,000	280,000	1,283,000
Charge-Offs	0	0	0	0
Recoveries	0	0	0	0
Net Charge-Offs	0	0	0	0
Ending Balance	2,759,000	1,955,000	2,759,000	1,955,000
Real Estate - Construction [Member] | Impact of Adoption of ASC 326 [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				302,000
Real Estate - Commercial Mortgage [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	6,956,000	5,828,000	7,029,000	3,416,000
Provision for credit losses	587,000	742,000	(131,000)	1,516,000
Charge-Offs	0	0	0	(11,000)
Recoveries	26,000	70,000	671,000	261,000
Net Charge-Offs	26,000	70,000	671,000	250,000
Ending Balance	7,569,000	6,640,000	7,569,000	6,640,000
Real Estate - Commercial Mortgage [Member] | Impact of Adoption of ASC 326 [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				1,458,000
Real Estate - Residential [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	5,204,000	6,005,000	5,440,000	3,128,000
Provision for credit losses	(1,030,000)	(615,000)	(1,335,000)	1,089,000
Charge-Offs	(65,000)	(1,000)	(71,000)	(111,000)
Recoveries	244,000	51,000	319,000	91,000
Net Charge-Offs	179,000	50,000	248,000	(20,000)
Ending Balance	4,353,000	5,440,000	4,353,000	5,440,000
Real Estate - Residential [Member] | Impact of Adoption of ASC 326 [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				1,243,000
Real Estate - Home Equity [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	2,575,000	2,701,000	3,111,000	2,224,000
Provision for credit losses	(114,000)	40,000	(769,000)	141,000
Charge-Offs	(74,000)	(52,000)	(79,000)	(83,000)
Recoveries	70,000	64,000	194,000	97,000
Net Charge-Offs	(4,000)	12,000	115,000	14,000
Ending Balance	2,457,000	2,753,000	2,457,000	2,753,000
Real Estate - Home Equity [Member] | Impact of Adoption of ASC 326 [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				374,000
Consumer [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	3,080,000	3,063,000	3,553,000	3,092,000
Provision for credit losses	(76,000)	399,000	(171,000)	1,837,000
Charge-Offs	(670,000)	(1,175,000)	(1,726,000)	(2,741,000)
Recoveries	731,000	914,000	1,409,000	1,609,000
Net Charge-Offs	61,000	(261,000)	(317,000)	(1,132,000)
Ending Balance	$ 3,065,000	$ 3,201,000	$ 3,065,000	3,201,000
Consumer [Member] | Impact of Adoption of ASC 326 [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				$ (596,000)