LOAN CREDIT QUALITY AND RELATED ALLOWANCE FOR LOAN LOSSES - Credit Quality Indicators (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	$ 1,391,846	$ 1,343,304
Pass
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	1,370,803	1,318,442
Special Mention
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	7,302	8,709
Substandard
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	13,741	16,153
Commercial, financial, and agricultural
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	163,285	164,743
Commercial, financial, and agricultural | Pass
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	160,899	162,694
Commercial, financial, and agricultural | Special Mention
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	234	180
Commercial, financial, and agricultural | Substandard
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	2,152	1,869
Consumer automobile
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	139,408	156,403
Consumer automobile | Pass
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	139,408	156,403
Consumer automobile | Special Mention
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	0	0
Consumer automobile | Substandard
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	0	0
Other consumer installment loans
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	9,277	19,940
Other consumer installment loans | Pass
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	9,257	19,938
Other consumer installment loans | Special Mention
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	0	0
Other consumer installment loans | Substandard
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	20	2
Residential | Real estate mortgage:
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	595,847	589,721
Residential | Real estate mortgage: | Pass
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	592,570	584,599
Residential | Real estate mortgage: | Special Mention
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	284	556
Residential | Real estate mortgage: | Substandard
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	2,993	4,566
Commercial | Real estate mortgage:
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	446,734	373,188
Commercial | Real estate mortgage: | Pass
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	432,158	355,616
Commercial | Real estate mortgage: | Special Mention
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	6,108	7,973
Commercial | Real estate mortgage: | Substandard
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	8,468	9,599
Construction | Real estate mortgage:
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	37,295	39,309
Construction | Real estate mortgage: | Pass
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	36,511	39,192
Construction | Real estate mortgage: | Special Mention
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	676	0
Construction | Real estate mortgage: | Substandard
Credit quality categories
Financing Receivable, before Allowance for Credit Loss, Fee and Loan in Process	$ 108	$ 117