LOANS AND ALLOWANCE FOR LOAN LOSSES - Receivables Past Due (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Financing Receivable, Past Due [Line Items]
Non-accrual	$ 9,325	$ 9,952
Loans Past Due 90 Days or More and Still Accruing	3	2
Aging of the recorded investment in loans past due [Abstract]
Past Due	4,900	10,480
Loans Not Past Due	1,581,084	1,531,018
Total ending loans balance	1,585,984	1,541,498
30 - 59 Days Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	3,284	4,598
60 - 89 Days Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	374	4,357
90 Days or More Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	1,242	1,525
Commercial and agricultural:
Aging of the recorded investment in loans past due [Abstract]
Total ending loans balance	400,719	370,252
Commercial and agricultural: \| Commercial and industrial
Financing Receivable, Past Due [Line Items]
Non-accrual	2,267	2,167
Loans Past Due 90 Days or More and Still Accruing	3	2
Aging of the recorded investment in loans past due [Abstract]
Past Due	1,081	564
Loans Not Past Due	399,200	369,404
Total ending loans balance	400,281	369,968
Commercial and agricultural: \| Commercial and industrial \| 30 - 59 Days Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	1,066	520
Commercial and agricultural: \| Commercial and industrial \| 60 - 89 Days Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	0	14
Commercial and agricultural: \| Commercial and industrial \| 90 Days or More Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	15	30
Commercial and agricultural: \| Agricultural
Aging of the recorded investment in loans past due [Abstract]
Past Due	0	0
Loans Not Past Due	438	284
Total ending loans balance	438	284
Commercial and agricultural: \| Agricultural \| 30 - 59 Days Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	0	0
Commercial and agricultural: \| Agricultural \| 60 - 89 Days Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	0	0
Commercial and agricultural: \| Agricultural \| 90 Days or More Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	0	0
Commercial mortgages:
Aging of the recorded investment in loans past due [Abstract]
Total ending loans balance	731,438	719,145
Commercial mortgages: \| Construction
Financing Receivable, Past Due [Line Items]
Non-accrual	51	55
Loans Past Due 90 Days or More and Still Accruing	0	0
Aging of the recorded investment in loans past due [Abstract]
Past Due	0	0
Loans Not Past Due	58,525	62,164
Total ending loans balance	58,525	62,164
Commercial mortgages: \| Construction \| 30 - 59 Days Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	0	0
Commercial mortgages: \| Construction \| 60 - 89 Days Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	0	0
Commercial mortgages: \| Construction \| 90 Days or More Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	0	0
Commercial mortgages: \| Commercial mortgages
Financing Receivable, Past Due [Line Items]
Non-accrual	4,541	4,415
Loans Past Due 90 Days or More and Still Accruing	0	0
Aging of the recorded investment in loans past due [Abstract]
Past Due	1,556	5,442
Loans Not Past Due	671,357	651,539
Total ending loans balance	672,913	656,981
Commercial mortgages: \| Commercial mortgages \| 30 - 59 Days Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	1,062	1,438
Commercial mortgages: \| Commercial mortgages \| 60 - 89 Days Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	174	3,696
Commercial mortgages: \| Commercial mortgages \| 90 Days or More Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	320	308
Residential mortgages
Financing Receivable, Past Due [Line Items]
Non-accrual	1,254	1,632
Loans Past Due 90 Days or More and Still Accruing	0	0
Aging of the recorded investment in loans past due [Abstract]
Past Due	899	1,684
Loans Not Past Due	244,944	238,329
Total ending loans balance	245,843	240,013
Residential mortgages \| 30 - 59 Days Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	449	817
Residential mortgages \| 60 - 89 Days Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	68	406
Residential mortgages \| 90 Days or More Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	382	461
Consumer loans:
Aging of the recorded investment in loans past due [Abstract]
Total ending loans balance	207,984	212,088
Consumer loans: \| Home equity lines and loans
Financing Receivable, Past Due [Line Items]
Non-accrual	673	1,159
Loans Past Due 90 Days or More and Still Accruing	0	0
Aging of the recorded investment in loans past due [Abstract]
Past Due	281	1,036
Loans Not Past Due	74,800	77,725
Total ending loans balance	75,081	78,761
Consumer loans: \| Home equity lines and loans \| 30 - 59 Days Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	3	521
Consumer loans: \| Home equity lines and loans \| 60 - 89 Days Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	0	41
Consumer loans: \| Home equity lines and loans \| 90 Days or More Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	278	474
Consumer loans: \| Indirect consumer loans
Financing Receivable, Past Due [Line Items]
Non-accrual	521	519
Loans Past Due 90 Days or More and Still Accruing	0	0
Aging of the recorded investment in loans past due [Abstract]
Past Due	1,072	1,718
Loans Not Past Due	120,125	119,135
Total ending loans balance	121,197	120,853
Consumer loans: \| Indirect consumer loans \| 30 - 59 Days Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	700	1,268
Consumer loans: \| Indirect consumer loans \| 60 - 89 Days Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	132	198
Consumer loans: \| Indirect consumer loans \| 90 Days or More Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	240	252
Consumer loans: \| Direct consumer loans
Financing Receivable, Past Due [Line Items]
Non-accrual	18	5
Loans Past Due 90 Days or More and Still Accruing	0	0
Aging of the recorded investment in loans past due [Abstract]
Past Due	11	36
Loans Not Past Due	11,695	12,438
Total ending loans balance	11,706	12,474
Consumer loans: \| Direct consumer loans \| 30 - 59 Days Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	4	34
Consumer loans: \| Direct consumer loans \| 60 - 89 Days Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	0	2
Consumer loans: \| Direct consumer loans \| 90 Days or More Past Due
Aging of the recorded investment in loans past due [Abstract]
Past Due	$ 7	$ 0

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Amount of financing receivable 90 days or more past due and still accruing.

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