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LOANS AND ALLOWANCE FOR LOAN LOSSES - Credit Quality Indicator (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	$ 1,543,528	$ 1,312,903
Not Rated
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	441,216	428,037
Pass
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	1,054,875	826,396
Special Mention
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	10,121	18,534
Substandard
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	29,872	29,701
Doubtful
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	7,444	10,235
Commercial and agricultural:
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	406,013	230,922
Commercial mortgages:
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	692,935	650,570
Commercial mortgages: | Construction
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	54,523	44,082
Commercial mortgages: | Construction | Not Rated
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	0	0
Commercial mortgages: | Construction | Pass
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	51,126	40,304
Commercial mortgages: | Construction | Special Mention
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	610	168
Commercial mortgages: | Construction | Substandard
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	2,787	3,610
Commercial mortgages: | Construction | Doubtful
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	0	0
Commercial mortgages: | Commercial mortgages
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	638,412	606,488
Commercial mortgages: | Commercial mortgages | Not Rated
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	0	0
Commercial mortgages: | Commercial mortgages | Pass
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	610,687	577,266
Commercial mortgages: | Commercial mortgages | Special Mention
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	6,732	12,451
Commercial mortgages: | Commercial mortgages | Substandard
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	18,755	12,356
Commercial mortgages: | Commercial mortgages | Doubtful
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	2,238	4,415
Residential mortgages
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	227,984	188,874
Residential and consumer finance receivable [Abstract]
Residential and consumer loans receivable	227,984	188,874
Residential mortgages | Performing
Residential and consumer finance receivable [Abstract]
Residential and consumer loans receivable	226,242	186,719
Residential mortgages | Non-Performing
Residential and consumer finance receivable [Abstract]
Residential and consumer loans receivable	1,742	2,155
Residential mortgages | Not Rated
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	226,242	186,719
Residential mortgages | Pass
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	0	0
Residential mortgages | Special Mention
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	0	0
Residential mortgages | Substandard
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	1,742	2,155
Residential mortgages | Doubtful
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	0	0
Consumer loans:
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	216,596	242,537
Consumer loans: | Home equity lines and loans
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	81,770	92,065
Residential and consumer finance receivable [Abstract]
Residential and consumer loans receivable	81,770	92,065
Consumer loans: | Home equity lines and loans | Performing
Residential and consumer finance receivable [Abstract]
Residential and consumer loans receivable	80,753	91,424
Consumer loans: | Home equity lines and loans | Non-Performing
Residential and consumer finance receivable [Abstract]
Residential and consumer loans receivable	1,017	641
Consumer loans: | Home equity lines and loans | Not Rated
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	80,753	91,424
Consumer loans: | Home equity lines and loans | Pass
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	0	0
Consumer loans: | Home equity lines and loans | Special Mention
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	0	0
Consumer loans: | Home equity lines and loans | Substandard
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	1,017	641
Consumer loans: | Home equity lines and loans | Doubtful
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	0	0
Consumer loans: | Indirect consumer loans
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	121,720	135,366
Residential and consumer finance receivable [Abstract]
Residential and consumer loans receivable	121,721	135,366
Consumer loans: | Indirect consumer loans | Performing
Residential and consumer finance receivable [Abstract]
Residential and consumer loans receivable	121,117	134,795
Consumer loans: | Indirect consumer loans | Non-Performing
Residential and consumer finance receivable [Abstract]
Residential and consumer loans receivable	604	571
Consumer loans: | Indirect consumer loans | Not Rated
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	121,116	134,795
Consumer loans: | Indirect consumer loans | Pass
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	0	0
Consumer loans: | Indirect consumer loans | Special Mention
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	0	0
Consumer loans: | Indirect consumer loans | Substandard
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	604	571
Consumer loans: | Indirect consumer loans | Doubtful
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	0	0
Consumer loans: | Direct consumer loans
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	13,106	15,106
Residential and consumer finance receivable [Abstract]
Residential and consumer loans receivable	13,105	15,106
Consumer loans: | Direct consumer loans | Performing
Residential and consumer finance receivable [Abstract]
Residential and consumer loans receivable	13,104	15,099
Consumer loans: | Direct consumer loans | Non-Performing
Residential and consumer finance receivable [Abstract]
Residential and consumer loans receivable	1	7
Consumer loans: | Direct consumer loans | Not Rated
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	13,105	15,099
Consumer loans: | Direct consumer loans | Pass
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	0	0
Consumer loans: | Direct consumer loans | Special Mention
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	0	0
Consumer loans: | Direct consumer loans | Substandard
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	1	7
Consumer loans: | Direct consumer loans | Doubtful
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	0	0
Commercial and industrial | Commercial and agricultural:
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	405,329	230,648
Commercial and industrial | Commercial and agricultural: | Not Rated
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	0	0
Commercial and industrial | Commercial and agricultural: | Pass
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	392,378	208,552
Commercial and industrial | Commercial and agricultural: | Special Mention
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	2,779	5,915
Commercial and industrial | Commercial and agricultural: | Substandard
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	4,966	10,361
Commercial and industrial | Commercial and agricultural: | Doubtful
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	5,206	5,820
Agricultural | Commercial and agricultural:
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	684	274
Agricultural | Commercial and agricultural: | Not Rated
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	0	0
Agricultural | Commercial and agricultural: | Pass
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	684	274
Agricultural | Commercial and agricultural: | Special Mention
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	0	0
Agricultural | Commercial and agricultural: | Substandard
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	0	0
Agricultural | Commercial and agricultural: | Doubtful
Finance receivable by credit quality indicator [Abstract]
Total ending loans balance	$ 0	$ 0

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