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LOANS AND ALLOWANCE FOR LOAN LOSSES - Allowances (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Jun. 30, 2020	Dec. 31, 2019
Allowance for loan losses, by portfolio segment [Roll Forward]
Beginning balance	$ 26,233	$ 19,745	$ 23,478	$ 18,944	$ 18,944
Charge-offs	(2,489)	(405)	(2,921)	(853)
Recoveries	126	166	263	322
Net recoveries (charge-offs)	(2,363)	(239)	(2,658)	(531)
Provision	260	150	3,310	1,243
Ending balance	24,130	19,656	24,130	19,656	23,478
Ending allowance balance attributable to loans [Abstract]
Individually evaluated for impairment						$ 5,706	$ 8,097
Collectively evaluated for impairment						18,424	15,381
Total ending allowance balance	24,130	19,656	23,478	19,656	23,478	24,130	23,478
Loans [Abstract]
Loans individually evaluated for impairment						15,741	15,665
Loans collectively evaluated for  impairment						1,487,005	1,297,238
Total recorded investment in loans						1,502,746	1,312,903
Commercial and Agricultural
Allowance for loan losses, by portfolio segment [Roll Forward]
Beginning balance	11,191	5,429	10,227	5,383	5,383
Charge-offs	(36)	(48)	(65)	(55)
Recoveries	5	4	8	15
Net recoveries (charge-offs)	(31)	(44)	(57)	(40)
Provision	(2,833)	91	(1,843)	133
Ending balance	8,327	5,476	8,327	5,476	10,227
Ending allowance balance attributable to loans [Abstract]
Individually evaluated for impairment						5,431	6,000
Collectively evaluated for impairment						2,896	4,227
Total ending allowance balance	8,327	5,476	8,327	5,476	5,383	8,327	10,227
Loans [Abstract]
Loans individually evaluated for impairment						6,572	6,147
Loans collectively evaluated for  impairment						390,126	224,775
Total recorded investment in loans						396,698	230,922
Commercial Mortgages
Allowance for loan losses, by portfolio segment [Roll Forward]
Beginning balance	10,472	9,474	8,869	8,184	8,184
Charge-offs	(2,143)	0	(2,143)	0
Recoveries	0	1	0	2
Net recoveries (charge-offs)	(2,143)	1	(2,143)	2
Provision	2,220	70	3,823	1,359
Ending balance	10,549	9,545	10,549	9,545	8,869
Ending allowance balance attributable to loans [Abstract]
Individually evaluated for impairment						213	2,097
Collectively evaluated for impairment						10,336	6,772
Total ending allowance balance	10,549	9,545	8,869	8,184	8,184	10,549	8,869
Loans [Abstract]
Loans individually evaluated for impairment						7,162	8,844
Loans collectively evaluated for  impairment						665,378	641,726
Total recorded investment in loans						672,540	650,570
Residential mortgages
Allowance for loan losses, by portfolio segment [Roll Forward]
Beginning balance	1,421	1,215	1,252	1,226	1,226
Charge-offs	(13)	(39)	(13)	(41)
Recoveries	49	45	48	45
Net recoveries (charge-offs)	36	6	35	4
Provision	434	8	604	(1)
Ending balance	1,891	1,229	1,891	1,229	1,252
Ending allowance balance attributable to loans [Abstract]
Individually evaluated for impairment						0	0
Collectively evaluated for impairment						1,891	1,252
Total ending allowance balance	1,891	1,229	1,252	1,226	1,252	1,891	1,252
Loans [Abstract]
Loans individually evaluated for impairment						1,170	525
Loans collectively evaluated for  impairment						207,523	188,349
Total recorded investment in loans						208,693	188,874
Consumer Loans
Allowance for loan losses, by portfolio segment [Roll Forward]
Beginning balance	3,149	3,627	3,130	4,151	4,151
Charge-offs	(297)	(318)	(700)	(757)
Recoveries	72	116	207	260
Net recoveries (charge-offs)	(225)	(202)	(493)	(497)
Provision	439	(19)	726	(248)
Ending balance	3,363	3,406	3,363	3,406	3,130
Ending allowance balance attributable to loans [Abstract]
Individually evaluated for impairment						62	0
Collectively evaluated for impairment						3,301	3,130
Total ending allowance balance	$ 3,363	$ 3,406	$ 3,130	$ 4,151	$ 3,130	3,363	3,130
Loans [Abstract]
Loans individually evaluated for impairment						837	149
Loans collectively evaluated for  impairment						223,978	242,388
Total recorded investment in loans						$ 224,815	$ 242,537

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