LOANS AND ALLOWANCE FOR LOAN LOSSES - Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Changes in the allowance for loan losses
Balance at beginning of period	$ 10,939	$ 9,878	$ 9,101
Charge-offs	(1,008)	(1,480)	(1,497)
Recoveries	55	101	101
Provision	1,789	2,440	2,173
Balance at end of period	11,775	10,939	9,878
Individually evaluated for impairment	574	1,043	1,188
Collectively evaluated for impairment	11,201	9,896	8,690
Commercial
Changes in the allowance for loan losses
Balance at beginning of period	8,605	7,804	7,181
Charge-offs	(998)	(1,024)	(1,138)
Recoveries	1	15	39
Provision	2,490	1,810	1,722
Balance at end of period	10,098	8,605	7,804
Individually evaluated for impairment	574	1,043	1,172
Collectively evaluated for impairment	9,524	7,562	6,632
Residential
Changes in the allowance for loan losses
Balance at beginning of period	1,405	1,119	990
Charge-offs	0	(166)	(141)
Recoveries	1	22	40
Provision	(134)	430	230
Balance at end of period	1,272	1,405	1,119
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	1,272	1,405	1,119
Home Equity
Changes in the allowance for loan losses
Balance at beginning of period	684	705	728
Charge-offs	0	0	(109)
Recoveries	4	59	4
Provision	(361)	(80)	82
Balance at end of period	327	684	705
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	327	684	705
Consumer
Changes in the allowance for loan losses
Balance at beginning of period	245	250	202
Charge-offs	(10)	(290)	(109)
Recoveries	49	5	18
Provision	(206)	280	139
Balance at end of period	78	245	250
Individually evaluated for impairment	0	0	16
Collectively evaluated for impairment	$ 78	$ 245	$ 234