LOANS AND ALLOWANCE FOR LOAN LOSSES - Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Changes in the allowance for loan losses
Balance at beginning of period	$ 11,775	$ 10,939	$ 9,878
Charge-offs	(2,179)	(1,008)	(1,480)
Recoveries	34	55	101
Provision	16,484	1,789	2,440
Allowance contributed with mortgage combination transaction	(354)
Balance at end of period	25,760	11,775	10,939
Individually evaluated for impairment	1,296	574	1,043
Collectively evaluated for impairment	24,464	11,201	9,896
Purchased credit impaired loans
Changes in the allowance for loan losses
Balance at beginning of period	0
Charge-offs	(11)
Provision	95
Balance at end of period	84	0
Collectively evaluated for impairment	84
Commercial
Changes in the allowance for loan losses
Balance at beginning of period	10,098	8,605	7,804
Charge-offs	(1,932)	(998)	(1,024)
Recoveries	22	1	15
Provision	15,845	2,490	1,810
Allowance contributed with mortgage combination transaction	0
Balance at end of period	24,033	10,098	8,605
Individually evaluated for impairment	1,296	574	1,043
Collectively evaluated for impairment	22,737	9,524	7,562
Residential
Changes in the allowance for loan losses
Balance at beginning of period	1,272	1,405	1,119
Charge-offs	(224)	0	(166)
Recoveries	0	1	22
Provision	684	(134)	430
Allowance contributed with mortgage combination transaction	(354)
Balance at end of period	1,378	1,272	1,405
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	1,378	1,272	1,405
Residential | Purchased credit impaired loans
Changes in the allowance for loan losses
Balance at beginning of period	0
Charge-offs	(11)
Provision	95
Balance at end of period	84	0
Collectively evaluated for impairment	84
Home equity
Changes in the allowance for loan losses
Balance at beginning of period	327	684	705
Charge-offs	(23)	0	0
Recoveries	9	4	59
Provision	(15)	(361)	(80)
Allowance contributed with mortgage combination transaction	0
Balance at end of period	298	327	684
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	298	327	684
Consumer
Changes in the allowance for loan losses
Balance at beginning of period	78	245	250
Charge-offs	0	(10)	(290)
Recoveries	3	49	5
Provision	(30)	(206)	280
Allowance contributed with mortgage combination transaction	0
Balance at end of period	51	78	245
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	$ 51	$ 78	$ 245