LOANS - Changes in allowance for loan losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Residential 1-4 family
Beginning balance	$ 2,393	$ 2,149
Acquisition Discount Transfer		10
Provision	306	(180)
Charge-offs
Recoveries	7	1
Ending balance	2,706	1,980
Residential 5+ multifamily
Beginning balance	446	413
Acquisition Discount Transfer
Provision	62	53
Charge-offs
Recoveries
Ending balance	508	466
Construction of residential 1-4 family
Beginning balance	75	83
Acquisition Discount Transfer
Provision	12	(6)
Charge-offs
Recoveries
Ending balance	87	77
Home equity lines of credit
Beginning balance	197	219
Acquisition Discount Transfer		1
Provision	81	(11)
Charge-offs
Recoveries
Ending balance	278	209
Residential real estate
Beginning balance	3,111	2,864
Acquisition Discount Transfer		11
Provision	461	(144)
Charge-offs
Recoveries	7	1
Ending balance	3,579	2,732
Commercial
Beginning balance	3,742	3,048
Acquisition Discount Transfer		488
Provision	758	276
Charge-offs		(9)
Recoveries	19
Ending balance	4,519	3,803
Construction of commercial
Beginning balance	104	122
Acquisition Discount Transfer
Provision	22	21
Charge-offs
Recoveries
Ending balance	126	143
Commercial real estate
Beginning balance	3,846	3,170
Acquisition Discount Transfer		488
Provision	780	297
Charge-offs		(9)
Recoveries	19
Ending balance	4,645	3,946
Farm land
Beginning balance	47	33
Acquisition Discount Transfer
Provision	5	14
Charge-offs
Recoveries
Ending balance	52	47
Vacant land
Beginning balance	71	100
Acquisition Discount Transfer
Provision	73	(11)
Charge-offs
Recoveries
Ending balance	144	89
Real estate secured
Beginning balance	7,075	6,167
Acquisition Discount Transfer		499
Provision	1,319	156
Charge-offs		(9)
Recoveries	26	1
Ending balance	8,420	6,814
Commercial real estate
Beginning balance	1,145	1,158
Acquisition Discount Transfer		164
Provision	(74)	(61)
Charge-offs		(30)
Recoveries		2
Ending balance	1,071	1,233
Municipal
Beginning balance	46	12
Acquisition Discount Transfer
Provision	7	2
Charge-offs
Recoveries
Ending balance	53	14
Consumer
Beginning balance	60	56
Acquisition Discount Transfer
Provision	51	(3)
Charge-offs	(12)	(6)
Recoveries	3	4
Ending balance	102	51
Unallocated
Beginning balance	569	438
Acquisition Discount Transfer
Provision	403	200
Charge-offs
Recoveries
Ending balance	972	638
Troubled debt restructurings
Beginning balance	8,895	7,831
Acquisition Discount Transfer		663
Provision	1,706	294
Charge-offs	(12)	(45)
Recoveries	29	7
Ending balance	$ 10,618	$ 8,750