LOANS - Composition of loans receivable and loans held-for-sale (Details) - Total - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Residential 1-4 family	$ 335,383	$ 317,639
Residential 5+ multifamily	25,775	18,108
Construction of residential 1-4 family	12,035	11,197
Home equity lines of credit	33,930	33,771
Residential real estate	407,123	380,715
Commercial	272,395	249,311
Construction of commercial	11,544	9,988
Commercial real estate	283,939	259,299
Farm land	4,432	4,274
Vacant land	8,847	7,883
Real estate secured	704,341	652,171
Commercial and industrial	150,911	132,731
Municipal	18,608	17,494
Consumer	4,867	4,794
Loans receivable, gross	878,727	807,190
Deferred loan origination fees and costs, net	1,450	1,289
Allowance for loan losses	(7,381)	(6,776)
Loans receivable, net	872,796	801,703
Loans held-for-sale
Residential 1-4 family	$ 206	$ 669