LOANS - Composition of loans receivable and loans held-for-sale (Details) - Total - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Residential 1-4 family	$ 323,425	$ 317,639
Residential 5+ multifamily	23,557	18,108
Construction of residential 1-4 family	11,451	11,197
Home equity lines of credit	33,162	33,771
Residential real estate	391,595	380,715
Commercial	261,600	249,311
Construction of commercial	10,737	9,988
Commercial real estate	272,337	259,299
Farm land	4,366	4,274
Vacant land	7,945	7,883
Real estate secured	676,243	652,171
Commercial and industrial	137,291	132,731
Municipal	17,994	17,494
Consumer	4,519	4,794
Loans receivable, gross	836,047	807,190
Deferred loan origination fees and costs, net	1,381	1,289
Allowance for loan losses	(7,058)	(6,776)
Loans receivable, net	830,370	801,703
Loans held-for-sale
Residential 1-4 family		$ 669