LOANS - Composition of loans receivable by risk rating grade (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Pass
Residential 1-4 family	$ 307,240	$ 291,928
Residential 5+ multifamily	16,129	11,556
Construction of residential 1-4 family	11,197	10,951
Home equity lines of credit	32,891	34,299
Residential real estate	367,457	348,734
Commercial	232,492	215,856
Construction of commercial	9,622	5,025
Commercial real estate	242,114	220,881
Farm land	4,024	2,912
Vacant land	7,806	6,513
Real estate secured	621,401	579,040
Commercial and industrial	129,219	137,914
Municipal	17,494	8,626
Consumer	4,744	5,353
Loans receivable, gross	772,858	730,933
Special mention
Residential 1-4 family	6,452	6,279
Residential 5+ multifamily	957	1,906
Construction of residential 1-4 family
Home equity lines of credit	710	512
Residential real estate	8,119	8,697
Commercial	4,456	7,818
Construction of commercial
Commercial real estate	4,456	7,818
Farm land
Vacant land	77	87
Real estate secured	12,652	16,602
Commercial and industrial	2,536	2,894
Municipal
Consumer	50	27
Loans receivable, gross	15,238	19,523
Substandard
Residential 1-4 family	3,947	2,832
Residential 5+ multifamily	1,022	163
Construction of residential 1-4 family
Home equity lines of credit	170	676
Residential real estate	5,139	3,671
Commercial	12,363	11,808
Construction of commercial	366	373
Commercial real estate	12,729	12,181
Farm land	250	1,002
Vacant land
Real estate secured	18,118	16,854
Commercial and industrial	976	665
Municipal
Consumer
Loans receivable, gross	19,094	17,519
Doubtful
Residential 1-4 family		89
Residential 5+ multifamily
Construction of residential 1-4 family
Home equity lines of credit
Residential real estate		89
Commercial
Construction of commercial
Commercial real estate
Farm land
Vacant land
Real estate secured		89
Commercial and industrial
Municipal
Consumer
Loans receivable, gross		89
Loss
Residential 1-4 family
Residential 5+ multifamily
Construction of residential 1-4 family
Home equity lines of credit
Residential real estate
Commercial
Construction of commercial
Commercial real estate
Farm land
Vacant land
Real estate secured
Commercial and industrial
Municipal
Consumer
Loans receivable, gross
Total
Residential 1-4 family	317,639	301,128
Residential 5+ multifamily	18,108	13,625
Construction of residential 1-4 family	11,197	10,951
Home equity lines of credit	33,771	35,487
Residential real estate	380,715	361,191
Commercial	249,311	235,482
Construction of commercial	9,988	5,398
Commercial real estate	259,299	240,880
Farm land	4,274	3,914
Vacant land	7,883	6,600
Real estate secured	652,171	612,585
Commercial and industrial	132,731	141,473
Municipal	17,494	8,626
Consumer	4,794	5,380
Loans receivable, gross	$ 807,190	$ 768,064