LOANS (Details) - USD ($)
$ in Thousands
Mar. 31, 2019
Dec. 31, 2018
Mar. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Loans and Leases Receivable Disclosure [Line Items]          
Gross loans, Amount $ 872,634 $ 848,431   $ 752,740  
Allowance for loan losses (11,857) (11,680) $ (10,236) (9,757) $ (8,590)
Deferred loan fees, net (1,508) (1,223)   (845)  
Net loans 859,269 835,528   742,138  
Commercial real estate          
Loans and Leases Receivable Disclosure [Line Items]          
Gross loans, Amount 373,435 364,867   371,510  
Allowance for loan losses (4,247) (4,152) (4,607) (4,483) (4,503)
Commercial          
Loans and Leases Receivable Disclosure [Line Items]          
Gross loans, Amount 382,550 361,782   240,223  
Allowance for loan losses (5,746) (5,742) (3,668) (3,280) (2,513)
Residential real estate          
Loans and Leases Receivable Disclosure [Line Items]          
Gross loans, Amount 54,898 57,361   67,724  
Allowance for loan losses (240) (251) (292) (300) (328)
Construction and land development          
Loans and Leases Receivable Disclosure [Line Items]          
Gross loans, Amount 42,441 44,606   55,828  
Allowance for loan losses (734) (738) (939) (965) (882)
Consumer          
Loans and Leases Receivable Disclosure [Line Items]          
Gross loans, Amount 19,310 19,815   17,455  
Allowance for loan losses $ (812) $ (710) $ (678) $ (649) $ (279)