CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
CONSOLIDATED BALANCE SHEETS
Trade receivables, allowance for doubtful accounts (in dollars)	$ 530	$ 341
Common stock, par value (in dollars per share)	$ 0	$ 0
Common stock, authorized shares	50,000	50,000
Common stock, shares issued	9,485	9,427
Common stock, shares outstanding	9,427	9,427
Preferred stock, par value (in dollars per share)	$ 1.00	$ 1.00
Preferred stock, authorized shares	5,000	5,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0