Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
ASSETS
Allowance for doubtful accounts, net	$ 50	$ 50
Stockholders equity:
Preferred stock, par value	$ 1.00	$ 1.00
Preferred stock, authorized shares	1,000,000	1,000,000
Preferred stock, issued shares	0	0
Preferred stock, outstanding shares	0	0
Common stock, par value	$ 0.60	$ 0.60
Common stock, authorized shares	20,000,000	20,000,000
Common stock, issued shares	13,844,584	13,754,749
Common stock, outstanding shares	13,844,584	13,754,749
Treasury stock, shares	192,094	30,422