Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Trade accounts receivable, allowances	$ 42	$ 236
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, number of shares authorized	30,000,000	30,000,000
Common stock, number of shares issued	11,868,896	11,710,549
Common stock, number of shares outstanding	11,868,896	11,710,549