Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Statement Of Financial Position [Abstract]
Trade accounts receivable, allowance for doubtful accounts	$ 675	$ 18
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	438,000	0
Preferred stock, shares outstanding	438,000	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	7,678,000	676,000
Common stock, shares outstanding	7,678,000	676,000