Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net loss	$ (1,379)	$ (1,261)
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment	140	83
Unrealized holding gain (loss) on available-for-sale securities	0	(1)
Total other comprehensive income (loss)	140	82
Comprehensive loss	$ (1,239)	$ (1,179)