Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net loss	$ (9,111)	$ (11,267)	$ (16,887)
Other comprehensive (loss) income:
Foreign currency translation adjustments	(3)	3	(1)
Comprehensive loss	$ (9,114)	$ (11,264)	$ (16,888)