Condensed Consolidated Statements of Comprehensive Income (Loss) (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (1,956)	$ (1,908)
Other comprehensive income (loss):
Foreign currency translation (loss) gain	(3)	15
Net unrealized (loss) gain on marketable securities, net of tax	(336)	115
Comprehensive loss	$ (2,295)	$ (1,778)