Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net loss	$ (25,478)	$ (61,822)
Other comprehensive income (loss):
Unrealized gain on investments	2	27
Foreign currency translation adjustments	212	(327)
Other comprehensive income (loss)	214	(300)
Comprehensive loss	$ (25,264)	$ (62,122)