CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Comprehensive Income (loss)
Net loss	$ (2,051)	$ (12,695)	$ (13,414)	$ (42,338)
Other comprehensive (loss) income:
Net unrealized (loss) gain on short-term investments	(1)	(1)		6
Total other comprehensive (loss) income	(1)	(1)		6
Comprehensive loss	$ (2,052)	$ (12,696)	$ (13,414)	$ (42,332)