Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net loss	$ (25,852)	$ (27,377)	$ (54,708)	$ (56,251)
Other comprehensive loss:
Foreign currency translation adjustment	(5)	(13)	(30)	(10)
Comprehensive loss	$ (25,857)	$ (27,390)	$ (54,738)	$ (56,261)