Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net loss	$ (21,214)	$ (28,808)	$ (75,922)	$ (85,058)
Other comprehensive loss:
Foreign currency translation adjustment	13	(12)	(17)	(22)
Comprehensive loss	$ (21,201)	$ (28,820)	$ (75,939)	$ (85,080)