CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Statement of Comprehensive Income [Abstract]
Net loss	$ (58,896)	$ (53,324)	$ (114,526)	$ (79,124)
Other comprehensive income (loss):
Change in net unrealized gains (losses) related to marketable securities	(56)	444	(168)	272
Foreign currency translation adjustments	(31)	(34)	115	(29)
Total other comprehensive (loss) income	(87)	410	(53)	243
Comprehensive loss	$ (58,983)	$ (52,914)	$ (114,579)	$ (78,881)