Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net (loss) income	$ (28,430)	$ 4,401	$ (23,066)	$ (59,773)
Other comprehensive (loss) income, net of tax:
Reclassification of realized gain on available-for-sale securities recognized in interest income	0	(108)	0	(21)
Change in unrealized gain (loss) on marketable securities available-for-sale	(18)	(75)	11	30
Foreign currency translation adjustments	(797)	1,256	(1,812)	1,356
Total other comprehensive (loss) income	(815)	1,073	(1,801)	1,365
Total comprehensive (loss) income	$ (29,245)	$ 5,474	$ (24,867)	$ (58,408)