Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statement of Comprehensive Income [Abstract]
Net loss	$ (623,506)	$ (595,625)	$ (823,605)
Other comprehensive loss, before tax:
Unrealized gain (loss) on available-for-sale investments	(3,823)	(2,162)	771
Foreign currency adjustment	30	23	25
Comprehensive loss, before tax	(627,299)	(597,764)	(822,809)
Income tax benefit (expense) related to items of other comprehensive loss	0	170	(170)
Comprehensive loss, net of tax	$ (627,299)	$ (597,594)	$ (822,979)