Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net loss	$ (527,777)	$ (162,115)	$ (305,361)
Other comprehensive income (loss):
Unrealized gains (losses) on investments	7,078	(731)	1,434
Reclassification adjustment for net investment (gains) losses included in net loss	0	372	(57)
Net unrealized gains (losses) on investments	7,078	(359)	1,377
Currency translation adjustments	(8)	183	(132)
Total other comprehensive income (loss)	7,070	(176)	1,245
Comprehensive loss	$ (520,707)	$ (162,291)	$ (304,116)