Net Loss Per Share - Reconciliation of Numerator and Denominators in Computing Net Loss per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Numerator
Net loss	$ (227,413)	$ (209,383)	$ (419,503)
Denominator
Weighted average common shares outstanding, basic (in shares)	55,880	53,706	43,078
Weighted average common shares outstanding, diluted (in shares)	55,880	53,706	43,078
Net loss per share, basic (in dollars per share)	$ (4.07)	$ (3.90)	$ (9.74)
Net loss per share, diluted (in dollars per share)	$ (4.07)	$ (3.90)	$ (9.74)