Stock-based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Number of Stock Options
Beginning Balance (in shares)	34,413,889
Granted (in shares)	12,947,501
Exercised (in shares)	(2,750,380)
Canceled or forfeited (in shares)	(2,835,831)
Ending Balance (in shares)	41,775,179	34,413,889
Options Exercisable (in shares)	23,716,000
Weighted-Average Exercise Price per Share
Beginning Balance (in dollars per share)	$ 3.33
Granted (in dollars per share)	9.09
Exercised (in dollars per share)	3.43
Cancelled or forfeited (in dollars per share)	4.19
Ending Balance (in dollars per share)	5.05	$ 3.33
Options Exercisable (in dollars per share)	$ 3.39
Weighted-Average Remaining Contractual Life (years)
Options Outstanding	7 years 10 months 2 days	8 years 8 months 1 day
Options Exercisable	7 years 29 days
Aggregate Intrinsic Value
Options Outstanding	$ 142,076	$ 100,223
Options Exercisable	$ 110,520