Stock-Based Compensation - Summary of Stock Option Activity for Company's Stock Option Plans (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Options outstanding, Shares, Beginning Balance	39,837,195
Stock Options granted, Shares	3,843,666
Stock option exercises, Shares	(3,346,352)
Stock Options Forfeited, Shares	(2,462,829)
Stock Options outstanding, Shares, Ending Balance	37,871,680	39,837,195
Stock Options exercised, Ending Balance	24,466,168
Stock Options outstanding, Weighted average per share exercise price, Beginning Balance	$ 3.49
Stock Options granted, Weighted average per share exercise price	19.94
Stock Options exercised, Weighted average per share exercise price	0.90
Stock Options forfeited, Weighted average per share exercise price	5.82
Stock Options outstanding, Weighted average per share exercise price, Ending Balance	5.24	$ 3.49
Stock Options exercised, Weighted average per share exercise price, Ending Balance	$ 3.44
Stock Options outstanding, Weighted average remaining contractual term (years)	8 years 7 days	8 years 10 months 13 days
Stock Options outstanding, Weighted average remaining contractual term (years)	7 years 6 months 10 days
Stock Options outstanding, Aggregate intrinsic value	$ 846	$ 101
Stock Options Exercisable, Intrinsic Value	$ 590