Stockholders' Equity - Restricted Stock Unit Activity (Details) - Restricted Stock Units shares in Millions	6 Months Ended
	Jun. 30, 2022 $ / shares shares
Number of Units
Beginning balance (in shares) | shares	279.9
Units granted (in shares) | shares	166.0
Units vested (in shares) | shares	(54.2)
Units forfeited (in shares) | shares	(24.2)
Ending balance (in shares) | shares	367.5
Weighted-Average Grant-Date Fair Value
Beginning balance (in usd per share) | $ / shares	$ 134
Units granted (in usd per share) | $ / shares	159
Units vested (in usd per share) | $ / shares	108
Units forfeited (in usd per share) | $ / shares	140
Ending balance (in usd per share) | $ / shares	$ 149