Share-Based Compensation - Summary of Stock Option Activity (Details) $ / shares in Units, shares in Thousands, $ in Millions	9 Months Ended
	Sep. 30, 2021 USD ($) $ / shares shares
Shares
Stock options outstanding - balance at beginning of period (in shares) | shares	14,689
Granted (in shares) | shares	140
Forfeited (in shares) | shares	(59)
Exercised (in shares) | shares	(3,510)
Stock options outstanding - balance at end of period (in shares) | shares	11,260
Stock options exercisable (in shares) | shares	9,692
Weighted-Average Exercise Price
Stock options outstanding - balance at beginning of period (in dollars per shares) | $ / shares	$ 50.82
Granted (in dollars per share) | $ / shares	110.41
Forfeited (in dollars per share) | $ / shares	107.83
Exercised (in dollars per share) | $ / shares	36.45
Stock options outstanding - balance at end of period (in dollars per shares) | $ / shares	55.75
Stock options exercisable (in dollars per share) | $ / shares	$ 47.71
Weighted-Average Remaining Contractual Term (Years)
Stock options outstanding (in years)	4 years 4 months 28 days
Stock options exercisable (in years)	3 years 9 months 10 days
Aggregate Intrinsic Value (In millions)
Stock options outstanding | $	$ 600
Stock options exercisable | $	$ 591