Summary of Option Activity (Details) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) $ / shares shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Beginning Balance, Options | shares	14.7
Granted, Options | shares	1.5
Exercised, Options | shares	(2.0)
Cancelled, Options | shares	(0.2)
Ending Balance, Options | shares	14.0
Exercisable as of December 31, 2019, Options | shares	8.7
Beginning Balance, Weighted-Average Exercise Price | $ / shares	$ 37.63
Granted, Weighted-Average Exercise Price | $ / shares	77.24
Exercised, Weighted-Average Exercise Price | $ / shares	26.35
Cancelled, Weighted-Average Exercise Price | $ / shares	55.28
Ending Balance, Weighted-Average Exercise Price | $ / shares	43.23
Exercisable as of December 31, 2019, Weighted-Average Exercise Price | $ / shares	$ 34.23
Outstanding as of December 31, 2019, Weighted-Average Remaining Contractual Term, years	5 years 4 months 24 days
Exercisable as of December 31, 2019, Weighted-Average Remaining Contractual Term, years	3 years 9 months 18 days
Outstanding as of December 31, 2019, Aggregate Intrinsic Value | $	$ 388.6
Exercisable as of December 31, 2019, Aggregate Intrinsic Value | $	$ 314.5