Stock Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding, beginning of period (in shares)		9.7	9.7	9.4
Options granted (in shares)		2.2	1.7	1.7
Options exercised (in shares)		(1.2)	(1.4)	(1.0)
Options canceled/forfeited (in shares)		(0.5)	(0.3)	(0.4)
Options outstanding, end of period (in shares)		10.2	9.7	9.7
Options vested and expected to vest (in shares)	[1]	10.0
Options vested (in shares)		4.8
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Options outstanding, beginning of period (in dollars per share)		$ 46.25	$ 38.09	$ 33.23
Options granted (in dollars per share)		79.61	76.67	58.07
Options exercised (in dollars per share)		33.84	28.99	24.77
Options canceled/forfeited (in dollars per share)		66.16	54.13	45.12
Options outstanding, end of period (in dollars per share)		53.64	$ 46.25	$ 38.09
Options vested and expected to vest (in dollars per share)	[1]	53.12
Options vested (in dollars per share)		$ 38.14
Weighted average remaining contractual term, outstanding		6 years 2 months 12 days
Weighted average remaining contractual term, vested and expected to vest	[1]	6 years 1 month 6 days
Weighted average remaining contractual term, vested		4 years 2 months 12 days
Aggregate intrinsic value, outstanding		$ 242.0
Aggregate intrinsic value, vested and expected to vest	[1]	240.5
Aggregate intrinsic value, vested		$ 184.5

[1] For the year ended December 31, 2017, the table excludes the stock award activity for employees of the A&S Business that was divested on October 1, 2018.