Stock Plans and Share-Based Compensation - Stock Option Activity (Details) - Stock Options $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward]
Outstanding beginning of period (in shares) | shares	4,673
Granted (in shares) | shares	1,187
Forfeited (in shares) | shares	(212)
Exercised (in shares) | shares	(1,853)
Outstanding end of period (in shares) | shares	3,795
Exercisable (in shares) | shares	1,026
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding at beginning of period (in dollars per share) | $ / shares	$ 34.89
Granted (in dollars per share) | $ / shares	70.01
Forfeited (in dollars per share) | $ / shares	55.35
Exercised (in dollars per share) | $ / shares	24.48
Outstanding at end of period (in dollars per share) | $ / shares	49.78
Exercisable (in dollars per share) | $ / shares	$ 24.60
Outstanding, weighted-average remaining contractual life (in years)	7 years 6 months
Exercisable, weighted-average remaining contractual life (in years)	6 years
Outstanding, aggregate intrinsic value | $	$ 87
Exercisable, aggregate intrinsic value | $	$ 49