Share-Based Compensation - Summary of Stock Option Activity (Detail) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) $ / shares shares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Outstanding stock options, Beginning balance | shares	7,931
Options granted | shares	2,109
Options exercised | shares	(1,786)
Options forfeited | shares	(312)
Options expired | shares	(41)
Outstanding stock options, Ending Balance | shares	7,901
Number of outstanding options, Vested or expected to vest | shares	7,377
Exercisable, Stock options | shares	4,316
Outstanding Weighted average exercise price, Beginning Balance | $ / shares	$ 78.73
Options granted, Weighted average exercise price | $ / shares	105.97
Options exercised, Weighted average exercise price | $ / shares	73.37
Options forfeited, Weighted average exercise price | $ / shares	104.58
Options expired, Weighted average exercise price | $ / shares	83.00
Outstanding Weighted average exercise price, ending Balance | $ / shares	86.21
Outstanding Weighted average exercise price, Vested or expected to vest | $ / shares	84.90
Exercisable, Weighted average exercise price | $ / shares	$ 72.23
Weighted Average Remaining Contractual Life, Outstanding at December 31, 2016	6 years 2 months 12 days
Weighted Average Remaining Contractual Life, Vested or expected to vest as of December 31, 2016	6 years
Weighted Average Remaining Contractual Life, Exercisable at December 31, 2016	4 years 1 month 6 days
Intrinsic Value, Outstanding at December 31, 2016 | $	$ 149.6
Intrinsic Value, Vested or expected to vest as of December 31, 2016 | $	148.4
Intrinsic Value, Exercisable at December 31, 2016 | $	$ 136.6