Total Stock Option Activity and Amounts (Detail) (Stock Options, USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares outstanding, beginning balance	5,229,569
Number of shares, granted	665,395
Number of shares, exercised	(1,443,239)
Number of shares, canceled/forfeited	(93,799)
Number of shares outstanding, ending balance	4,357,926
Number of shares, exercisable	2,554,440
Weighted average exercise price, beginning balance	$ 93.30
Weighted average exercise price, granted	$ 167.12
Weighted average exercise price, exercised	$ 82.62
Weighted average exercise price, canceled/forfeited	$ 110.48
Weighted average exercise price, ending balance	$ 107.74
Weighted average exercise price, exercisable	$ 89.59
Weighted average remaining contractual term (years), outstanding, ending balance	6 years 9 months 18 days
Weighted average remaining contractual term (years), exercisable	5 years 3 months 18 days
Aggregate intrinsic value, outstanding, ending balance	$ 258.0
Aggregate intrinsic value, exercisable	$ 196.8