Summary of Option Activity (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning Balance, Options	8.2	8.3	8.8
Granted, Options	1.7	1.6	1.2
Exercised, Options	(1.0)	(1.5)	(1.6)
Cancelled, Options	(0.1)	(0.2)	(0.1)
Ending Balance, Options	8.8	8.2	8.3
Beginning Balance, Weighted-Average Exercise Price	$ 32.81	$ 26.39	$ 22.63
Exercisable at December 31, 2013, Options	4.5
Granted, Weighted-Average Exercise Price	$ 61.89	$ 53.81	$ 40.60
Exercised, Weighted-Average Exercise Price	$ 21.47	$ 19.00	$ 16.53
Cancelled, Weighted-Average Exercise Price	$ 47.47	$ 35.57	$ 30.22
Ending Balance, Weighted-Average Exercise Price	$ 39.47	$ 32.81	$ 26.39
Exercisable at December 31, 2013, Weighted-Average Exercise Price	$ 26.08
Outstanding at December 31, 2013, Weighted-Average Remaining Contractual Term, years	6 years 2 months 12 days
Exercisable at December 31, 2013, Weighted-Average Remaining Contractual Term, years	4 years 2 months 12 days
Outstanding at December 31, 2013, Aggregate Intrinsic Value	$ 235.8
Exercisable at December 31, 2013, Aggregate Intrinsic Value	$ 180.6