Stock-Based Compensation (Summary Of Stock Option Activity) (Detail) (Stock Options [Member], USD $) In Millions, except Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2012
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options, Outstanding at December 31, 2011	8,603,616
Number of Options, Granted	1,044,736
Number of Options, Exercised	(2,630,328)
Number of Options, Forfeited	(120,554)
Number of Options, Outstanding at September 30, 2012	6,897,470
Number of Options, Vested and exercisable at September 30, 2012	3,942,153
Weighted Average Exercise Price, Outstanding at December 31, 2011	$ 9.17
Weighted Average Exercise Price, Granted	$ 37.41
Weighted Average Exercise Price, Exercised	$ 6.89
Weighted Average Exercise Price, Forfeited	$ 14.84
Weighted Average Exercise Price, Outstanding at September 30, 2012	$ 14.25
Weighted Average Exercise Price, Vested and exercisable at September 30, 2012	$ 9.99
Weighted Average Remaining Contractual Term (in years), Outstanding at September 30, 2012	7 years 1 month 21 days
Weighted Average Remaining Contractual Term (in years), Vested and exercisable at September 30, 2012	5 years 11 months 23 days
Aggregate Intrinsic Value, Outstanding at September 30, 2012	$ 290.4	[1]
Aggregate Intrinsic Value, Vested and exercisable at September 30, 2012	$ 182.8	[1]
Closing stock price of common stock	$ 56.35

[1] The aggregate intrinsic value is calculated as the pre-tax difference between the exercise price of the underlying awards and the closing price per share of $56.35 of the Company's common stock on September 28, 2012. The amount is presented in millions.