Information Regarding Intrinsic Value of Stock Options Exercised and Stock Compensation Expense Related to Stock Option Awards (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic Value of Stock Options Exercised	$ 14.5	$ 23.1	$ 25.9	$ 34.0
Stock Compensation Expense Related to Stock Option Awards	9.8	6.5	11.4	7.7
Issued Stock Options	1.6	1.5	1.6	1.5
Weighted Average Fair Value of Stock Options issued (per share)	$ 10.90	$ 8.93	$ 10.90	$ 8.92
Fair Value of Stock Options Issued	$ 17.3	$ 13.7	$ 17.3	$ 13.7