Compensation Expense for Share-Based Payment Arrangements and Associated Tax Impacts (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Compensation Expense	$ 20.2	$ 18.3	$ 43.3	$ 38.8
Tax Benefits Recognized	7.5	6.8	16.2	14.5
Restricted Stock Unit Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Compensation Expense	14.9	11.9	29.0	24.3
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Compensation Expense	2.1	4.3	8.5	11.2
Performance Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Compensation Expense	$ 3.2	$ 2.1	$ 5.8	$ 3.3