Derivative Instruments and Hedging Activities - Schedule of Effects of Master Netting Agreements on Condensed Consolidated Balance Sheets (Detail) (Cash flow hedges [Member], USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Other current assets [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amount	$ 57.2	$ 60.2
Offset	10.3	13.5
Net Amount in Balance Sheet	46.9	46.7
Other assets [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amount	30.8	30.2
Offset	6.8	8.2
Net Amount in Balance Sheet	24.0	22.0
Other current liabilities [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amount	12.2	26.4
Offset	10.3	13.5
Net Amount in Balance Sheet	1.9	12.9
Other long-term liabilities [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amount	8.4	15.9
Offset	6.8	8.2
Net Amount in Balance Sheet	$ 1.6	$ 7.7