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	Jun. 30, 2014	Dec. 31, 2013
Other current assets [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amount	$ 36.9	$ 60.2
Offset	10.8	13.5
Net Amount in Balance Sheet	26.1	46.7
Other assets [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amount	9.9	30.2
Offset	5.7	8.2
Net Amount in Balance Sheet	4.2	22.0
Other current liabilities [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amount	22.5	26.4
Offset	10.8	13.5
Net Amount in Balance Sheet	11.7	12.9
Other long-term liabilities [Member]
Derivatives And Hedging Activities [Line Items]
Gross Amount	11.1	15.9
Offset	5.7	8.2
Net Amount in Balance Sheet	$ 5.4	$ 7.7