Derivatives - Schedule of Fair Value of Derivatives Designated and Not Designated as Hedges (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Not Designated as Hedging Instrument | Prepaid Expenses and Other Current Assets
Derivatives Fair Value [Line Items]
Derivatives assets	$ 37.2	$ 7.0
Not Designated as Hedging Instrument | Accrued Liabilities
Derivatives Fair Value [Line Items]
Derivatives liabilities	0.3	0.5
Designated Fair Value Hedges | Other Noncurrent Assets
Derivatives Fair Value [Line Items]
Derivatives assets	1.0
Designated Fair Value Hedges | Other Non-current Liabilities
Derivatives Fair Value [Line Items]
Derivatives liabilities		$ 1.2