Derivatives - Schedule of Fair Value of Derivatives Designated and Not Designated as Hedges (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Not Designated as Hedging Instrument | Prepaid Expenses and Other Current Assets
Derivatives Fair Value [Line Items]
Derivatives assets	$ 7.0	$ 0.4
Not Designated as Hedging Instrument | Accrued Liabilities
Derivatives Fair Value [Line Items]
Derivatives liabilities	0.5	1.5
Designated Fair Value Hedges | Prepaid Expenses and Other Current Assets
Derivatives Fair Value [Line Items]
Derivatives assets		1.3
Designated Fair Value Hedges | Other Non-current Liabilities
Derivatives Fair Value [Line Items]
Derivatives liabilities	$ 1.2	$ 9.1