Derivatives - Schedule of Fair Value of Derivatives Designated and Not Designated as Hedges (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Derivatives Fair Value [Line Items]
Derivatives assets	$ 20.6	$ 1.7
Derivatives liabilities	3.2	10.6
Not Designated as Hedging Instrument | Prepaid Expenses and Other Current Assets
Derivatives Fair Value [Line Items]
Derivatives assets	20.6	0.4
Not Designated as Hedging Instrument | Accrued Liabilities
Derivatives Fair Value [Line Items]
Derivatives liabilities	0.3	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	$ 2.9	$ 9.1