Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	$ 8.5	$ 8.2
Assets, Fair Value, Total	11.1	14.1
Liabilities, Fair Value, Total	15.7	8.3
Hedging contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Fair Value	2.6	5.9
Derivative Liabilities, Fair Value	15.7	8.3
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	8.5	8.2
Assets, Fair Value, Total	8.5	8.2
Liabilities, Fair Value, Total
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Hedging contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liabilities, Fair Value
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value, Total	2.6	5.9
Liabilities, Fair Value, Total	15.7	8.3
Significant Other Observable Inputs (Level 2) [Member] | Hedging contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Fair Value	2.6	5.9
Derivative Liabilities, Fair Value	15.7	8.3
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities
Assets, Fair Value, Total
Liabilities, Fair Value, Total
Significant Unobservable Inputs (Level 3) [Member] | Hedging contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets, Fair Value
Derivative Liabilities, Fair Value