Fair Value Measurements - Cash Flow Hedges (Details) (Fair Value, Measurements, Recurring, Cash flow hedges, Foreign currency forward contracts, USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	$ 0	$ 0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	6.1	7.3
Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	$ 0	$ 0