Financial Instruments - Balance Sheet (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Foreign currency contracts | Prepayments and other current assets
Derivatives, Fair Value [Line Items]
Derivative assets	$ 3.5	$ 3.4
Foreign currency contracts | Other non-current assets
Derivatives, Fair Value [Line Items]
Derivative assets	0.2	0
Foreign currency contracts | Accounts payable and accrued expenses
Derivatives, Fair Value [Line Items]
Derivative liabilities	2.8	7.4
Foreign currency contracts | Other non-current liabilities
Derivatives, Fair Value [Line Items]
Derivative liabilities	0	0
Net investment hedge contracts | Other non-current assets
Derivatives, Fair Value [Line Items]
Derivative assets	0	0
Net investment hedge contracts | Other non-current liabilities
Derivatives, Fair Value [Line Items]
Derivative liabilities	$ 26.0	$ 24.3