Financial Instruments - Balance Sheet (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	$ (3.1)
Foreign currency contracts [Member]
Derivatives, Fair Value [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	(3.1)
Foreign currency contracts [Member] | Other non-current assets
Derivatives, Fair Value [Line Items]
Derivative assets	0.8	$ 0.0
Foreign currency contracts [Member] | Prepayments and other current assets
Derivatives, Fair Value [Line Items]
Derivative assets	0.9	7.2
Foreign currency contracts [Member] | Accounts payable and accrued expenses
Derivatives, Fair Value [Line Items]
Derivative liabilities	5.0	1.1
Commodity Contract [Member]
Derivatives, Fair Value [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	0.0
Commodity Contract [Member] | Prepayments and other current assets
Derivatives, Fair Value [Line Items]
Derivative assets	0.0	0.1
Commodity Contract [Member] | Accounts payable and accrued expenses
Derivatives, Fair Value [Line Items]
Derivative liabilities	$ 0.0	$ 0.0