Financial Instruments (Risk Management Instruments) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Effect from interest rate contracts | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other current liabilities		$ (0.2)
Effect from interest rate contracts | Designated as Hedging Instrument | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other current liabilities		0.0
Effect from interest rate contracts | Designated as Hedging Instrument | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other current liabilities		(0.2)
Effect from interest rate contracts | Designated as Hedging Instrument | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other current liabilities		0.0
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other current liabilities	$ (62.0)	(208.0)
Other noncurrent liabilities	(41.4)	(45.2)
Carrying Amount | Effect from interest rate contracts | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other receivables		0.8
Sundry		35.1
Other current liabilities	(2.7)
Other noncurrent liabilities	(66.5)	(10.5)
Carrying Amount | Cross-currency interest rate swaps | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other receivables	30.3
Sundry	6.9
Other current liabilities	(16.6)	(33.4)
Other noncurrent liabilities		(26.0)
Carrying Amount | Foreign currency exchange contracts | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other receivables	6.3	26.8
Other current liabilities	(14.0)	(36.0)
Estimate of Fair Value Measurement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other current liabilities	(62.0)	(208.0)
Other noncurrent liabilities	(41.4)	(45.2)
Estimate of Fair Value Measurement | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other current liabilities	0.0	0.0
Other noncurrent liabilities	0.0	0.0
Estimate of Fair Value Measurement | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other current liabilities	0.0	0.0
Other noncurrent liabilities	0.0	0.0
Estimate of Fair Value Measurement | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other current liabilities	(62.0)	(208.0)
Other noncurrent liabilities	(41.4)	(45.2)
Estimate of Fair Value Measurement | Effect from interest rate contracts | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other receivables		0.8
Sundry		35.1
Other current liabilities	(2.7)	(0.2)
Other noncurrent liabilities	(66.5)	(10.5)
Estimate of Fair Value Measurement | Effect from interest rate contracts | Designated as Hedging Instrument | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other receivables		0.0
Sundry		0.0
Other current liabilities	0.0
Other noncurrent liabilities	0.0	0.0
Estimate of Fair Value Measurement | Effect from interest rate contracts | Designated as Hedging Instrument | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other receivables		0.8
Sundry		35.1
Other current liabilities	(2.7)
Other noncurrent liabilities	(66.5)	(10.5)
Estimate of Fair Value Measurement | Effect from interest rate contracts | Designated as Hedging Instrument | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other receivables		0.0
Sundry		0.0
Other current liabilities	0.0
Other noncurrent liabilities	0.0	0.0
Estimate of Fair Value Measurement | Cross-currency interest rate swaps | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other receivables	30.3
Sundry	6.9
Other current liabilities	(16.6)	(33.4)
Other noncurrent liabilities		(26.0)
Estimate of Fair Value Measurement | Cross-currency interest rate swaps | Designated as Hedging Instrument | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other receivables	0.0
Sundry	0.0
Other current liabilities	0.0	0.0
Other noncurrent liabilities		0.0
Estimate of Fair Value Measurement | Cross-currency interest rate swaps | Designated as Hedging Instrument | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other receivables	30.3
Sundry	6.9
Other current liabilities	(16.6)	(33.4)
Other noncurrent liabilities		(26.0)
Estimate of Fair Value Measurement | Cross-currency interest rate swaps | Designated as Hedging Instrument | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other receivables	0.0
Sundry	0.0
Other current liabilities	0.0	0.0
Other noncurrent liabilities		0.0
Estimate of Fair Value Measurement | Foreign currency exchange contracts | Not Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other receivables	6.3	26.8
Other current liabilities	(14.0)	(36.0)
Estimate of Fair Value Measurement | Foreign currency exchange contracts | Not Designated as Hedging Instrument | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other receivables	0.0	0.0
Other current liabilities	0.0	0.0
Estimate of Fair Value Measurement | Foreign currency exchange contracts | Not Designated as Hedging Instrument | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other receivables	6.3	26.8
Other current liabilities	(14.0)	(36.0)
Estimate of Fair Value Measurement | Foreign currency exchange contracts | Not Designated as Hedging Instrument | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other receivables	0.0	0.0
Other current liabilities	$ 0.0	$ 0.0