Derivatives (Fair Value of Derivative Instruments) (Details) - Fair Value, Inputs, Level 2 [Member] - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total Assets	$ 0.5	$ 11.7
Total Liabilities	5.5	0.3
Designated as Hedging Instrument [Member] | Commodity Futures Contracts [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Total Assets	0.0	11.0
Designated as Hedging Instrument [Member] | Commodity Futures Contracts [Member] | Other Non-Current Assets [Member]
Derivatives, Fair Value [Line Items]
Total Assets	0.0	0.6
Designated as Hedging Instrument [Member] | Commodity Futures Contracts [Member] | Accrued Expenses [Member]
Derivatives, Fair Value [Line Items]
Total Liabilities	5.2	0.0
Designated as Hedging Instrument [Member] | Commodity Futures Contracts [Member] | Other Non-Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Total Liabilities	0.3	0.0
Designated as Hedging Instrument [Member] | Foreign Currency Forward Contracts [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Total Assets	0.5	0.1
Designated as Hedging Instrument [Member] | Foreign Currency Forward Contracts [Member] | Accrued Expenses [Member]
Derivatives, Fair Value [Line Items]
Total Liabilities	0.0	0.3
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total Assets	0.0	2.2
Total Liabilities	0.4	1.1
Not Designated as Hedging Instrument [Member] | Commodity Futures Contracts [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Total Assets	0.0	1.2
Not Designated as Hedging Instrument [Member] | Commodity Futures Contracts [Member] | Other Non-Current Assets [Member]
Derivatives, Fair Value [Line Items]
Total Assets	0.0	0.1
Not Designated as Hedging Instrument [Member] | Commodity Futures Contracts [Member] | Accrued Expenses [Member]
Derivatives, Fair Value [Line Items]
Total Liabilities	0.3	0.0
Not Designated as Hedging Instrument [Member] | Commodity Futures Contracts [Member] | Other Non-Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Total Liabilities	0.0	0.0
Not Designated as Hedging Instrument [Member] | Foreign Currency Forward Contracts [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Total Assets	0.0	0.9
Not Designated as Hedging Instrument [Member] | Foreign Currency Forward Contracts [Member] | Accrued Expenses [Member]
Derivatives, Fair Value [Line Items]
Total Liabilities	$ 0.1	$ 1.1