Derivatives (Details 3) (Fair Value, Inputs, Level 2 [Member], USD $) In Millions, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012
Designated as Hedging Instrument [Member]
Location and amounts of derivative fair values in Consolidated Balance Sheets and derivative gains and losses in Consolidated Statements of Operations
Derivative Asset, Fair Value	$ 0	[1]	$ 1.9	[1]
Derivative Liability, Fair Value	3.9	[1]	0	[1]
Designated as Hedging Instrument [Member] | Commodity Futures Contracts [Member] | Other Current Assets [Member]
Location and amounts of derivative fair values in Consolidated Balance Sheets and derivative gains and losses in Consolidated Statements of Operations
Derivative Asset, Fair Value	0	[1]	1.6	[1]
Designated as Hedging Instrument [Member] | Commodity Futures Contracts [Member] | Other Assets Non Current [Member]
Location and amounts of derivative fair values in Consolidated Balance Sheets and derivative gains and losses in Consolidated Statements of Operations
Derivative Asset, Fair Value	0	[1]	0.3	[1]
Designated as Hedging Instrument [Member] | Commodity Futures Contracts [Member] | Other Liabilities Current [Member]
Location and amounts of derivative fair values in Consolidated Balance Sheets and derivative gains and losses in Consolidated Statements of Operations
Derivative Liability, Fair Value	3.1	[1]	0	[1]
Designated as Hedging Instrument [Member] | Commodity Futures Contracts [Member] | Other Liabilities Non Current [Member]
Location and amounts of derivative fair values in Consolidated Balance Sheets and derivative gains and losses in Consolidated Statements of Operations
Derivative Liability, Fair Value	0.8	[1]	0	[1]
Designated as Hedging Instrument [Member] | Foreign Currency Forward Contracts [Member] | Other Current Assets [Member]
Location and amounts of derivative fair values in Consolidated Balance Sheets and derivative gains and losses in Consolidated Statements of Operations
Derivative Asset, Fair Value	0	[1]	0	[1]
Designated as Hedging Instrument [Member] | Foreign Currency Forward Contracts [Member] | Other Liabilities Current [Member]
Location and amounts of derivative fair values in Consolidated Balance Sheets and derivative gains and losses in Consolidated Statements of Operations
Derivative Liability, Fair Value	0	[1]	0	[1]
Not Designated as Hedging Instrument [Member]
Location and amounts of derivative fair values in Consolidated Balance Sheets and derivative gains and losses in Consolidated Statements of Operations
Derivative Asset, Fair Value	0.4	[1]	0.3	[1]
Derivative Liability, Fair Value	0.6	[1]	0.1	[1]
Not Designated as Hedging Instrument [Member] | Commodity Futures Contracts [Member] | Other Current Assets [Member]
Location and amounts of derivative fair values in Consolidated Balance Sheets and derivative gains and losses in Consolidated Statements of Operations
Derivative Asset, Fair Value	0	[1]	0.2	[1]
Not Designated as Hedging Instrument [Member] | Commodity Futures Contracts [Member] | Other Assets Non Current [Member]
Location and amounts of derivative fair values in Consolidated Balance Sheets and derivative gains and losses in Consolidated Statements of Operations
Derivative Asset, Fair Value	0	[1]	0	[1]
Not Designated as Hedging Instrument [Member] | Commodity Futures Contracts [Member] | Other Liabilities Current [Member]
Location and amounts of derivative fair values in Consolidated Balance Sheets and derivative gains and losses in Consolidated Statements of Operations
Derivative Liability, Fair Value	0.5	[1]	0	[1]
Not Designated as Hedging Instrument [Member] | Commodity Futures Contracts [Member] | Other Liabilities Non Current [Member]
Location and amounts of derivative fair values in Consolidated Balance Sheets and derivative gains and losses in Consolidated Statements of Operations
Derivative Liability, Fair Value	0.1	[1]	0	[1]
Not Designated as Hedging Instrument [Member] | Foreign Currency Forward Contracts [Member] | Other Current Assets [Member]
Location and amounts of derivative fair values in Consolidated Balance Sheets and derivative gains and losses in Consolidated Statements of Operations
Derivative Asset, Fair Value	0.4	[1]	0.1	[1]
Not Designated as Hedging Instrument [Member] | Foreign Currency Forward Contracts [Member] | Other Liabilities Current [Member]
Location and amounts of derivative fair values in Consolidated Balance Sheets and derivative gains and losses in Consolidated Statements of Operations
Derivative Liability, Fair Value	$ 0	[1]	$ 0.1	[1]

[1] All derivative instruments are classified as Level 2 within the fair value hierarchy. See Note 16 for more information.