Derivative Financial Instruments and Hedging (Details2) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	$ 11.0	$ 6.2
Derivative Fair Value Of Derivative Liability	17.6	11.8
[DesignatedAsHedgingInstrumentMember]
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	10.8	5.8
Derivative Fair Value Of Derivative Liability	16.9	10.2
[NondesignatedMember]
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0.2	0.4
Derivative Fair Value Of Derivative Liability	0.7	1.6
[PrepaidExpensesAndOtherCurrentAssetsMember] | [NickelAndOtherRawMaterialContractsMember] | [DesignatedAsHedgingInstrumentMember]
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0	0.6
[PrepaidExpensesAndOtherCurrentAssetsMember] | [ForeignExchangeContractMember] | [DesignatedAsHedgingInstrumentMember]
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	5.0	2.9
[PrepaidExpensesAndOtherCurrentAssetsMember] | [ForeignExchangeContractMember] | [NondesignatedMember]
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0.2	0.4
[PrepaidExpensesAndOtherCurrentAssetsMember] | [NaturalGasContractsMember] | [DesignatedAsHedgingInstrumentMember]
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0.2	0.4
[PrepaidExpensesAndOtherCurrentAssetsMember] | [ElectricityContractsMember] | [DesignatedAsHedgingInstrumentMember]
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0	0
[OtherAssetsMember] | [NickelAndOtherRawMaterialContractsMember] | [DesignatedAsHedgingInstrumentMember]
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0	0.3
[OtherAssetsMember] | [ForeignExchangeContractMember] | [DesignatedAsHedgingInstrumentMember]
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	5.5	0.9
[OtherAssetsMember] | [NaturalGasContractsMember] | [DesignatedAsHedgingInstrumentMember]
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0.1	0.7
[OtherAssetsMember] | [ElectricityContractsMember] | [DesignatedAsHedgingInstrumentMember]
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0	0
[AccruedLiabilitiesMember] | [NickelAndOtherRawMaterialContractsMember] | [DesignatedAsHedgingInstrumentMember]
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	11.2	1.1
[AccruedLiabilitiesMember] | [ForeignExchangeContractMember] | [DesignatedAsHedgingInstrumentMember]
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	0	1.7
[AccruedLiabilitiesMember] | [ForeignExchangeContractMember] | [NondesignatedMember]
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	0.7	1.6
[AccruedLiabilitiesMember] | [NaturalGasContractsMember] | [DesignatedAsHedgingInstrumentMember]
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	2.9	4.4
[AccruedLiabilitiesMember] | [ElectricityContractsMember] | [DesignatedAsHedgingInstrumentMember]
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	0.2	0.3
[OtherLiabilitiesMember] | [NickelAndOtherRawMaterialContractsMember] | [DesignatedAsHedgingInstrumentMember]
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	1.9	0.3
[OtherLiabilitiesMember] | [ForeignExchangeContractMember] | [DesignatedAsHedgingInstrumentMember]
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	0	1.4
[OtherLiabilitiesMember] | [NaturalGasContractsMember] | [DesignatedAsHedgingInstrumentMember]
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	0.5	0.6
[OtherLiabilitiesMember] | [ElectricityContractsMember] | [DesignatedAsHedgingInstrumentMember]
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	$ 0.2	$ 0.4