Derivative Financial Instruments and Hedging (Details2) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	$ 1.0	$ 6.2
Derivative Fair Value Of Derivative Liability	22.4	11.8
Derivatives designated as hedging instruments:
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	1.0	5.8
Derivative Fair Value Of Derivative Liability	20.8	10.2
Derivatives not designated as hedging instruments:
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0	0.4
Derivative Fair Value Of Derivative Liability	1.6	1.6
Prepaid expenses and other current assets | Nickel and other raw material contracts | Derivatives designated as hedging instruments:
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0	0.6
Prepaid expenses and other current assets | Natural gas contracts | Derivatives designated as hedging instruments:
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0.4	0.4
Prepaid expenses and other current assets | Electricity contracts | Derivatives designated as hedging instruments:
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0	0
Prepaid expenses and other current assets | Foreign exchange contracts | Derivatives designated as hedging instruments:
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0.3	2.9
Prepaid expenses and other current assets | Foreign exchange contracts | Derivatives not designated as hedging instruments:
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0	0.4
Other assets | Nickel and other raw material contracts | Derivatives designated as hedging instruments:
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0.1	0.3
Other assets | Natural gas contracts | Derivatives designated as hedging instruments:
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0.2	0.7
Other assets | Electricity contracts | Derivatives designated as hedging instruments:
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0	0
Other assets | Foreign exchange contracts | Derivatives designated as hedging instruments:
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Asset	0	0.9
Accrued liabilities | Nickel and other raw material contracts | Derivatives designated as hedging instruments:
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	9.3	1.1
Accrued liabilities | Natural gas contracts | Derivatives designated as hedging instruments:
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	2.2	4.4
Accrued liabilities | Electricity contracts | Derivatives designated as hedging instruments:
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	0.4	0.3
Accrued liabilities | Foreign exchange contracts | Derivatives designated as hedging instruments:
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	4.0	1.7
Accrued liabilities | Foreign exchange contracts | Derivatives not designated as hedging instruments:
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	1.6	1.6
Other long-term liabilities | Nickel and other raw material contracts | Derivatives designated as hedging instruments:
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	1.5	0.3
Other long-term liabilities | Natural gas contracts | Derivatives designated as hedging instruments:
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	0.3	0.6
Other long-term liabilities | Electricity contracts | Derivatives designated as hedging instruments:
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	0.1	0.4
Other long-term liabilities | Foreign exchange contracts | Derivatives designated as hedging instruments:
Derivatives Fair Value [Line Items]
Derivative Fair Value Of Derivative Liability	$ 3.0	$ 1.4