Percentage Of Forecasted Natural Gas Usage Hedged for Year 1

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- Definition

Aggregate notional amount of price risk derivatives for instruments with notional amounts expressed in percentage of estimated annual domestic (U.S.) usage

+ References

No definition available.

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Aggregate notional amount of price risk derivatives for instruments with notional amounts expressed in percentage of annual estimated usage in production

+ References

No definition available.

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- Definition

Percentage of forecasted natural usage hedged year 3

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No definition available.

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- Definition

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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- Definition

The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=35736893&loc=d3e80748-113994

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- Definition

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5618551-113959

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
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-Section 50
-Paragraph 4C
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-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4D
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624177-113959

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- Definition

The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period.

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- Definition

Nominal mass used to calculate payments on a derivative instrument.

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Derivative Financial Instruments and Hedging (Details) € in Millions, lb in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($) lb	Mar. 31, 2017 USD ($)	Mar. 31, 2018 EUR (€)
Derivative Instruments Gain Loss [Line Items]
Percentage of estimated annual nickel requirements	15.00%
Percentage Of Forecasted Natural Gas Usage Hedged for 2018	35.00%
Percentage Of Forecasted Natural Gas Usage Hedged for 2019	35.00%
Percentage of Forecasted Natural Gas Usage Hedged for 2020	15.00%
Reclassification of Cash Flow Hedge Gain (Loss) [Abstract]
Cash Flow Hedge Gain (Loss) To Be Reclassified Within Twelve Months	$ 8.1
Other Comprehensive Income (Loss) [Member] \| Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Recognized In Other Comprehensive Income Effective Portion Net	2.5	$ (1.5)
Cost Of Sales \| Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Reclassified From Accumulated OCI Into Income Effective Portion Net	$ 2.3	0.6
Nickel
Derivative Instruments Gain Loss [Line Items]
Notional amount of nickel hedge (in pounds of nickel) \| lb	15
Nickel and other raw material contracts \| Other Comprehensive Income (Loss) [Member] \| Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Recognized In Other Comprehensive Income Effective Portion Net	$ 3.1	0.2
Nickel and other raw material contracts \| Cost Of Sales \| Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Reclassified From Accumulated OCI Into Income Effective Portion Net	2.8	(0.6)
Natural gas contracts \| Other Comprehensive Income (Loss) [Member] \| Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Recognized In Other Comprehensive Income Effective Portion Net	0.2	(1.6)
Natural gas contracts \| Cost Of Sales \| Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Reclassified From Accumulated OCI Into Income Effective Portion Net	(0.3)	(1.4)
Foreign exchange contracts \| Other Comprehensive Income (Loss) [Member] \| Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Recognized In Other Comprehensive Income Effective Portion Net	(0.8)	(0.1)
Foreign exchange contracts \| Cost Of Sales \| Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Reclassified From Accumulated OCI Into Income Effective Portion Net	(0.2)	2.6
Designated as Hedging Instrument \| Foreign exchange forward \| Maturity Dates Through 2018 [Member] \| Cash Flow Hedging
Derivative Instruments Gain Loss [Line Items]
Notional amount of derivative \| €			€ 21
Not Designated as Hedging Instrument \| Foreign exchange forward \| Maturity Dates Through 2018 [Member]
Derivative Instruments Gain Loss [Line Items]
Notional amount of derivative \| €			€ 10
Not Designated as Hedging Instrument \| Foreign exchange contracts \| Cost Of Sales
Derivative Instruments Gain Loss [Line Items]
Derivative Instruments Gain Loss Recognized In Income Net	$ (0.2)	$ (0.1)