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Derivatives, Hedging Programs and Other Financial Instruments, Material Derivative Positions (Details) - Designated as Hedging Instrument mmlbs in Millions | Jun. 30, 2018 EUR (€) MMBTU MWH mmlbs
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Aluminum | Purchase |
Derivative [Line Items] |
Derivative non-monetary notional amount | 163.4
Aluminum | Sales |
Derivative [Line Items] |
Derivative non-monetary notional amount | 2.4
Midwest premium swap contracts | Purchase |
Derivative [Line Items] |
Derivative non-monetary notional amount | 130.7
Alloy Metal Hedge | Purchase |
Derivative [Line Items] |
Derivative non-monetary notional amount | 6.6
Natural Gas | Purchase |
Derivative [Line Items] |
Derivative non-monetary notional amount | MMBTU | 3,210,000
Electricity | Purchase |
Derivative [Line Items] |
Derivative non-monetary notional amount | MWH | 175,680
Foreign Exchange Contract | Purchase |
Derivative [Line Items] |
Derivative notional amount | € | € 53,324

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- Definition Aggregate notional amount of derivative expressed in nonmonetary units. For example, the number of barrels specified in a fuel oil forward purchase contract. + 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 + Details
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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 + Details
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