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Derivatives, Hedging Programs and Other Financial Instruments - Summary of Derivative Positions (Details) mmlb in Millions | 3 Months Ended
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Mar. 31, 2022 EUR (€) mmlb MMBTU MWh
Purchase | Aluminum |
Derivative [Line Items] |
Derivative non-monetary notional amount | 109.3
Purchase | Aluminum | Minimum |
Derivative [Line Items] |
Derivative maturity period | 2022-04
Purchase | Aluminum | Maximum |
Derivative [Line Items] |
Derivative maturity period | 2023-12
Purchase | Midwest premium swap contracts |
Derivative [Line Items] |
Derivative non-monetary notional amount | 92.0
Purchase | Midwest premium swap contracts | Minimum |
Derivative [Line Items] |
Derivative maturity period | 2022-04
Purchase | Midwest premium swap contracts | Maximum |
Derivative [Line Items] |
Derivative maturity period | 2023-12
Purchase | Alloying Metals |
Derivative [Line Items] |
Derivative non-monetary notional amount | 4.8
Purchase | Alloying Metals | Minimum |
Derivative [Line Items] |
Derivative maturity period | 2022-04
Purchase | Alloying Metals | Maximum |
Derivative [Line Items] |
Derivative maturity period | 2022-12
Purchase | Natural Gas |
Derivative [Line Items] |
Derivative non-monetary notional amount | MMBTU | 4,740,000
Purchase | Natural Gas | Minimum |
Derivative [Line Items] |
Derivative maturity period | 2022-04
Purchase | Natural Gas | Maximum |
Derivative [Line Items] |
Derivative maturity period | 2025-12
Purchase | Foreign Exchange Contract |
Derivative [Line Items] |
Derivative notional amount | € | € 138,720
Purchase | Foreign Exchange Contract | Minimum |
Derivative [Line Items] |
Derivative maturity period | 2022-06
Purchase | Foreign Exchange Contract | Maximum |
Derivative [Line Items] |
Derivative maturity period | 2023-03
Purchase | Electricity |
Derivative [Line Items] |
Derivative non-monetary notional amount | MWh | 165,025
Purchase | Electricity | Minimum |
Derivative [Line Items] |
Derivative maturity period | 2022-04
Purchase | Electricity | Maximum |
Derivative [Line Items] |
Derivative maturity period | 2022-12
Sales | Aluminum |
Derivative [Line Items] |
Derivative non-monetary notional amount | 3.0
Sales | Aluminum | Minimum |
Derivative [Line Items] |
Derivative maturity period | 2022-08
Sales | Aluminum | Maximum |
Derivative [Line Items] |
Derivative maturity period | 2022-10

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