No definition available.

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- Definition

The number of labor unions representing a group of employees.

+ References

No definition available.

+ Details

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- Definition

The percentage of a Company's work force, based in the country of domicile, that are subject to collective bargaining agreements.

+ References

No definition available.

+ Details

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- Definition

The percentage of a Company's Icelandic work force that are subject to collective bargaining agreements.

+ References

No definition available.

+ Details

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- Definition

The percentage of a Company's work force that are subject to collective bargaining agreements.

+ References

No definition available.

+ Details

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- Definition

The power currently available under the power purchase agreement.

+ References

No definition available.

+ Details

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- Definition

Power Supply Agreement, Percentage

+ References

No definition available.

+ Details

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- Definition

Power Supply Agreement, Term

+ References

No definition available.

+ Details

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- Definition

Power Supply Agreement, Termination Notice Period

+ References

No definition available.

+ Details

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- Definition

Power Supply Agreement, Total Production, Percentage

+ References

No definition available.

+ Details

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- Definition

Short-term Power Agreement, Supply from Third Party, Percentage

+ References

No definition available.

+ Details

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- Definition

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.

+ References

No definition available.

+ Details

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Commitments and Contingencies - Other Commitments (Details)	12 Months Ended
	Dec. 31, 2020 labor_union MW	Apr. 01, 2021
Labor Commitments [Abstract]
Percentage of Company's work force represented by a union	67.00%
Percentage of Grundartangi work force represented by the labor unions	86.00%
Number of labor unions under new agreement \| labor_union	5
Percentage of U.S. based work force represented by a union	58.00%
Netherlands [Member]
Labor Commitments [Abstract]
Percentage of Company's work force represented by a union	100.00%
Hawesville [Member]
Loss Contingencies [Line Items]
Power supply agreement, termination notice period	1 year
Sebree [Member]
Loss Contingencies [Line Items]
Power supply agreement, termination notice period	1 year
Mt. Holly [Member] \| Century Aluminum of South Carolina, Inc [Member]
Loss Contingencies [Line Items]
Short-term power agreement, supply from third party (percent)	75.00%
Mt. Holly [Member] \| Santee Cooper [Member]
Loss Contingencies [Line Items]
Short-term power agreement, supply from third party (percent)	25.00%
Power supply agreement, term	3 years
Total production (percent)	75.00%
Mt. Holly [Member] \| Santee Cooper [Member] \| Forecast [Member]
Loss Contingencies [Line Items]
Power supply agreement (percent)		100.00%
Grundartangi - HS, Landsvirkjun and OR [Member]
Loss Contingencies [Line Items]
Power available	525
Grundartangi - Landsvirkjun [Member]
Loss Contingencies [Line Items]
Power available	161
Helguvik [Member]
Loss Contingencies [Line Items]
Power available	47.5