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Business acquisitions - Acquisition of Mt. Holly smelter narrative other units (Details) t in Thousands | Dec. 01, 2014 employee t | Nov. 30, 2014
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Mt. Holly Smelter [Member] |  |
Business Acquisition [Line Items] |  |
Remaining percentage acquired in step acquisition |  | 50.30%
Percentage of ownership after step acquisition | 100.00% |
Employees | employee | 600 |
Mt Holly primary aluminum capacity (tonnes) | t | 231 |
Mt. Holly [Member] | Berkeley Aluminum Inc. [Member] |  |
Business Acquisition [Line Items] |  |
Ownership percentage |  | 49.70%

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- Details
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