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Noncontrolling Interests (Tables) | 12 Months Ended
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Dec. 31, 2012
Schedule of Noncontrolling Shareholders' Interests | The following table summarizes the noncontrolling shareholders’ interests in the equity of Alcoa’s majority-owned consolidated subsidiaries:
December 31, |  | 2012 |  |  | 2011 |
Alcoa World Alumina and Chemicals |  | $ | 3,295 |  |  | $ | 3,324 |
Other |  |  | 29 |  |  |  | 27 |
|  | $ | 3,324 |  |  | $ | 3,351 |

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- Definition Schedule of Noncontrolling Shareholders Interests[Text Block] + References No definition available. + Details
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