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Investments (Tables) | 9 Months Ended
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Sep. 30, 2016
Investments Schedule [Abstract] |
Summary of Unaudited Financial Information for Alcoa's Equity Investments | A summary of unaudited financial information for Arconic’s equity investments is as follows (amounts represent 100% of investee financial information):
|  | Third quarter ended September 30, |  |  | Nine months ended September 30, |
|  | 2016 |  |  | 2015 |  |  | 2016 |  |  | 2015 |
Sales |  | $ | 888 |  |  | $ | 1,015 |  |  | $ | 2,684 |  |  | $ | 2,872 |
Cost of goods sold |  |  | 840 |  |  |  | 796 |  |  |  | 2,200 |  |  |  | 2,353 |
Net income (loss) |  |  | (6 | ) |  |  | 20 |  |  |  | 23 |  |  |  | (66 | )

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