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v3.19.3

Other Expense, Net - Narrative (Details) - Alcoa Corporation - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2019 | Sep. 30, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |
Tax agreement, indemnification of ultimate liability, percent | 49.00% |
Spain | Other, net |  |
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |
Tax agreement, indemnification, receivable | $ 29 | $ 29
Tax agreement, indemnification of ultimate liability, percent | 49.00% |

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