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Properties, Plants, and Equipment, Net - Additional Information (Details) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Jun. 30, 2019 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Property, Plant and Equipment [Line Items] |  |  |  |
Asset impairment charges |  | $ 5 | $ 442 | $ 9
Depreciation |  | $ 236 | $ 234 | $ 253
Arconic Engines |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |
Asset impairment charges | $ 428 |  |  |
Arconic Engines | Property, Plant and Equipment |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |
Asset impairment charges | 198 |  |  |
Arconic Engines | Indefinite-lived Intangible Assets |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |
Asset impairment charges | 197 |  |  |
Arconic Engines | Other Noncurrent Assets |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |
Asset impairment charges | 33 |  |  |
Arconic Engines | Engine Products |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |
Asset impairment charges | 247 |  |  |
Arconic Engines | Engineered Structurs Segments |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |
Asset impairment charges | $ 181 |  |  |

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