| Document and Entity Information | Sep. 14, 2022 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Sep. 14, 2022 |
| Entity Registrant Name | Arconic Corp |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-39162 |
| Entity Tax Identification Number | 84-2745636 |
| Entity Address, Address Line One | 201 Isabella Street |
| Entity Address, Address Line Two | Suite 400 |
| Entity Address, City or Town | Pittsburgh |
| Entity Address, State or Province | PA |
| Entity Address, Postal Zip Code | 15212-5872 |
| City Area Code | 412 |
| Local Phone Number | 992-2500 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001790982 |
| Title of 12(b) Security | Common Stock, par value $0.01 per share |
| Trading Symbol | ARNC |
| Security Exchange Name | NYSE |
