Cover |
12 Months Ended |
|---|---|
Dec. 31, 2025 | |
| Document Information [Line Items] | |
| Document Type | 11-K |
| Entity Registrant Name | ATI Inc. |
| Amendment Flag | false |
| Entity Central Index Key | 0001018963 |
| EBP 005 | |
| Document Information [Line Items] | |
| Document Type | 11-K |
| Entity Registrant Name | ATI Inc. |
| Amendment Flag | false |
| Entity Central Index Key | 0001018963 |