Intangible Assets - Goodwill (Details) $ in Millions |
9 Months Ended |
---|---|
Sep. 30, 2021
USD ($)
| |
Goodwill [Line Items] | |
Balance at December 31, 2020 | $ 4 |
Additions | 905 |
Balance at September 30, 2021 | 909 |
Flat-Rolled | |
Goodwill [Line Items] | |
Balance at December 31, 2020 | 0 |
Additions | 0 |
Balance at September 30, 2021 | 0 |
Mini Mill | |
Goodwill [Line Items] | |
Balance at December 31, 2020 | 0 |
Additions | 905 |
Balance at September 30, 2021 | 905 |
USSE | |
Goodwill [Line Items] | |
Balance at December 31, 2020 | 4 |
Additions | 0 |
Balance at September 30, 2021 | 4 |
Tubular | |
Goodwill [Line Items] | |
Balance at December 31, 2020 | 0 |
Additions | 0 |
Balance at September 30, 2021 | $ 0 |