Other Income, Net - Components of Other Income (Expense) (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Mar. 31, 2025 |
Sep. 30, 2024 |
Mar. 31, 2024 |
Jun. 30, 2024 |
|
| Other Income and Expenses [Abstract] | ||||
| Leasing, contract services, and miscellaneous income | $ 3 | $ (2) | ||
| Royalty income | 2 | 2 | ||
| Gain on sales of assets and businesses, net | 1 | 3 | ||
| Exchange (losses) gains, net | (3) | 1 | ||
| Non-operating pension and other post-retirement employee benefit income | 2 | 1 | ||
| Total other income, net | $ 5 | $ 6 | $ 5 | $ 3 |