Accumulated Other Comprehensive Loss - Additional Information (Details) - USD ($) $ in Millions |
Sep. 30, 2024 |
Sep. 30, 2023 |
|---|---|---|
| Equity [Abstract] | ||
| Cumulative income tax benefit on foreign exchange adjustments | $ 3 | $ 1 |
| Cumulative income tax benefit on pension and postretirement benefit plans | 29 | 14 |
| Cumulative income tax expense on derivatives | $ 0 | $ 0 |