Research and Development (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | 48 Months Ended | ||
|---|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Jun. 30, 2025 |
Jun. 30, 2024 |
Sep. 30, 2026 |
|
| Research and Development Arrangement, Contract to Perform for Others [Line Items] | |||||
| Other Research and Development Expense | $ 0 | $ 12 | $ 10 | $ 29 | |
| Amount of letters of credit outstanding | $ 6 | $ 6 | |||
| Forecast | |||||
| Research and Development Arrangement, Contract to Perform for Others [Line Items] | |||||
| Other Research and Development Expense | $ 93 | ||||