Debt and Other Financing Activities - Summary of Impact of Account Receivable Sales Program on Statements of Condensed Consolidated Comprehensive Income (Loss) (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||||||
|---|---|---|---|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
|||||
| U.S. Accounts Receivable Sales Program [Member] | ||||||||
| Disclosure Of Sales Program Of Receivable [Line Items] | ||||||||
| Loss on sale | [1],[2] | $ 0 | $ 1 | $ 1 | $ 3 | |||
| Foreign Accounts Receivable Sales Program [Member] | ||||||||
| Disclosure Of Sales Program Of Receivable [Line Items] | ||||||||
| Loss on sale | [1],[2] | $ 1 | $ 0 | $ 2 | $ 3 | |||
| ||||||||