Debt and Other Financing Activities - Summary of Long-term Debt (Details) - USD ($) $ in Millions |
Jun. 30, 2025 |
Sep. 30, 2024 |
||
|---|---|---|---|---|
| Debt Instrument [Line Items] | ||||
| Carrying value of debt | $ 1,392 | $ 1,361 | ||
| Other | [1] | (7) | (8) | |
| Long-term debt (less debt issuance costs) | 1,382 | 1,349 | ||
| 3.375% Senior Notes, due 2031 [Member] | ||||
| Debt Instrument [Line Items] | ||||
| Carrying value of debt | 450 | 450 | ||
| 2.00% Senior Notes Due 2028 [Member] | ||||
| Debt Instrument [Line Items] | ||||
| Carrying value of debt | 586 | 558 | ||
| 6.875% Notes due 2043 [Member] | ||||
| Debt Instrument [Line Items] | ||||
| Carrying value of debt | 282 | 282 | ||
| 6.50% Junior Subordinated Notes, Due 2029 [Member] | ||||
| Debt Instrument [Line Items] | ||||
| Carrying value of debt | $ 71 | $ 67 | ||
| ||||
| X | ||||||||||
- Definition Other short term and long term debt. No definition available.
|
| X | ||||||||||
- Definition Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|