Income Taxes (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
Mar. 31, 2026 |
Mar. 31, 2025 |
|
| Income Tax Disclosure [Abstract] | ||||
| Effective income tax rate reconciliation, percent (in percent) | 16.00% | 16.00% | 15.00% | 17.00% |
| Recognized tax expense (benefit) | $ (217) | $ (222) | $ (217) | $ (222) |
| Net tax benefit | 333 | |||
| Tax expense related to resolution of tax matter | $ 71 | $ 71 | ||
| Unrecognized tax benefits, period increase (decrease), gross | 24 | 37 | ||
| Unrecognized tax benefits, period increase (decrease), net | $ 22 | $ 33 | ||
| X | ||||||||||
- Definition Amount of other deferred income tax expense (benefit) pertaining to income (loss) from continuing operations. For example, but not limited to, acquisition-date income tax benefits or expenses recognized from changes in the acquirer's valuation allowance for its previously existing deferred tax assets resulting from a business combination and adjustments to beginning-of-year balance of a valuation allowance because of a change in circumstance causing a change in judgment about the realizability of the related deferred tax asset in future periods. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Amount of other income tax expense (benefit). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of increase (decrease) to previously recorded tax expense. Includes, but is not limited to, significant settlements of income tax disputes, and unusual tax positions or infrequent actions taken by the entity, including tax assessment reversal, and IRS tax settlement. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Unrecognized Tax Benefits, Period Increase (Decrease), Gross No definition available.
|
| X | ||||||||||
- Definition Unrecognized Tax Benefits, Period Increase (Decrease), Net No definition available.
|