Income Taxes - Additional Information (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Jun. 30, 2025 |
Jun. 30, 2024 |
|
Minimum [Member] | ||||
Income Tax Contingency [Line Items] | ||||
Decrease in unrecognized tax benefits is reasonably possible | $ 2 | $ 2 | ||
Maximum [Member] | ||||
Income Tax Contingency [Line Items] | ||||
Decrease in unrecognized tax benefits is reasonably possible | $ 4 | $ 4 | ||
Current Fiscal Year [Member] | ||||
Income Tax Contingency [Line Items] | ||||
Effective tax rate (in hundredths) | 2.00% | (2.00%) | ||
Income tax reconciliation, nondeductible goodwill impairment | $ 706 | $ 706 | ||
Tax (benefit) and expense | $ (16) | $ (23) | ||
Prior Fiscal Year [Member] | ||||
Income Tax Contingency [Line Items] | ||||
Effective tax rate (in hundredths) | (144.00%) | (467.00%) | ||
Tax (benefit) and expense | $ (104) | $ (231) |