Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Sep. 30, 2024
Income Tax Disclosure [Abstract]
Income tax provision	$ 7	$ 40	$ 77	$ 68
Effective tax rate	11.00%	89.00%	(51.00%)	99.00%
Unrecognized tax benefits	$ 431		$ 431		$ 422
Unrecognized tax benefits that would impact effective tax rate	110		110		106
Net accrued interest	17		17		$ 21
Interest and penalties accrued	1	$ 2	4	$ 5
Uncertain tax expense position	10		9
Audit closures and statute expirations			17
Audit settlement tax benefit	$ 6		6	$ 17
Adjustment to net operating loss deferred tax assets			19
Deferred tax liability			$ 13