Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Sep. 30, 2025
Income Tax Disclosure [Abstract]
Effective income tax rate	11.70%	16.40%
Income tax liabilities	$ 97		$ 97
Gross unrecognized tax benefits	27		29
Accrued interest and penalties related to unrecognized tax benefits	2		$ 2
Reasonably possible amount of reduction in gross unrecognized tax benefits for the next twelve months	22
Reasonably possible amount of net reduction to income tax provision if unrecognized tax benefits were recognized	$ 23