v3.26.1
Income Taxes (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2026
Mar. 31, 2025
Sep. 30, 2025
Income Tax Disclosure [Abstract]          
Effective income tax rate 20.20% 17.10% 16.50% 16.80%  
Income tax liabilities $ 97   $ 97    
Gross unrecognized tax benefits 28   28   $ 29
Accrued interest and penalties related to unrecognized tax benefits 3   3   $ 2
Reasonably possible amount of reduction in gross unrecognized tax benefits for the next twelve months 22   22    
Reasonably possible amount of net reduction to income tax provision if unrecognized tax benefits were recognized $ 23   $ 23