v3.25.2
Accounting Policies Cash and Cash Equivalents (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Sep. 30, 2024
Jun. 30, 2024
Sep. 30, 2023
Cash and Cash Equivalents [Line Items]        
Cash and Cash Equivalent $ 501 $ 502    
Restricted Cash and Cash Equivalent, Noncurrent 21 21    
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents $ 522 $ 523 $ 521 $ 521