v3.26.1
Summary of Significant Accounting Policies - Schedule of Cash and Restricted Cash (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Sep. 30, 2025
Jun. 30, 2025
Sep. 30, 2024
Accounting Policies [Abstract]        
Cash and cash equivalents $ 476 $ 335 $ 350  
Restricted cash 47 20 20  
Cash, cash equivalents and restricted cash $ 523 $ 355 $ 370 $ 228