v3.26.1
Fair Value Measurements - Additional Information (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Sep. 30, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Impairment charges $ 0 $ 1 $ 0 $ 4  
Level 2 measurement          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Fair value of debt $ 4,609   $ 4,609   $ 4,270