v3.25.2
Defined Benefit Pension and Other Postretirement Plans (Details) - Pension Plan - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Defined Benefit Plan Disclosure        
Service cost $ 2 $ 2 $ 7 $ 6
Interest cost 9 9 26 27
Expected return on plan assets (12) (11) (36) (33)
Amortization of:        
Actuarial loss (gain) 1 0 3 1
Net benefit cost (income) $ 0 $ 0 $ 0 $ 1