v3.25.1
Retirement Benefits (Tables)
 6 Months Ended
Mar. 31, 2025
Retirement Benefits [Abstract]  
Schedule of Net Benefit Costs
The components of net periodic pension and postretirement benefit cost were (in millions):
 Pension Benefits
 Three Months Ended
March 31,		Six Months Ended
March 31,
 2025202420252024
Service cost$11 $9 $21 $19 
Interest cost34 37 68 73 
Expected return on plan assets(42)(43)(83)(85)
Amortization of net actuarial loss7 — 13 — 
Net periodic pension benefit cost$10 $3 $19 $7 
 Other Postretirement Benefits
 Three Months Ended
March 31,		Six Months Ended
March 31,
 2025202420252024
Service cost$— $— $— $— 
Interest cost— — — 1 
Amortization of net actuarial loss1 1 2 1 
Net periodic postretirement benefit cost$1 $1 $2 $2