v3.26.1
Retirement Benefits (Tables)
 6 Months Ended
Mar. 31, 2026
Retirement Benefits [Abstract]  
Schedule of Net Periodic Pension and Postretirement Benefit Cost
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,
 2026202520262025
Service cost$9 $11 $18 $21 
Interest cost35 34 69 68 
Expected return on plan assets(43)(42)(85)(83)
Amortization of net actuarial loss4 7 8 13 
Net periodic pension benefit cost$5 $10 $10 $19 
 Other Postretirement Benefits
 Three Months Ended
March 31,
Six Months Ended
March 31,
 2026202520262025
Service cost$1 $— $1 $— 
Interest cost1 — 1 — 
Amortization of net actuarial loss— 1 1 2 
Net periodic postretirement benefit cost$2 $1 $3 $2