v3.26.1
Pension and Other Postretirement Benefits (Change in Benefit Obligation) (Details) - USD ($)
$ in Millions
12 Months Ended
Apr. 30, 2026
Apr. 30, 2025
Apr. 30, 2024
Pension Benefits [Member]      
Changes in present value of pension and other postretirement benefits      
Obligation at beginning of year $ 683 $ 679  
Service cost 14 16 $ 18
Interest cost 30 35 34
Net actuarial loss (gain) [1] (2) 5  
Plan amendments 9 0  
Retiree contributions 0 0  
Benefits paid (119) (52)  
Special termination benefits 0 0  
Obligation at end of year 615 683 679
Medical and Life Insurance Benefits [Member]      
Changes in present value of pension and other postretirement benefits      
Obligation at beginning of year 39 36  
Service cost 0 0  
Interest cost 2 2 2
Net actuarial loss (gain) [1] 0 3  
Plan amendments 0 0  
Retiree contributions 3 2  
Benefits paid (7) (5)  
Special termination benefits 0 1  
Obligation at end of year $ 37 $ 39 $ 36
[1] The net actuarial loss (gain) during each year was primarily attributable to changes in discount rates