Pension and Other Postretirement Benefits (Schedule of Components of Other Postretirement Benefit Expense) (Details) - Medical and Life Insurance Benefits [Member] - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Apr. 30, 2026 |
Apr. 30, 2025 |
Apr. 30, 2024 |
|
| Postretirement medical and life insurance benefit expense | |||
| Interest cost | $ 2 | $ 2 | $ 2 |
| Curtailment charge | 0 | 1 | 0 |
| Net cost | $ 2 | $ 3 | $ 2 |
| X | ||||||||||
- Definition Postretirement medical and life insurance benefit expense. No definition available.
|
| X | ||||||||||
- Definition Amount of cost recognized for passage of time related to defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount of net periodic benefit cost (credit) for defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of gain (loss) recognized in net periodic benefit (cost) credit from event reducing expected years of future service of present employees or eliminating accrual of defined benefits for some or all future services of present employees. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Details
|