Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions |
Apr. 30, 2021 |
Apr. 30, 2020 |
|---|---|---|
| Deferred tax assets: | ||
| Postretirement and other benefits | $ 90 | $ 110 |
| Accrued liabilities and other | 47 | 23 |
| Inventories | 30 | 26 |
| Lease liabilities | 17 | 14 |
| Derivative instruments | 5 | 0 |
| Loss and credit carryforwards | 63 | 57 |
| Valuation allowance | (20) | (22) |
| Total deferred tax assets, net | 232 | 208 |
| Deferred tax liabilities: | ||
| Intangible assets | (214) | (233) |
| Property, plant, and equipment | (89) | (90) |
| Right-of-use assets | (17) | (13) |
| Derivative instruments | 0 | (18) |
| Other | (11) | (16) |
| Total deferred tax liabilities | (331) | (370) |
| Net deferred tax liability | $ (99) | $ (162) |