Goodwill and Other Intangible Assets (Details) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Apr. 30, 2021 |
Apr. 30, 2020 |
|
| Goodwill [Roll Forward] | ||
| Beginning balance | $ 756 | $ 753 |
| Sale of business | (4) | |
| Acquisition of business | 8 | 11 |
| Foreign currency translation adjustment | 19 | (8) |
| Impairment | 0 | |
| Ending balance | 779 | 756 |
| Indefinite-lived Intangible Assets [Roll Forward] | ||
| Beginning balance | 635 | 645 |
| Sale of business | (1) | |
| Acquisition of business | 8 | 12 |
| Foreign currency translation adjustment | 34 | (9) |
| Impairment | (13) | |
| Ending balance | $ 676 | $ 635 |