Divestiture (Details) - USD ($) $ in Millions |
12 Months Ended | |||
|---|---|---|---|---|
Apr. 30, 2021 |
Apr. 30, 2020 |
Apr. 30, 2019 |
Jul. 31, 2020 |
|
| Acquisitions and Divestiture [Abstract] | ||||
| Proceeds from Divestiture of Businesses | $ 177 | $ 0 | $ 0 | |
| Disposal Group, Including Discontinued Operation, Assets | $ 50 | |||
| Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal | $ 127 | $ 0 | $ 0 | |