Gain on Sale of Business (Details) - USD ($) $ in Millions	3 Months Ended
Jul. 31, 2020	Jul. 31, 2019
Gain on Sale of Business [Abstract]
Proceeds from Divestiture of Businesses	$ 177	$ 0
Disposal Group, Including Discontinued Operation, Assets	50
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	$ 127	$ 0

Amount classified as assets attributable to disposal group held for sale or disposed of.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant