Debt Short-term Borrowings (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
Jan. 31, 2022	Apr. 30, 2021
Short-term Debt [Abstract]
Short-term borrowings	$ 16	$ 205
Commercial Paper	$ 0	$ 195
Commercial Paper, Weighted Average Interest Rate, at Point in Time	0.00%	0.16%
Commercial Paper Borrowings, Average Remaining Maturity	0 days	24 days

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

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