Offsetting Derivative Assets and Liabilities (Details) - USD ($) $ in Millions	Oct. 31, 2021	Apr. 30, 2021
Offsetting Assets and Liabilities [Line Items]
Gross Amount of Derivative Assets	$ 22	$ 10
Gross Amount of Derivative Liabilities Offset Against Derivative Assets in Balance Sheet	(11)	(7)
Net Amount of Derivative Assets Presented in Balance Sheet	11	3
Gross Amount of Derivative Liabilities Not Offset Against Derivative Assets in Balance Sheet	0	(1)
Net Amount of Derivative Assets	11	2
Gross Amount of Derivative Liabilities	(18)	(38)
Gross Amount of Derivative Assets Offset Against Derivative Liabilities in Balance Sheet	11	7
Net Amount of Derivative Liabilities Presented in Balance Sheet	7	31
Gross Amount of Derivative Assets Not Offset Against Derivative Liabilities in Balance Sheet	0	1
Net Amount of Derivative Liabilities	$ 7	$ 30