Pension and Other Postretirement Benefits (Details) - Pension Benefits [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jan. 31, 2024	Jan. 31, 2023	Jan. 31, 2024	Jan. 31, 2023
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Sponsor Location [Extensible List]
Service cost	$ 5	$ 5	$ 14	$ 16
Interest cost	8	8	25	24
Expected return on plan assets	(10)	(11)	(30)	(33)
Amortization of prior service cost (credit)	0	0	0	1
Amortization of net actuarial loss (gain)	2	2	5	7
Settlement loss	0	27	0	27
Net cost	$ 5	$ 31	$ 14	$ 42