Pension and Other Postretirement Benefits (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jan. 31, 2025	Jan. 31, 2024	Jan. 31, 2025	Jan. 31, 2024
Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Sponsor Location [Extensible List]	United States [Member]	United States [Member]	United States [Member]	United States [Member]
Service cost	$ 4	$ 5	$ 13	$ 14
Interest cost	9	8	27	25
Expected return on plan assets	(10)	(10)	(29)	(30)
Amortization of prior service cost (credit)	0	0	1	0
Amortization of net actuarial loss (gain)	1	2	1	5
Curtailment loss	1	0	1	0
Net cost	$ 5	$ 5	$ 14	$ 14
Other Postretirement Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Sponsor Location [Extensible List]	United States [Member]	United States [Member]	United States [Member]	United States [Member]
Interest cost	$ 0	$ 0	$ 1	$ 1
Special termination benefits	1	0	1	0
Curtailment loss	1	0	1	0
Net cost	$ 2	$ 0	$ 3	$ 1