Other Comprehensive Income (Details) - USD ($) $ in Millions		3 Months Ended				6 Months Ended
		Oct. 31, 2022	Jul. 31, 2022	Oct. 31, 2021	Jul. 31, 2021	Oct. 31, 2022	Oct. 31, 2021
Before Tax:
Net other comprehensive income (loss)		$ 9		$ 10		$ 17	$ 26
Tax Effect:
Net other comprehensive income (loss)		(7)		(8)		(14)	(16)
Net of Tax:
Net other comprehensive income (loss)		2	$ 1	2	$ 8	3	10
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Before Tax:
Net gain (loss)		0		(9)		(1)	(17)
Reclassification to earnings		0		0		0	0
Net other comprehensive income (loss)		0		(9)		(1)	(17)
Tax Effect:
Net gain (loss)		(6)		(3)		(10)	(5)
Reclassification to earnings		0		0		0	0
Net other comprehensive income (loss)		(6)		(3)		(10)	(5)
Net of Tax:
Net gain (loss)		(6)		(12)		(11)	(22)
Reclassification to earnings		0		0		0	0
Net other comprehensive income (loss)		(6)		(12)		(11)	(22)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Before Tax:
Net gain (loss)		22		15		36	30
Reclassification to earnings	[1]	(15)		(2)		(23)	1
Net other comprehensive income (loss)		7		13		13	31
Tax Effect:
Net gain (loss)		(4)		(4)		(8)	(7)
Reclassification to earnings	[1]	3		1		5	0
Net other comprehensive income (loss)		(1)		(3)		(3)	(7)
Net of Tax:
Net gain (loss)		18		11		28	23
Reclassification to earnings	[1]	(12)		(1)		(18)	1
Net other comprehensive income (loss)		6		10		10	24
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Before Tax:
Net gain (loss)		0		(1)		0	(1)
Reclassification to earnings	[2]	2		7		5	13
Net other comprehensive income (loss)		2		6		5	12
Tax Effect:
Net gain (loss)		0		0		0	0
Reclassification to earnings	[2]	0		(2)		(1)	(4)
Net other comprehensive income (loss)		0		(2)		(1)	(4)
Net of Tax:
Net gain (loss)		0		(1)		0	(1)
Reclassification to earnings	[2]	2		5		4	9
Net other comprehensive income (loss)		$ 2		$ 4		$ 4	$ 8

[1] Pre-tax amount for each period is classified as sales in the accompanying condensed consolidated statements of operations.

[2] Pre-tax amount for each period is classified as non-operating postretirement expense in the accompanying condensed consolidated statements of operations.