Other Expense (Income), Net (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Fixed asset charges	$ 17	$ 2	$ 17	$ 2
Total Sierre flood	61	0	101	0
Currency losses, net	2	1	3	5
Unrealized losses (gains) on change in fair value of derivative instruments, net	(9)	23	(16)	19
Realized (gains) losses on change in fair value of derivative instruments, net	6	(25)	32	(49)
Loss on sale or disposal of assets, net	1	0	2	0
Interest income	(5)	(4)	(13)	(11)
Non-operating net periodic benefit cost	0	(2)	(1)	(3)
Other, net	9	5	17	10
Other expenses (income), net	65	(2)	125	(29)
Sierre flood
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Fixed asset charges	0	0	30	0
Inventory charges	2	0	12	0
Idle fixed costs	16	0	16	0
Repairs and clean-up costs	17	0	17	0
Excess costs to fulfill customer contracts	23	0	23	0
Other	3	0	3	0
Total Sierre flood	$ 61	$ 0	$ 101	$ 0