v3.26.1
Other Expense (Income) (Details) - USD ($)
$ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]      
Fixed asset charges $ 92 $ 34 $ 28
Currency losses, net (7) (7) (10)
Unrealized (gains) losses on change in fair value of derivative instruments, net 77 (57) 36
Realized losses (gains) on change in fair value of derivative instruments, net (35) (97) 80
(Gain) loss on sale or disposal of assets, net 5 (4) (6)
Interest income (20) (23) (23)
Non-operating net periodic benefit cost 5 0 3
Other, net 33 31 32
Other expenses (income), net (960) (134) 22
Other nonrecurring expense 10    
Brazil      
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]      
Other, net 15 11  
Fire      
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]      
Fixed asset charges 36 0 0
Inventory charges 1 0 0
Idle fixed costs 115 0 0
Repairs and clean-up costs 251 0 0
Excess costs to fulfill customer contracts 590 0 0
Property insurance recoveries (78) 0 0
Other 10 0 0
September and November Oswego fires losses, net of recoveries 925 0 0
Sierre business interruption insurance recoveries 12 0 0
Sierre flood      
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]      
Fixed asset charges 0 30 0
Inventory charges 0 12 0
Idle fixed costs 0 20 0
Repairs and clean-up costs 13 37 0
Excess costs to fulfill customer contracts 4 35 0
Property insurance recoveries (45) (34) 0
Other 1 5 0
Sierre flood losses, net of recoveries (27) 105 0
Sierre business interruption insurance recoveries $ 41 $ 30 $ 0