v3.25.4
Consolidation (Details) - USD ($)
$ in Millions
 9 Months Ended
Dec. 31, 2025
Mar. 31, 2025
Dec. 31, 2024
Current assets:      
Cash and cash equivalents $ 825 $ 1,036 $ 791
Inventories 3,703 3,054  
Prepaid expenses and other current assets 302 234  
Total current assets 7,151 6,715  
Property, plant and equipment, net 8,118 6,851  
Goodwill 1,080 1,074  
Deferred income tax assets 166 188  
Total assets 18,246 16,515  
Current liabilities:      
Accrued expenses and other current liabilities 704 666  
Total current liabilities 5,612 5,114  
Accrued postretirement benefits 523 534  
Other long-term liabilities 298 284  
Total liabilities 12,939 12,000  
Primary Beneficiary      
Current assets:      
Cash and cash equivalents 11 4  
Accounts receivable, net 10 9  
Inventories 127 129  
Prepaid expenses and other current assets 13 8  
Total current assets 161 150  
Property, plant and equipment, net 49 101  
Goodwill 12 12  
Deferred income tax assets 33 36  
Other long-term assets 4 3  
Total assets 259 302  
Current liabilities:      
Accounts payable 114 134  
Accrued expenses and other current liabilities 27 37  
Total current liabilities 141 171  
Accrued postretirement benefits 79 102  
Other long-term liabilities 4 2  
Total liabilities $ 224 $ 275  
Logan Aluminum Inc.      
Current liabilities:      
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage 40.00%