v3.26.1
Income Taxes (Narrative) (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Mar. 31, 2026
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Mar. 31, 2023
Income Tax Details [Line Items]          
Deferred tax assets, valuation allowance $ (581) $ (581) $ (628) $ (696) $ (711)
Income tax provision (benefit)   1 159 218  
Net operating loss carryforwards 729 729      
Tax credit carryforward 160 160 152    
Operating loss carryforwards, valuation allowance 359 359 431    
Tax credit carryforward, valuation allowance 99 99 102    
Other deferred taxes, valuation allowance 123 123 95    
Operating loss carryforwards     635    
Undistributed earnings of foreign subsidiaries (outside Canada) 3,000 3,000      
Other deferred tax assets 42 42 38    
Unrecognized tax benefits 74 74 68 80 $ 73
Accrued income tax penalties and interest 8 8 7 9  
Taxes payable 81 81 64    
Taxes payable, current $ 57 57 48    
Tax credits   (34) (35) $ (36)  
Canada Statutory Tax Rate 25.00%        
Income tax penalties and interest expense   1 (2)    
New York          
Income Tax Details [Line Items]          
Income tax credits and adjustments   2      
Deferred tax assets, valuation allowance $ (2) (2)      
China          
Income Tax Details [Line Items]          
Income tax provision (benefit)   10      
Canada          
Income Tax Details [Line Items]          
Income tax credits and adjustments   18      
Deferred tax assets, valuation allowance (340) (340)      
Income tax provision (benefit)   (75) (74)    
Tax credit carryforward 8 8      
Operating loss carryforwards 216 216      
Other deferred tax assets $ 116 $ 116      
Canada Statutory Tax Rate   25.00%      
Brazil          
Income Tax Details [Line Items]          
Income tax provision (benefit)     (13)    
United States          
Income Tax Details [Line Items]          
Income tax credits and adjustments   $ 9      
Italy          
Income Tax Details [Line Items]          
Income tax provision (benefit)     $ 10