v3.26.1
INTANGIBLE ASSETS - Narrative (Details) - CAD ($)
$ in Millions
12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Bottom of range    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Discount rate (in percent) 8.40%  
Top of range    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Discount rate (in percent) 9.70%  
Civil Aviation, and Defense and Security    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Growth rate used to extrapolate cash flow projections (in years) 5 years  
Estimated growth rate (in percent) 2.00%  
Civil Aviation, and Defense and Security | Revenue    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Percentage of reasonably possible decrease in unobservable input, assets 1.00%  
Civil Aviation, and Defense and Security | Financial forecast of profit (loss) for cash-generating unit    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Percentage of reasonably possible decrease in unobservable input, assets 1.00%  
Civil Aviation, and Defense and Security | Discount rate    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Percentage of reasonably possible increase in unobservable input, assets 1.00%  
Cost of sales    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Amortization $ 108.6 $ 97.7
Research and development expenses    
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]    
Amortization $ 49.0 $ 34.8