v3.26.1
ACCOUNTS RECEIVABLE - Accounts receivable (Details) - CAD ($)
$ in Millions
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Disclosure of financial assets [line items]      
Total trade receivables $ 404.9 $ 442.0  
Investment in finance leases (Note 15) 21.0 16.0  
Receivables from related parties (Note 16) 152.8 61.2  
Other receivables 68.0 114.1  
Total accounts receivable 624.3 612.0  
Gross carrying amount | Current trade receivables      
Disclosure of financial assets [line items]      
Total trade receivables 233.5 256.3  
Gross carrying amount | 1-30 days      
Disclosure of financial assets [line items]      
Total trade receivables 71.4 68.9  
Gross carrying amount | 31-60 days      
Disclosure of financial assets [line items]      
Total trade receivables 22.6 18.1  
Gross carrying amount | 61-90 days      
Disclosure of financial assets [line items]      
Total trade receivables 12.7 15.1  
Gross carrying amount | Greater than 90 days      
Disclosure of financial assets [line items]      
Total trade receivables 64.7 83.6  
Accumulated impairment      
Disclosure of financial assets [line items]      
Credit loss allowances (22.4) (21.3)  
Accumulated impairment | Accounts receivable      
Disclosure of financial assets [line items]      
Credit loss allowances $ (22.4) $ (21.3) $ (20.9)