v3.26.1
DEBT FACILITIES - Financing Activities (Details) - CAD ($)
$ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Disclosure of reconciliation of liabilities arising from financing activities [line items]    
Liabilities arising from financing activities, beginning $ 3,470.4 $ 3,074.3
Net repayment from borrowing under revolving credit facilities 0.0 (45.0)
Proceeds from long-term debt 89.5 331.5
Repayment of long-term debt (278.9) (321.3)
Repayment of lease liabilities (61.1) (59.9)
Total changes from financing cash flows (250.5) (94.7)
Business combinations (Note 2)   158.5
Foreign currency exchange differences (58.1) 146.1
Additions and remeasurements of lease liabilities 37.4 153.4
Accretion 34.1 32.5
Other 0.9 0.3
Total non-cash changes 14.3 490.8
Liabilities arising from financing activities, end 3,234.2 3,470.4
Unsecured senior notes    
Disclosure of reconciliation of liabilities arising from financing activities [line items]    
Liabilities arising from financing activities, beginning 1,541.4 1,678.3
Net repayment from borrowing under revolving credit facilities 0.0 0.0
Proceeds from long-term debt 0.0 0.0
Repayment of long-term debt (22.1) (216.1)
Repayment of lease liabilities 0.0 0.0
Total changes from financing cash flows (22.1) (216.1)
Business combinations (Note 2)   0.0
Foreign currency exchange differences (35.1) 78.1
Additions and remeasurements of lease liabilities 0.0 0.0
Accretion 0.0 0.0
Other 0.9 1.1
Total non-cash changes (34.2) 79.2
Liabilities arising from financing activities, end 1,485.1 1,541.4
Term loans    
Disclosure of reconciliation of liabilities arising from financing activities [line items]    
Liabilities arising from financing activities, beginning 518.7 239.9
Net repayment from borrowing under revolving credit facilities 0.0 0.0
Proceeds from long-term debt 68.4 285.8
Repayment of long-term debt (217.9) (72.6)
Repayment of lease liabilities 0.0 0.0
Total changes from financing cash flows (149.5) 213.2
Business combinations (Note 2)   48.5
Foreign currency exchange differences (17.2) 16.3
Additions and remeasurements of lease liabilities 0.0 0.0
Accretion 0.0 0.0
Other 0.0 0.8
Total non-cash changes (17.2) 65.6
Liabilities arising from financing activities, end 352.0 518.7
Lease liabilities    
Disclosure of reconciliation of liabilities arising from financing activities [line items]    
Liabilities arising from financing activities, beginning 792.1 551.9
Net repayment from borrowing under revolving credit facilities 0.0 0.0
Proceeds from long-term debt 0.0 0.0
Repayment of long-term debt 0.0 0.0
Repayment of lease liabilities (61.1) (59.9)
Total changes from financing cash flows (61.1) (59.9)
Business combinations (Note 2)   110.0
Foreign currency exchange differences (5.8) 36.7
Additions and remeasurements of lease liabilities 37.4 153.4
Accretion 0.0 0.0
Other (0.4) 0.0
Total non-cash changes 31.2 300.1
Liabilities arising from financing activities, end 762.2 792.1
R&D obligations    
Disclosure of reconciliation of liabilities arising from financing activities [line items]    
Liabilities arising from financing activities, beginning 618.2 574.2
Net repayment from borrowing under revolving credit facilities 0.0 0.0
Proceeds from long-term debt 21.1 45.7
Repayment of long-term debt (38.9) (32.6)
Repayment of lease liabilities 0.0 0.0
Total changes from financing cash flows (17.8) 13.1
Business combinations (Note 2)   0.0
Foreign currency exchange differences 0.0 0.0
Additions and remeasurements of lease liabilities 0.0 0.0
Accretion 34.1 32.5
Other 0.4 (1.6)
Total non-cash changes 34.5 30.9
Liabilities arising from financing activities, end 634.9 618.2
Revolving credit facilities    
Disclosure of reconciliation of liabilities arising from financing activities [line items]    
Liabilities arising from financing activities, beginning 0.0 30.0
Net repayment from borrowing under revolving credit facilities 0.0 (45.0)
Proceeds from long-term debt 0.0 0.0
Repayment of long-term debt 0.0 0.0
Repayment of lease liabilities 0.0 0.0
Total changes from financing cash flows 0.0 (45.0)
Business combinations (Note 2)   0.0
Foreign currency exchange differences 0.0 15.0
Additions and remeasurements of lease liabilities 0.0 0.0
Accretion 0.0 0.0
Other 0.0 0.0
Total non-cash changes 0.0 15.0
Liabilities arising from financing activities, end $ 0.0 $ 0.0