v3.26.1
Financial instruments and related risk management (Measurement of fair values) (Details) - CAD ($)
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Financial assets [Abstract]      
Cash and cash equivalents $ 1,114,860,000 $ 600,462,000 $ 566,809,000
Short-term investments 99,603,000 0  
Accounts receivable 360,312,000 346,800,000  
Derivative assets 21,166,000 103,000  
Financial assets 1,595,941,000 947,365,000  
Financial liabilities [Abstract]      
Accounts payable and accrued liabilities 871,355,000 619,035,000  
Current portion of long-term debt 0 285,707,000  
Lease obligation 14,933,000 9,839,000  
Derivative liabilities 18,921,000 143,609,000  
Long-term debt 996,348,000 995,583,000  
Financial liabilities 1,901,557,000 2,053,773,000  
Net (305,616,000) (1,106,408,000)  
Foreign currency contracts [Member]      
Financial assets [Abstract]      
Derivative assets 21,166,000 103,000  
Financial liabilities [Abstract]      
Derivative liabilities 17,244,000 140,437,000  
Interest rate contracts [Member]      
Financial liabilities [Abstract]      
Derivative liabilities 1,677,000 3,172,000  
Fair value through profit or loss [Member]      
Financial liabilities [Abstract]      
Accounts payable and accrued liabilities 0 0  
Current portion of long-term debt   0  
Lease obligation 0 0  
Long-term debt 0 0  
Financial liabilities 18,921,000 143,609,000  
Net 2,245,000 (143,506,000)  
Fair value through profit or loss [Member] | Foreign currency contracts [Member]      
Financial liabilities [Abstract]      
Derivative liabilities 17,244,000 140,437,000  
Fair value through profit or loss [Member] | Interest rate contracts [Member]      
Financial liabilities [Abstract]      
Derivative liabilities 1,677,000 3,172,000  
Financial liabilities at amortised cost category [Member]      
Financial liabilities [Abstract]      
Accounts payable and accrued liabilities 871,355,000 619,035,000  
Current portion of long-term debt   285,707,000  
Lease obligation 14,933,000 9,839,000  
Long-term debt 996,348,000 995,583,000  
Financial liabilities 1,882,636,000 1,910,164,000  
Net (307,861,000) (962,902,000)  
Financial liabilities at amortised cost category [Member] | Foreign currency contracts [Member]      
Financial liabilities [Abstract]      
Derivative liabilities 0 0  
Financial liabilities at amortised cost category [Member] | Interest rate contracts [Member]      
Financial liabilities [Abstract]      
Derivative liabilities 0 0  
Fair value through profit or loss [Member]      
Financial assets [Abstract]      
Cash and cash equivalents 0 0  
Short-term investments 0    
Accounts receivable 0 0  
Financial assets 21,166,000 103,000  
Fair value through profit or loss [Member] | Foreign currency contracts [Member]      
Financial assets [Abstract]      
Derivative assets 21,166,000 103,000  
Financial assets at amortised cost category [Member]      
Financial assets [Abstract]      
Cash and cash equivalents 1,114,860,000 600,462,000  
Short-term investments 99,603,000    
Accounts receivable 360,312,000 346,800,000  
Financial assets 1,574,775,000 947,262,000  
Financial liabilities [Abstract]      
Net (307,861,000) (962,902,000)  
Financial assets at amortised cost category [Member] | Foreign currency contracts [Member]      
Financial assets [Abstract]      
Derivative assets $ 0 $ 0