v3.26.1
Financial instruments and related risk management (Liquidity Risk Tables) (Details) - CAD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Disclosure of maturity analysis for financial liabilities [abstract]    
Carrying amount $ 1,901,557 $ 2,053,773
Contractual cash flows 1,908,190  
Total interest payments on long-term debt 245,980  
Due in less than one year [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 887,039  
Total interest payments on long-term debt 41,590  
Due in one to three years [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 411,869  
Total interest payments on long-term debt 71,380  
Due in three to five years [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 2,950  
Total interest payments on long-term debt 59,580  
Later Than Five Years [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 606,332  
Total interest payments on long-term debt 73,430  
Accounts Payable And Accrued Liabilities [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Carrying amount 871,355  
Contractual cash flows 871,355  
Accounts Payable And Accrued Liabilities [Member] | Due in less than one year [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 871,355  
Accounts Payable And Accrued Liabilities [Member] | Due in one to three years [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 0  
Accounts Payable And Accrued Liabilities [Member] | Due in three to five years [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 0  
Accounts Payable And Accrued Liabilities [Member] | Later Than Five Years [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 0  
Long-Term Debt [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Carrying amount 996,348  
Contractual cash flows 1,000,000  
Long-Term Debt [Member] | Due in less than one year [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 0  
Long-Term Debt [Member] | Due in one to three years [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 400,000  
Long-Term Debt [Member] | Due in three to five years [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 0  
Long-Term Debt [Member] | Later Than Five Years [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 600,000  
Foreign currency contracts [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Carrying amount 17,244  
Contractual cash flows 17,244  
Foreign currency contracts [Member] | Due in less than one year [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 11,589  
Foreign currency contracts [Member] | Due in one to three years [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 5,655  
Foreign currency contracts [Member] | Due in three to five years [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 0  
Foreign currency contracts [Member] | Later Than Five Years [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 0  
Interest rate swap contracts [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Carrying amount 1,677  
Contractual cash flows 1,677  
Interest rate swap contracts [Member] | Due in less than one year [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 756  
Interest rate swap contracts [Member] | Due in one to three years [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 921  
Interest rate swap contracts [Member] | Due in three to five years [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 0  
Interest rate swap contracts [Member] | Later Than Five Years [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 0  
Lease Obligation [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Carrying amount 14,933  
Contractual cash flows 17,914  
Lease Obligation [Member] | Due in less than one year [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 3,339  
Lease Obligation [Member] | Due in one to three years [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 5,293  
Lease Obligation [Member] | Due in three to five years [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 2,950  
Lease Obligation [Member] | Later Than Five Years [Member]    
Disclosure of maturity analysis for financial liabilities [abstract]    
Contractual cash flows 6,332  
Unsecured revolving credit facility [Member]    
Disclosure of detailed information about borrowings [line items]    
Maximum borrowing capacity 1,000,000  
Committed and outstanding 0  
Available borrowing facility 1,000,000  
Letter of credit facilities [Member]    
Disclosure of detailed information about borrowings [line items]    
Maximum borrowing capacity 1,793,917  
Committed and outstanding 1,529,574  
Available borrowing facility $ 264,343