v3.26.1
Income taxes (Income tax losses carried forward) (Details) - CAD ($)
Dec. 31, 2025
Dec. 31, 2024
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unrecognized deferred tax assets $ 1,634,391,000 $ 1,542,137,000
Unused tax loss carry forward 1,960,169,000 $ 1,827,706,000
Canada [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 702,000  
United States [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 772,252,000  
Other [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 1,187,215,000  
Unused tax expiry 2026 [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 14,830,000  
Unused tax expiry 2026 [Member] | Canada [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2026 [Member] | United States [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2026 [Member] | Other [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 14,830,000  
Unused tax expiry 2027 [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 248,000  
Unused tax expiry 2027 [Member] | Canada [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2027 [Member] | United States [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2027 [Member] | Other [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 248,000  
Unused tax expiry 2028 [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 64,000  
Unused tax expiry 2028 [Member] | Canada [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2028 [Member] | United States [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2028 [Member] | Other [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 64,000  
Unused tax expiry 2029 [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 12,775,000  
Unused tax expiry 2029 [Member] | Canada [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 47,000  
Unused tax expiry 2029 [Member] | United States [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2029 [Member] | Other [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 12,728,000  
Unused tax expiry 2030 [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 2,047,000  
Unused tax expiry 2030 [Member] | Canada [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2030 [Member] | United States [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2030 [Member] | Other [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 2,047,000  
Unused tax expiry 2031 [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 62,763,000  
Unused tax expiry 2031 [Member] | Canada [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2031 [Member] | United States [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 22,040,000  
Unused tax expiry 2031 [Member] | Other [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 40,723,000  
Unused tax expiry 2032 [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 60,650,000  
Unused tax expiry 2032 [Member] | Canada [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 272,000  
Unused tax expiry 2032 [Member] | United States [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 23,738,000  
Unused tax expiry 2032 [Member] | Other [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 36,640,000  
Unused tax expiry 2033 [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 36,485,000  
Unused tax expiry 2033 [Member] | Canada [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2033 [Member] | United States [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 36,485,000  
Unused tax expiry 2033 [Member] | Other [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2034 [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 22,016,000  
Unused tax expiry 2034 [Member] | Canada [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2034 [Member] | United States [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 16,933,000  
Unused tax expiry 2034 [Member] | Other [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 5,083,000  
Unused tax expiry 2035 [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 15,755,000  
Unused tax expiry 2035 [Member] | Canada [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2035 [Member] | United States [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 7,718,000  
Unused tax expiry 2035 [Member] | Other [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 8,037,000  
Unused tax expiry 2036 [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 53,536,000  
Unused tax expiry 2036 [Member] | Canada [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2036 [Member] | United States [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 47,205,000  
Unused tax expiry 2036 [Member] | Other [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 6,331,000  
Unused tax expiry 2037 [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 38,703,000  
Unused tax expiry 2037 [Member] | Canada [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 27,000  
Unused tax expiry 2037 [Member] | United States [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 35,359,000  
Unused tax expiry 2037 [Member] | Other [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 3,317,000  
Unused tax expiry 2038 [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 355,000  
Unused tax expiry 2038 [Member] | Canada [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2038 [Member] | United States [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2038 [Member] | Other [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 355,000  
Unused tax expiry 2039 [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 221,000  
Unused tax expiry 2039 [Member] | Canada [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 66,000  
Unused tax expiry 2039 [Member] | United States [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2039 [Member] | Other [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 155,000  
Unused tax expiry 2040 [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 460,000  
Unused tax expiry 2040 [Member] | Canada [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 37,000  
Unused tax expiry 2040 [Member] | United States [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2040 [Member] | Other [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 423,000  
Unused tax expiry 2041 [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 265,000  
Unused tax expiry 2041 [Member] | Canada [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 77,000  
Unused tax expiry 2041 [Member] | United States [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2041 [Member] | Other [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 188,000  
Unused tax expiry 2042 [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 247,000  
Unused tax expiry 2042 [Member] | Canada [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 49,000  
Unused tax expiry 2042 [Member] | United States [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2042 [Member] | Other [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 198,000  
Unused tax expiry 2043 [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 71,000  
Unused tax expiry 2043 [Member] | Canada [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 71,000  
Unused tax expiry 2043 [Member] | United States [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2043 [Member] | Other [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2044 [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 56,000  
Unused tax expiry 2044 [Member] | Canada [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 56,000  
Unused tax expiry 2044 [Member] | United States [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry 2044 [Member] | Other [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry no expiry [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 1,638,622,000  
Unused tax expiry no expiry [Member] | Canada [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 0  
Unused tax expiry no expiry [Member] | United States [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward 582,774,000  
Unused tax expiry no expiry [Member] | Other [Member]    
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]    
Unused tax loss carry forward $ 1,055,848,000