v3.26.1
Joint operations (Joint operations proportionate interest in net assets table) (Details) - CAD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Disclosure of joint operations [line items]    
Total assets $ 10,301,282 $ 9,907,007
McArthur River [Member]    
Disclosure of joint operations [line items]    
Ownership 69.81%  
Principal place of business Canada  
Total assets $ 1,011,469 963,183
Total liabilities $ 57,890 53,373
Key Lake [Member]    
Disclosure of joint operations [line items]    
Ownership 83.33%  
Principal place of business Canada  
Total assets $ 516,791 485,635
Total liabilities $ 264,001 248,107
Cigar Lake [Member]    
Disclosure of joint operations [line items]    
Ownership 54.55%  
Principal place of business Canada  
Total assets $ 978,600 1,010,646
Total liabilities 65,569 57,125
Joint Operations [Member]    
Disclosure of joint operations [line items]    
Total assets 2,506,860 2,459,464
Total liabilities $ 387,460 $ 358,605