v3.26.1
Revenue (Disaggregation) (Details) - CAD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Reportable Segments [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers $ 3,481,933 $ 3,135,772
Uranium [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers 2,873,950 2,676,620
Fuel Services [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers 562,421 459,152
Other Segment [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers 45,562 0
Fixed price Contracts [Member] | Reportable Segments [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers 1,283,499 1,204,849
Fixed price Contracts [Member] | Uranium [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers 724,107 791,701
Fixed price Contracts [Member] | Fuel Services [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers 513,830 413,148
Fixed price Contracts [Member] | Other Segment [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers 45,562 0
Market Price Contracts Member [Member] | Reportable Segments [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers 2,198,434 1,930,923
Market Price Contracts Member [Member] | Uranium [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers 2,149,843 1,884,919
Market Price Contracts Member [Member] | Fuel Services [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers 48,591 46,004
Market Price Contracts Member [Member] | Other Segment [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers 0 0
Americas [Member] | Reportable Segments [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers 1,814,870 1,736,678
Americas [Member] | Uranium [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers 1,388,760 1,401,742
Americas [Member] | Fuel Services [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers 380,548 334,936
Americas [Member] | Other Segment [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers 45,562 0
Europe [Member] | Reportable Segments [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers 889,917 563,773
Europe [Member] | Uranium [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers 733,057 488,718
Europe [Member] | Fuel Services [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers 156,860 75,055
Europe [Member] | Other Segment [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers 0 0
Asia [Member] | Reportable Segments [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers 777,146 835,321
Asia [Member] | Uranium [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers 752,133 786,160
Asia [Member] | Fuel Services [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers 25,013 49,161
Asia [Member] | Other Segment [Member]    
Disclosure Of Disaggregation Of Revenue From Contracts With Customers [line items]    
Revenue From Contracts With Customers $ 0 $ 0