v3.25.4
Property Plant and Equipment (Details) - USD ($)
$ in Thousands
 9 Months Ended 12 Months Ended
Sep. 30, 2025
Dec. 31, 2024
Statement [Line Items]    
Property, plant and equipment, carrying value $ 163,384 $ 147,399
Cost [Member]    
Statement [Line Items]    
Cost at beginning 397,827 379,438
Cost, asset additions 31,112 19,809
Cost, asset disposals (31)  
Cost, change in decommissioning provision 614 (1,420)
Cost at ending 429,522 397,827
Accumulated depreciation and depletion [Member]    
Statement [Line Items]    
Accumulated depreciation and depletion at beginning (250,428) (226,337)
Accumulated depreciation and depletion, Depreciation/depletion for the year 15,710 24,091
Accumulated depreciation and depletion at ending (266,138) (250,428)
Mining interests [Member]    
Statement [Line Items]    
Property, plant and equipment, carrying value 105,947 92,979
Mining interests [Member] | Cost [Member]    
Statement [Line Items]    
Cost at beginning 239,625 226,819
Cost, asset additions 20,701 14,226
Cost, asset disposals 0  
Cost, change in decommissioning provision 614 (1,420)
Cost at ending 260,940 239,625
Mining interests [Member] | Accumulated depreciation and depletion [Member]    
Statement [Line Items]    
Accumulated depreciation and depletion at beginning (146,646) (132,474)
Accumulated depreciation and depletion, Depreciation/depletion for the year 8,347 14,172
Accumulated depreciation and depletion at ending (154,993) (146,646)
Plant and equipment [Member]    
Statement [Line Items]    
Property, plant and equipment, carrying value 41,274 38,967
Plant and equipment [Member] | Cost [Member]    
Statement [Line Items]    
Cost at beginning 133,022 128,228
Cost, asset additions 8,137 4,794
Cost, asset disposals 0  
Cost, change in decommissioning provision 0 0
Cost at ending 141,159 133,022
Plant and equipment [Member] | Accumulated depreciation and depletion [Member]    
Statement [Line Items]    
Accumulated depreciation and depletion at beginning (94,055) (85,440)
Accumulated depreciation and depletion, Depreciation/depletion for the year 5,830 8,615
Accumulated depreciation and depletion at ending (99,885) (94,055)
Right-of-use lease assets [Member]    
Statement [Line Items]    
Property, plant and equipment, carrying value 3,504 2,973
Right-of-use lease assets [Member] | Cost [Member]    
Statement [Line Items]    
Cost at beginning 12,474 11,685
Cost, asset additions 2,084 789
Cost, asset disposals (31)  
Cost, change in decommissioning provision 0 0
Cost at ending 14,527 12,474
Right-of-use lease assets [Member] | Accumulated depreciation and depletion [Member]    
Statement [Line Items]    
Accumulated depreciation and depletion at beginning (9,501) (8,223)
Accumulated depreciation and depletion, Depreciation/depletion for the year 1,522 1,278
Accumulated depreciation and depletion at ending (11,023) (9,501)
Corporate office equipment [Member]    
Statement [Line Items]    
Property, plant and equipment, carrying value 190 11
Corporate office equipment [Member] | Cost [Member]    
Statement [Line Items]    
Cost at beginning 237  
Cost, asset additions 190 0
Cost, asset disposals 0  
Cost, change in decommissioning provision 0 0
Cost at ending 427 237
Corporate office equipment [Member] | Accumulated depreciation and depletion [Member]    
Statement [Line Items]    
Accumulated depreciation and depletion at beginning (226) (200)
Accumulated depreciation and depletion, Depreciation/depletion for the year 11 26
Accumulated depreciation and depletion at ending (237) (226)
Non-producing properties [Member]    
Statement [Line Items]    
Property, plant and equipment, carrying value 12,469 12,469
Non-producing properties [Member] | Cost [Member]    
Statement [Line Items]    
Cost at beginning 12,469  
Cost, asset additions 0 0
Cost, asset disposals 0  
Cost, change in decommissioning provision 0 0
Cost at ending 12,469 12,469
Non-producing properties [Member] | Accumulated depreciation and depletion [Member]    
Statement [Line Items]    
Accumulated depreciation and depletion at beginning 0 0
Accumulated depreciation and depletion, Depreciation/depletion for the year 0  
Accumulated depreciation and depletion at ending $ 0 $ 0