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Property, Plant and Mine Development, net (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Property, Plant and Mine Development
Subtotal	$ 121,402		$ 121,162
Accumulated depreciation and amortization	(76,950)		(74,949)
Total	44,452		46,213
Capital expenditures included in accounts payable	200		500
Depreciation and amortization	306	$ 942
Asset retirement costs
Property, Plant and Mine Development
Subtotal	7,665		7,665
Construction-in-progress
Property, Plant and Mine Development
Subtotal	6,074		15,282
Furniture and office equipment
Property, Plant and Mine Development
Subtotal	908		865
Leach pad and ponds
Property, Plant and Mine Development
Subtotal	3,732		3,732
Land
Property, Plant and Mine Development
Subtotal	71		71
Light vehicles and other mobile equipment
Property, Plant and Mine Development
Subtotal	523		523
Machinery and equipment
Property, Plant and Mine Development
Subtotal	47,016		37,819
Process facilities and infrastructure
Property, Plant and Mine Development
Subtotal	10,875		10,667
Mineral interests and mineral rights
Property, Plant and Mine Development
Subtotal	19,828		19,828
Mine development
Property, Plant and Mine Development
Subtotal	24,364		24,364
Software and licenses
Property, Plant and Mine Development
Subtotal	$ 346		$ 346