Property, plant, and equipment and assets held-for-sale, net - Schedule of Components of Plant and Equipment, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 88,566	$ 88,441
Less, accumulated depreciation and amortization	(38,453)	(38,329)
Total property, plant, and equipment, net	50,113	50,112
Assets held-for-sale	2,893	2,893
Total	53,006	53,005
Process equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	18,029	18,029
Production leach pads
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 11,190	11,190
Buildings and leasehold improvements
Property, Plant and Equipment [Line Items]
Depreciation Life or Method	10 years
Property, plant and equipment, gross	$ 9,086	9,536
Test leach pads
Property, Plant and Equipment [Line Items]
Depreciation Life or Method	18 months
Property, plant and equipment, gross	$ 6,241	6,241
Mine equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	5,143	5,143
Vehicles
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 1,854	1,854
Furniture and office equipment
Property, Plant and Equipment [Line Items]
Depreciation Life or Method	7 years
Property, plant and equipment, gross	$ 1,141	1,141
Mineral properties
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	50	50
Construction in progress and other
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 35,832	$ 35,257
Minimum | Process equipment
Property, Plant and Equipment [Line Items]
Depreciation Life or Method	5 years
Minimum | Mine equipment
Property, Plant and Equipment [Line Items]
Depreciation Life or Method	5 years
Minimum | Vehicles
Property, Plant and Equipment [Line Items]
Depreciation Life or Method	3 years
Maximum | Process equipment
Property, Plant and Equipment [Line Items]
Depreciation Life or Method	15 years
Maximum | Mine equipment
Property, Plant and Equipment [Line Items]
Depreciation Life or Method	7 years
Maximum | Vehicles
Property, Plant and Equipment [Line Items]
Depreciation Life or Method	5 years