Property, Plant and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Property, Plant and Equipment, Net
Property, plant and equipment, gross	$ 1,017	$ 1,225
Less: Accumulated depreciation and amortization	(630)	(782)
Property, plant and equipment, net	387	443
Exploration properties
Property, Plant and Equipment, Net
Property, plant and equipment, gross	150	150
Royalty properties
Property, Plant and Equipment, Net
Property, plant and equipment, gross	200	200
Buildings
Property, Plant and Equipment, Net
Property, plant and equipment, gross		48
Mining equipment and machinery
Property, Plant and Equipment, Net
Property, plant and equipment, gross	250	408
Other furniture and equipment
Property, Plant and Equipment, Net
Property, plant and equipment, gross	$ 417	$ 419