Assets Held for Sale and Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Carrying amounts of major classes of assets included as part of discontinued operations
Total current assets held for sale	$ 497		$ 830
Held for sale
Major classes of line items constituting pretax profit of discontinued operations
Sale of metals	1,225
Cost of metals sold	(2,924)
Reclamation expense	(75)	$ (73)
Other operating income	241	10
Severance and termination benefits	(1,190)
Depreciation and amortization	(95)	(95)
Pretax gain on the disposal of discontinued operations	(2,818)	(405)
Income tax expense		(51)
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest, Total	(2,818)	(456)
Carrying amounts of major classes of assets included as part of discontinued operations
Inventories, net	497		830
Total current assets held for sale	497		830
Property, plant and equipment, net	2,915		3,032
Total assets of the disposal group classified as held for sale in the condensed consolidated balance sheets	3,412		3,862
Carrying amounts of major classes of liabilities included as part of discontinued operations
Asset retirement and reclamation liabilities	3,865		3,790
Total liabilities of the disposal group classified as held for sale in the condensed consolidated balance sheets	$ 3,865		$ 3,790
Velardea mining concessions | Held for sale
Major classes of line items constituting pretax profit of discontinued operations
Velardea care and maintenance costs		$ (247)