Assets Held for Sale and Discontinued Operations - Schedule of Carrying Amounts of Major Classes of Assets and Liabilities of Discontinued Operations (Details) - Held for sale - USD ($) $ in Thousands		Sep. 30, 2025	Dec. 31, 2024
Assets
Property, plant and equipment, net	[1]	$ 667	$ 667
Total assets held for sale		667	667
Liabilities
Deferred revenue	[2]	2,972	1,820
Other current liabilities	[3]	150	150
Total current liabilities held for sale		3,122	1,970
Asset retirement and reclamation liabilities	[4]	3,467	3,281
Total liabilities held for sale		$ 6,589	$ 5,251

[1] Property, plant and equipment, net at September 30, 2025 and December 31, 2024 consisted of the remaining Velardeña Properties assets.

[2] Deferred revenue at September 30, 2025 and December 31, 2024 represents cash received for the sale of the Velardeña oxide plant.

[3] Other current liabilities at September 30, 2025 and December 31, 2024 consisted of the current portion of ARO.

[4] Asset retirement and reclamation liabilities at September 30, 2025 and December 31, 2024 relate to the Rodeo Property and Velardeña Properties.