Contingencies - Schedule of Contingencies Reserve Balance (Paranthetical) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023		Dec. 31, 2022		Dec. 31, 2024		Dec. 31, 2021
EPA Notice Letter [Member]
Loss Contingencies [Line Items]
Payment made to settle past cost claims	$ 1,900
New Idria Mercury Mine [Member]
Loss Contingencies [Line Items]
Amount of insurance refunds			$ 800
Accrual for Environmental Loss Contingencies	$ 13,182	[1]	$ 11,855	[1]	$ 12,425	[1]	$ 8,213
Estimated Insurance Recoveries					8,400
New Idria Mercury Mine [Member] | Other Current Liabilities [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies					$ 6,500
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration]					Other Accrued Liabilities, Current
New Idria Mercury Mine [Member] | Other Noncurrent Liabilities [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies					$ 5,900
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration]					Other Liabilities, Noncurrent
New Idria Mercury Mine [Member] | Accounts Receivable [Member]
Loss Contingencies [Line Items]
Estimated Insurance Recoveries					$ 3,900
New Idria Mercury Mine [Member] | Other Noncurrent Assets [Member]
Loss Contingencies [Line Items]
Estimated Insurance Recoveries					$ 4,500

[1] (2) As of December 31, 2024, Buckhorn has a total ending reserve balance of $12.4 million related to the New Idria Mine, of which $6.5 million is classified in Other current liabilities and $5.9 million in Other liabilities (long-term).