Contingencies - Schedule of Contingencies Reserve Balance (Paranthetical) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023		Dec. 31, 2022		Dec. 31, 2021		Dec. 31, 2020
EPA Notice Letter [Member]
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies revision in estimates	$ 1,900
New Idria Mercury Mine [Member]
Loss Contingencies [Line Items]
Amount of insurance refunds			$ 800		$ 700
Accrual for Environmental Loss Contingencies	13,182	[1]	$ 11,855	[1]	$ 8,213	[1]	$ 7,186
Expected insurance recoveries	7,200
New Idria Mercury Mine [Member] | Other Current Liabilities [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies	$ 7,900
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration]	Other Accrued Liabilities, Current
New Idria Mercury Mine [Member] | Other Liabilities [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies	$ 5,300
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration]	Other Liabilities, Noncurrent
New Idria Mercury Mine [Member] | Other Accounts Receivable [Member]
Loss Contingencies [Line Items]
Expected insurance recoveries	$ 3,600
New Idria Mercury Mine [Member] | Other long-term Member
Loss Contingencies [Line Items]
Expected insurance recoveries	$ 3,600

[1] (2) As of December 31, 2023, Buckhorn has a total ending reserve balance of $13.2 million related to the New Idria Mine, of which $7.9 million is classified in Other current liabilities and $5.3 million in Other liabilities (long-term).