Contingencies - Schedule of Contingencies Reserve Balance (Details) - New Idria Mercury Mine [Member] - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023		Dec. 31, 2022		Dec. 31, 2021
Loss Contingencies [Line Items]
Beginning reserve balance		$ 11,855	[1]	$ 8,213	[1]	$ 7,186
Changes in estimated environmental liability		6,500		4,400		700
Payments made	[2],[3]	(5,173)		(758)		327
Ending reserve balance	[1]	13,182		11,855		8,213
Beginning receivable balance		6,000	[4]	0	[4]	0
Changes in estimated insurance recovery		3,300		6,000		0
Insurance recovery reimbursements		(2,055)		0		0
Ending receivable balance	[4]	$ 7,245		$ 6,000		$ 0

[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).

[2] (4) Payments made for the year ended December 31, 2023 include a $1.9 million payment related to a settlement agreement with the EPA to resolve the past costs claim, which Buckhorn paid in the first quarter of 2023.

[3] (1) Payments made in the years ended December 31, 2022 and December 31, 2021 were offset by insurance refunds of $0.8 million and $0.7 million, respectively. In the fourth quarter of 2022, Buckhorn reached an agreement with respect to certain insurance coverage related to defense costs for which recovery of accrued costs are recorded as a receivable to the extent such recovery is determined to be probable under this agreement.

[4] (3) As of December 31, 2023, Buckhorn has a total receivable balance related to the probable insurance recovery of $7.2 million, of which $3.6 million is classified in Other accounts receivable and $3.6 million is classified in Other (long-term).