Contingencies - Schedule of Contingencies Reserve Balance (Details) - New Idria Mercury Mine [Member] - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Loss Contingencies [Line Items]
Beginning reserve balance		$ 12,492	$ 12,082	$ 13,182	$ 11,855
Changes in estimated environmental liability		200	300	1,000	3,800
Payments made	[1]	(908)	(1,182)	(2,398)	(4,455)
Ending reserve balance	[2]	11,784	11,200	11,784	11,200
Beginning receivable balance		7,114	6,162	7,245	6,000
Changes in estimated insurance recovery		700	400	1,700	1,600
Insurance recovery reimbursements		(621)	(394)	(1,752)	(1,432)
Ending receivable balance	[3]	$ 7,193	$ 6,168	$ 7,193	$ 6,168

[1] (3) Payments made for the nine months ended September 30, 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.

[2] (1) As of September 30, 2024, Buckhorn has a total ending reserve balance of $11.8 million related to the New Idria Mine, of which $7.1 million is classified in Other current liabilities and $4.7 million in Other liabilities (long-term).

[3] (2) As of September 30, 2024, Buckhorn has a total receivable balance related to the probable insurance recovery of $7.2 million, of which $3.0 million is classified in Other accounts receivable and $4.2 million is classified in Other (long-term).