Contingencies - Schedule of Contingencies Reserve Balance (Details) - New Idria Mercury Mine [Member] - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Loss Contingencies [Line Items]
Beginning reserve balance		$ 12,315	$ 10,724	$ 13,182	$ 11,855
Changes in estimated environmental liability		800	1,900	800	3,500
Payments made	[1]	(623)	(542)	(1,490)	(3,273)
Ending reserve balance	[2]	12,492	12,082	12,492	12,082
Beginning receivable balance		7,020	6,224	7,245	6,000
Changes in estimated insurance recovery		700	100	1,000	1,200
Insurance recovery reimbursements		(606)	(162)	(1,131)	(1,038)
Ending receivable balance	[3]	$ 7,114	$ 6,162	$ 7,114	$ 6,162

[1] (3) Payments made for the six months ended June 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 June 30, 2024, Buckhorn has a total ending reserve balance of $12.5 million related to the New Idria Mine, of which $6.4 million is classified in Other current liabilities and $6.1 million in Other liabilities (long-term).

[3] (2) As of June 30, 2024, Buckhorn has a total receivable balance related to the probable insurance recovery of $7.1 million, of which $2.9 million is classified in Other accounts receivable and $4.2 million is classified in Other (long-term).