Contingencies - Additional Information (Details) - USD ($)				3 Months Ended			9 Months Ended		12 Months Ended	144 Months Ended
		Feb. 14, 2023	Dec. 11, 2018	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2018	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2016	Sep. 30, 2023	Dec. 31, 2022
Loss Contingencies [Line Items]
Other current liabilities				$ 29,138,000			$ 29,138,000			$ 29,138,000	$ 26,380,000
Other liabilities				10,284,000			10,284,000			10,284,000	$ 15,270,000
New Idria Mercury Mine [Member]
Loss Contingencies [Line Items]
Financial assurance required to be provided to EPA to secure performance						$ 2,000,000
Loss contingencies, payments	[1],[2]			1,182,000	$ 123,000		4,455,000	$ 483,000
New Almaden Mine (Formerly Referred to as Guadalupe River Watershed) [Member] | Natural Resource Damage Claim [Member]
Loss Contingencies [Line Items]
Loss contingencies, payments				100,000			100,000
Total reserve				4,400,000			4,400,000			4,400,000
Other current liabilities				300,000			300,000			300,000
Other liabilities				4,100,000			4,100,000			4,100,000
Expense recognized				0	0		0	0
Revised estimated project cost							9,000,000
New Almaden Mine (Formerly Referred to as Guadalupe River Watershed) [Member] | Natural Resource Damage Claim [Member] | Minimum [Member]
Loss Contingencies [Line Items]
Original estimated project costs									$ 3,300,000
New Almaden Mine (Formerly Referred to as Guadalupe River Watershed) [Member] | Natural Resource Damage Claim [Member] | Maximum [Member]
Loss Contingencies [Line Items]
Original estimated project costs									$ 4,400,000
Patent Infringement [Member]
Loss Contingencies [Line Items]
Defense costs incurred			$ 13,300,000	100,000	$ 600,000		$ 3,600,000	$ 2,500,000
Payment From The Insurer				$ 500,000
Scepter Company [Member] | Ms.McCartney [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Sought, Value		$ 30,000
Pending Litigation [Member] | New Idria Mercury Mine [Member] | EPA Notice Letter [Member]
Loss Contingencies [Line Items]
Loss contingencies, payments										10,100,000
Insurance recoveries										3,400,000
Loss contingency, Loss in period										$ 19,300,000

[1] (1) Payments made in 2022 were offset by insurance refunds of $0.3 million and $0.4 million in the three and nine months ended September 30, 2022, 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.

[2] (4) 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.