v3.26.1
Contingencies - Schedule of Contingencies Reserve Balance (Parenthetical) (Details) - New Idria Mercury Mine [Member] - USD ($)
$ in Thousands
Jun. 30, 2026
Mar. 31, 2026
Dec. 31, 2025
Jun. 30, 2025
 [1]
Mar. 31, 2025
Dec. 31, 2024
Loss Contingencies [Line Items]            
Accrual for Environmental Loss Contingencies $ 11,213 [1] $ 12,080 $ 12,504 $ 11,241 $ 11,719 $ 12,425
Estimated Insurance Recoveries 7,900          
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          
Other Noncurrent Liabilities [Member]            
Loss Contingencies [Line Items]            
Accrual for Environmental Loss Contingencies $ 2,900          
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration] Other Liabilities, Noncurrent          
Accounts Receivable [Member]            
Loss Contingencies [Line Items]            
Estimated Insurance Recoveries $ 4,500          
Other Noncurrent Assets [Member]            
Loss Contingencies [Line Items]            
Estimated Insurance Recoveries $ 3,400          
[1]

(1) As of June 30, 2026, Buckhorn has a total ending reserve balance of $11.2 million related to the New Idria Mine, of which $7.9 million is classified in Other current liabilities, $2.9 million in Other liabilities (long-term) and $0.4 million in Accounts payable.