Note 2 - Business Segments and Sales of Products (Details Textual) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) Segment	Sep. 30, 2023 USD ($)
Segment Reporting, Revenue Reconciling Item [Line Items]
Derivative, Gain (Loss) on Derivative, Net, Total	$ 600	$ 4,000	$ 8,800	$ 13,100
Number of Reportable Segments | Segment			4
Writedown Of Plant And Equipment	14,464	$ 0	$ 14,464	$ 0
Property Plant And Mine Development (Member)
Segment Reporting, Revenue Reconciling Item [Line Items]
Writedown Of Plant And Equipment	14,500		14,500
Lucky Friday [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Business interruption insurance proceeds received	14,800		50,000
Writedown Of Plant And Equipment			13,900
Keno Hill [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 1,600		$ 3,000