Note 8 - Derivative Instruments - Summary of Forward Sales Contracts (Details) oz in Thousands, lb in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2024 lb oz $ / $ $ / oz	Dec. 31, 2023 lb oz $ / $ $ / oz
Silver 2024 Settlements For Provisional Sales Member
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass | oz	2,617
Underlying, Derivative Mass | $ / oz	24.81
Silver 2023 Settlements For Provisional Sales Member
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass | oz		735
Underlying, Derivative Mass | $ / oz		24.4
Gold 2024 Settlements For Provisional Sales Member
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass | oz	9,060
Underlying, Derivative Mass | $ / oz	2,165
Gold 2023 Settlements For Provisional Sales Member
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass | oz		3
Underlying, Derivative Mass | $ / oz		2,045
Zinc 2023 Settlements For Provisional Sales Member
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass		441
Underlying, Derivative Mass | $ / $		1.51
Lead 2024 Settlements For Provisional Sales Member
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass	12,015
Underlying, Derivative Mass | $ / $	0.98
Lead 2023 Settlements For Provisional Sales Member
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass		15,542
Underlying, Derivative Mass | $ / $		1
Lead 2024 Settlements for Forecasted Sales [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass	45,691	56,713
Underlying, Derivative Mass | $ / $	0.98	0.98
Zinc 2025 Settlements For Forecasted Sales [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass		0
Lead 2025 Settlements For Forecasted Sales [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass	43,541	49,273
Underlying, Derivative Mass | $ / $	0.98	0.98