Note 9 - Derivative Instruments - Summary of Forward Sales Contracts (Details) oz in Thousands, lb in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2026 USD ($) oz lb $ / £	Dec. 31, 2025 lb $ / £
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| oz	10,000
Assets Needed for Immediate Settlement, Aggregate Fair Value	$ 50
Silver 2026 Settlements For Provisional Sales [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| oz	400
Silver 2026 Settlements For Provisional Sales [Member] \| Maximum [Member]
Derivative [Line Items]
Assets Needed for Immediate Settlement, Aggregate Fair Value	$ 75.71
Silver 2026 Settlements For Provisional Sales [Member] \| Minimum [Member]
Derivative [Line Items]
Assets Needed for Immediate Settlement, Aggregate Fair Value	$ 48.67
Gold 2026 Settlements For Provisional Sales [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| oz	1
Gold 2026 Settlements For Provisional Sales [Member] \| Maximum [Member]
Derivative [Line Items]
Assets Needed for Immediate Settlement, Aggregate Fair Value	$ 5,425
Gold 2026 Settlements For Provisional Sales [Member] \| Minimum [Member]
Derivative [Line Items]
Assets Needed for Immediate Settlement, Aggregate Fair Value	$ 5,125
Zinc 2026 Settlements for Provisional Sales [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb	13,173	18,850
Underlying, Derivative Mass \| $ / £	1.33	1.37
Lead 2026 Settlements For Provisional Sales [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb	15,653	13,117
Underlying, Derivative Mass \| $ / £	1.04	1.05
Zinc 2026 Settlements For Forecasted Sales [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb	40,234	53,407
Underlying, Derivative Mass \| $ / £	1.32	1.33
Zinc 2027 Settlements For Forecasted Sales [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb	45,636	23,810
Underlying, Derivative Mass \| $ / £	1.4	1.36
Lead 2026 Settlements For Forecasted Sale [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb	24,912	42,108
Underlying, Derivative Mass \| $ / £	1	1.02
Lead 2027 Settlements For Forecasted Sales [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb	0	0
Underlying, Derivative Mass \| $ / £	0
Silver 2026 Settlements For Forecasted Sales [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| oz	350
Silver 2026 Settlements For Forecasted Sales [Member] \| Maximum [Member]
Derivative [Line Items]
Assets Needed for Immediate Settlement, Aggregate Fair Value	$ 58.25
Silver 2026 Settlements For Forecasted Sales [Member] \| Minimum [Member]
Derivative [Line Items]
Assets Needed for Immediate Settlement, Aggregate Fair Value	$ 35.33
Gold 2026 Settlements For Forecasted Sales [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| oz	0
Gold 2026 Settlements For Forecasted Sales [Member] \| Maximum [Member]
Derivative [Line Items]
Assets Needed for Immediate Settlement, Aggregate Fair Value	$ 0
Gold 2026 Settlements For Forecasted Sales [Member] \| Minimum [Member]
Derivative [Line Items]
Assets Needed for Immediate Settlement, Aggregate Fair Value	$ 0

The aggregate fair value of assets needed to immediately settle the derivative instruments with credit-risk-related contingent features if the credit-risk-related contingent features were triggered at the end of the reporting period.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4H
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-4H

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 25
-Paragraph 6A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480682/815-20-25-6A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480237/815-40-50-5

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