Note 8 - Derivative Instruments - Summary of Forward Sales Contracts (Details) oz in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2026 USD ($) lb oz $ / £	Dec. 31, 2025 lb $ / £
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| oz	6,767
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	475,000
Silver 2026 Settlements For Provisional Sales [Member] \| Maximum [Member]
Derivative [Line Items]
Assets Needed for Immediate Settlement, Aggregate Fair Value \| $	$ 82,350
Silver 2026 Settlements For Provisional Sales [Member] \| Minimum [Member]
Derivative [Line Items]
Assets Needed for Immediate Settlement, Aggregate Fair Value \| $	$ 72,600
Gold 2026 Settlements For Provisional Sales [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| oz	370
Zinc 2026 Settlements for Provisional Sales [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb	23,920	18,850
Underlying, Derivative Mass \| $ / £	1.37	1.37
Lead 2026 Settlements For Provisional Sales [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb	15,432	13,117
Underlying, Derivative Mass \| $ / £	1.02	1.05
Zinc 2026 Settlements For Forecasted Sales [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb	18,574	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	53,242	23,810
Underlying, Derivative Mass \| $ / £	1.41	1.36
Lead 2026 Settlements For Forecasted Sale [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb	8,818	42,108
Underlying, Derivative Mass \| $ / £	0.98	1.02
Lead 2027 Settlements For Forecasted Sales [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb	0	0
Underlying, Derivative Mass \| $ / £	0
Gold 2026 Settlements For Forecasted Sales [Member] \| Maximum [Member]
Derivative [Line Items]
Assets Needed for Immediate Settlement, Aggregate Fair Value \| $	$ 4,900,000
Gold 2026 Settlements For Forecasted Sales [Member] \| Minimum [Member]
Derivative [Line Items]
Assets Needed for Immediate Settlement, Aggregate Fair Value \| $	$ 4,600,000

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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