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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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Note 7 - Business Segments and Sales of Products (Details Textual) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($) oz T	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) oz T	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Number of Reportable Segments			5
Derivative, Gain on Derivative	$ 5,000		$ 8,300
Derivative, Loss on Derivative		$ 600		$ 3,900
Accounts Receivable, Net, Current, Total	12,947		12,947		$ 14,805
Allowance for Doubtful Accounts Receivable, Ending Balance	0		0		$ 0
Employee Labor Strike Related Costs	6,519	$ 4,780	18,337	14,385
Lucky Friday [Member]
Long-Lived Assets	$ 428,800		$ 428,800
Estimated Mine Life			22 years
Lucky Friday [Member] \| Suspension Costs [Member]
Employee Labor Strike Related Costs			$ 13,500	11,500
Lucky Friday [Member] \| Non-cash Depreciation Expense [Member]
Employee Labor Strike Related Costs			$ 3,700	$ 2,900
Silver [Member]
Metals Contained in Concentrates \| oz	1,200,000		1,200,000
Gold [Member]
Metals Contained in Concentrates \| oz	5,734		5,734
Zinc [Member]
Metals Contained in Concentrates \| T	7,277		7,277
Lead [Member]
Metals Contained in Concentrates \| T	2,447		2,447