Note 6 - Business Segments and Sales of Products - Information About Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Net sales	$ 139,709	$ 142,544
Income (loss) from operations	11,949	15,871
Greens Creek [Member]
Net sales	65,850	58,850
Income (loss) from operations	23,152	14,114
Lucky Friday [Member]
Net sales	4,977	20,010
Income (loss) from operations	(4,146)	3,880
Casa Berardi [Member]
Net sales	55,548	41,712
Income (loss) from operations	3,250	(2,245)
San Sebastian [Member]
Net sales	13,334	21,972
Income (loss) from operations	5,017	13,454
Other Segments [Member]
Income (loss) from operations	$ (15,324)	$ (13,332)

Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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