Note 6 - Business Segments - Information about Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Greens Creek [Member]
Net sales to unaffiliated customers	$ 85,804	$ 54,351	$ 199,260	$ 175,749
Income (loss) from operations	26,498	21	49,407	24,664
Lucky Friday [Member]
Net sales to unaffiliated customers	26,140	13,916	70,152	48,376
Income (loss) from operations	6,652	(3,894)	13,442	(933)
Casa Berardi [Member]
Net sales to unaffiliated customers	41,131	36,674	126,614	104,105
Income (loss) from operations	3,691	(2,603)	16,246	(6,567)
San Sebastian [Member]
Net sales to unaffiliated customers	26,318		85,686
Income (loss) from operations	18,415	(2,420)	58,911	(7,269)
Other Segments [Member]
Income (loss) from operations	(17,016)	(12,301)	(42,584)	(43,460)
Net sales to unaffiliated customers	179,393	104,941	481,712	328,230
Income (loss) from operations	$ 38,240	$ (21,197)	$ 95,422	$ (33,565)