Note 6 - Business Segments (Details) - Information about Reportable Segments - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Net sales to unaffiliated customers:
Net sales to unaffiliated customers	$ 104,941	$ 135,507	$ 328,230	$ 378,796
Income (loss) from operations:
Income (loss) from operations	(21,197)	6,271	(33,565)	19,215
Identifiable assets:
Identifiable assets	2,285,213		2,285,213		$ 2,262,064
Greens Creek [Member]
Net sales to unaffiliated customers:
Net sales to unaffiliated customers	54,351	67,763	175,749	186,808
Income (loss) from operations:
Income (loss) from operations	21	8,874	24,664	28,724
Identifiable assets:
Identifiable assets	702,244		702,244		704,121
Lucky Friday [Member]
Net sales to unaffiliated customers:
Net sales to unaffiliated customers	13,916	27,883	48,376	71,740
Income (loss) from operations:
Income (loss) from operations	(3,894)	9,007	(933)	20,105
Identifiable assets:
Identifiable assets	389,700		389,700		356,482
Casa Berardi [Member]
Net sales to unaffiliated customers:
Net sales to unaffiliated customers	36,674	39,861	104,105	120,248
Income (loss) from operations:
Income (loss) from operations	(2,603)	395	(6,567)	4,940
Identifiable assets:
Identifiable assets	776,442		776,442		800,961
San Sebastian [Member]
Income (loss) from operations:
Income (loss) from operations	(2,420)	(1,614)	(7,269)	(3,511)
Identifiable assets:
Identifiable assets	2,612		2,612		1,529
Other Segments [Member]
Income (loss) from operations:
Income (loss) from operations	(12,301)	$ (10,391)	(43,460)	$ (31,043)
Identifiable assets:
Identifiable assets	$ 414,215		$ 414,215		$ 398,971