Note 6 - Business Segments - Identifiable Assets by Reporting Segments (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Identifiable assets	$ 2,396,183	$ 2,371,677
Greens Creek [Member]
Identifiable assets	666,463	681,303
Lucky Friday [Member]
Identifiable assets	432,752	442,829
Casa Berardi [Member]
Identifiable assets	814,053	806,044
San Sebastian [Member]
Identifiable assets	55,395	33,608
Other Segments [Member]
Identifiable assets	$ 427,520	$ 407,893