Note 15 - Acquisitions (Details) - Unaudited Pro Forma Financial Information - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revett Mining Company Inc [Member]
Note 15 - Acquisitions (Details) - Unaudited Pro Forma Financial Information [Line Items]
Sales of products	$ 445,703	$ 500,787	$ 382,662
Net loss	(89,118)	(44,099)	(36,705)
Loss applicable to common stockholders	$ (89,670)	$ (44,651)	$ (37,257)
Basic and diluted loss per common share (in Dollars per share)	$ (0.24)	$ (0.12)	$ (0.11)
Aurizon Mines Ltd [Member]
Note 15 - Acquisitions (Details) - Unaudited Pro Forma Financial Information [Line Items]
Sales of products			$ 458,755
Net loss			(9,539)
Loss applicable to common stockholders			$ (10,091)
Basic and diluted loss per common share (in Dollars per share)			$ (0.03)