Note 11 - Business Segments and Significant Customers (Details) - Sales from Continuing Operations to Significant Metals Customers as a Percentage of Total Sales (Customer Concentration Risk [Member], Sales Revenue, Goods, Net [Member])	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Teck Metals Ltd.[Member]
Revenue, Major Customer [Line Items]
Major customer	25.00%	10.70%	51.10%
Korea Zinc [Member]
Revenue, Major Customer [Line Items]
Major customer	22.50%	37.20%	18.40%
Trafigura AG [Member]
Revenue, Major Customer [Line Items]
Major customer	8.80%	22.40%	12.40%
MS Zinc [Member]
Revenue, Major Customer [Line Items]
Major customer	7.50%	12.30%	6.90%
CIBC [Member]
Revenue, Major Customer [Line Items]
Major customer	10.90%