Note 11 - Business Segments and Significant Customers (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Noncapital Costs	$ 25,300,000
Depreciation, Depletion and Amortization	50,113,000	47,348,000	60,235,000
Derivative, Loss on Derivative	1,300,000		3,000,000
Derivative, Gain on Derivative	10,500,000	7,100,000
Lucky Friday [Member]
Noncapital Costs	500,000
Depreciation, Depletion and Amortization	$ 6,300,000