Note 11 - Derivative Instruments (Tables)

9 Months Ended

Sep. 30, 2013

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]

September 30, 2013	Ounces/pounds under contract (in 000's)								Average price per ounce/pound
	Silver (ounces)		Gold (ounces)		Zinc (pounds)		Lead (pounds)		Silver (ounces)		Gold (ounces)		Zinc (pounds)		Lead (pounds)
Contracts on provisional sales
2013 settlements		1,384		5		16,975		8,047	$	22.40	$	1,354	$	0.87	$	0.97
Contracts on forecasted sales
2013 settlements		—		—		3,527		4,079		—		—	$	0.95	$	1.07
2014 settlements		—		—		60,516		47,619		—		—	$	0.99	$	1.05
2015 settlements		—		—		42,769		39,628		—		—	$	0.96	$	1.07
2016 settlements		—		—		661		9,755		—		—	$	0.97	$	1.04

December 31, 2012	Ounces/pounds under contract (in 000's)								Average price per ounce/pound
	Silver (ounces)		Gold (ounces)		Zinc (pounds)		Lead (pounds)		Silver (ounces)		Gold (ounces)		Zinc (pounds)		Lead (pounds)
Contracts on provisional sales
2013 settlements		—		—		14,991		6,945		—		—	$	0.95	$	1.00
Contracts on forecasted sales
2013 settlements		—		—		35,935		32,794		—		—	$	0.96	$	1.11
2014 settlements		—		—		30,203		33,069		—		—	$	0.98	$	1.03
2015 settlements		—		—		3,307		23,534		—		—	$	1.01	$	1.06