Note 11 - Derivative Instruments (Details) - Summary Of Forward Sales Contracts (USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2013 lb	Dec. 31, 2012 lb
2013 Settlements [Member] | Silver [Member]
Note 11 - Derivative Instruments (Details) - Summary Of Forward Sales Contracts [Line Items]
Ounces Under Contract (in Pounds and Ounces)	1,384
Average Price Per Ounce	$ 22.40
Average Price Per Pound	22.40
2013 Settlements [Member] | Gold [Member]
Note 11 - Derivative Instruments (Details) - Summary Of Forward Sales Contracts [Line Items]
Ounces Under Contract (in Pounds and Ounces)	5
Average Price Per Ounce	1,354
Average Price Per Pound	1,354
2013 Settlements [Member] | Zinc [Member]
Note 11 - Derivative Instruments (Details) - Summary Of Forward Sales Contracts [Line Items]
Pounds Under Contract (in Pounds)	16,975	14,991
Average Price Per Ounce	0.87	0.95
Average Price Per Pound	0.87	0.95
Pounds Under Contract (in Pounds)	3,527	35,935
Average Price Per Pound	0.95	0.96
2013 Settlements [Member] | Lead [Member]
Note 11 - Derivative Instruments (Details) - Summary Of Forward Sales Contracts [Line Items]
Pounds Under Contract (in Pounds)	8,047	6,945
Average Price Per Ounce	0.97	1.00
Average Price Per Pound	0.97	1.00
Pounds Under Contract (in Pounds)	4,079	32,794
Average Price Per Pound	1.07	1.11
2014 Settlements [Member] | Zinc [Member]
Note 11 - Derivative Instruments (Details) - Summary Of Forward Sales Contracts [Line Items]
Pounds Under Contract (in Pounds)	60,516	30,203
Average Price Per Pound	0.99	0.98
2014 Settlements [Member] | Lead [Member]
Note 11 - Derivative Instruments (Details) - Summary Of Forward Sales Contracts [Line Items]
Pounds Under Contract (in Pounds)	47,619	33,069
Average Price Per Pound	1.05	1.03
2015 Settlements [Member] | Zinc [Member]
Note 11 - Derivative Instruments (Details) - Summary Of Forward Sales Contracts [Line Items]
Pounds Under Contract (in Pounds)	42,769	3,307
Average Price Per Pound	0.96	1.01
2015 Settlements [Member] | Lead [Member]
Note 11 - Derivative Instruments (Details) - Summary Of Forward Sales Contracts [Line Items]
Pounds Under Contract (in Pounds)	39,628	23,534
Average Price Per Pound	1.07	1.06
2016 Settlements [Member] | Zinc [Member]
Note 11 - Derivative Instruments (Details) - Summary Of Forward Sales Contracts [Line Items]
Pounds Under Contract (in Pounds)	661
Average Price Per Pound	0.97
2016 Settlements [Member] | Lead [Member]
Note 11 - Derivative Instruments (Details) - Summary Of Forward Sales Contracts [Line Items]
Pounds Under Contract (in Pounds)	9,755
Average Price Per Pound	$ 1.04