Note 11 - Derivative Instruments (Details) (USD $)	3 Months Ended
Mar. 31, 2014
Unsettled Concentrate Sales Contracts [Member]
Note 11 - Derivative Instruments (Details) [Line Items]
Derivative Asset, Current	$ 900,000
Derivative Liability, Current	400,000
Derivative, Gain on Derivative	19,000
Forecasted Future Concentrate Contracts [Member] \| Losses Realized On Settled Contracts [Member]
Note 11 - Derivative Instruments (Details) [Line Items]
Derivative, Gain on Derivative	2,000,000
Forecasted Future Concentrate Contracts [Member]
Note 11 - Derivative Instruments (Details) [Line Items]
Derivative Asset, Current	5,000,000
Derivative Liability, Current	200,000
Derivative, Gain on Derivative	9,500,000
Derivative Asset, Noncurrent	$ 7,400,000

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References+ Details

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled after one year or the normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References+ Details

- Definition

Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References+ Details