Note 4 - Environmental and Reclamation Activities (Details) - Reconciliation of Asset Retirement Obligations - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014
Reconciliation of Asset Retirement Obligations [Abstract]
Balance January 1	$ 46,539	$ 43,244
Changes in obligations due to changes in reclamation plans	4,112	675
Addition due to development and production at our San Sebastian unit	1,189
Accretion expense	1,904	3,089
Payment of reclamation obligations	(511)	(469)
Balance at December 31	$ 53,233	$ 46,539

No definition available.

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- Definition

The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Asset Retirement Obligation
-URI http://asc.fasb.org/extlink&oid=6505190

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- Definition

Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6392676&loc=d3e7480-110848

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- Definition

Amount of cash paid during the period to settle an asset retirement obligation. Amounts paid to settle an asset retirement obligation are generally included in the operating section of the Statement of Cash Flows.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 17
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3367-108585

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Amount of asset retirement obligations incurred during the period.

+ References

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Amount of the Increase or Decrease in the amount of the asset retirement obligation during the current period for changes in the amount or timing of the estimated cash flows associated with the settlement of the obligation.

+ References

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