Note 15 - Acquisitions (Details) CAD / shares in Units, $ / shares in Units, $ in Thousands, CAD in Millions					1 Months Ended	12 Months Ended
	Jun. 15, 2015 USD ($) $ / shares shares	Aug. 23, 2013 USD ($) $ / shares	Jun. 02, 2013 USD ($) $ / shares shares	Jun. 02, 2013 CAD shares	Apr. 30, 2013 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Jun. 30, 2015 USD ($)	Jun. 15, 2015 CAD / shares	Jun. 02, 2013 CAD / shares shares
Note 15 - Acquisitions (Details) [Line Items]
Business Combination, Consideration Transferred			$ 714,500	CAD 740.8
Payments to Acquire Businesses, Gross			$ 496,200	CAD 514.5
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares (in Shares) | shares	6,252,646		56,997,790	56,997,790
Share Price | (per share)			$ 3.83							CAD 3.06	CAD 3.97
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment							$ 715,400
Insurance Policy									$ 16,800
Business Combination, Acquisition Related Costs						$ 2,162		$ 26,397
Business Acquisition Cost Sensitivity to Change in Share Price (in Dollars per share) | $ / shares			$ 3.00
Potential Business Acquitision Shares Issued (in Shares) | shares			0.3442								0.3442
Business Acquisition Shares Outstanding of Entity Acquired (in Shares) | shares			164,838,377								164,838,377
Business Acquisition Shares Issued and Outstanding of Acquired Entity (in Shares) | shares			165,585,509	165,585,509
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable			$ 218,300	CAD 226.3
Exchange Rate			0.9645	0.9645
Proceeds from Notes Payable					$ 490,000
Revett Mining Company Inc [Member]
Note 15 - Acquisitions (Details) [Line Items]
Ownership Percentage	100.00%
Number of Properties	2
Insurance Policy	$ 16,800
Impairment of Long-Lived Assets Held-for-use							54,700
In the Money Stock Options [Member]
Note 15 - Acquisitions (Details) [Line Items]
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares (in Shares) | shares			747,132	747,132
Plant and Equipment [Member]
Note 15 - Acquisitions (Details) [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment							127,800
Asset Retirement Obligation [Member]
Note 15 - Acquisitions (Details) [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment							11,100
Development and Other Mineral Interests [Member]
Note 15 - Acquisitions (Details) [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment							$ 576,500
Revett Mining Company Inc [Member]
Note 15 - Acquisitions (Details) [Line Items]
Business Combination, Consideration Transferred	20,082
Payments to Acquire Businesses, Gross	949
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned	$ 19,100
Business Acquistion, Number of Common Stock Shares Exchanged for Each Share of Acquiree Common Stock (in Shares) | shares	0.1622
Business Acquisition, Common Shares Outstanding of Acquiree (in Shares) | shares	38,548,989
Business Acquisition, Shares Owned By Subsidary Number of Shares Cancelled (in Shares) | shares	725,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	$ 17,609
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Reclamation Liability	17,513								17,500
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed Reclamation Insurance Asset	$ 16,800								$ 16,800
Business Combination, Acquisition Related Costs						2,400
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual						$ 1,700
Business Acquisition Per Share Consideration | $ / shares	$ 3.06
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable	$ 19,133
Revett Mining Company Inc [Member] | Plant and Equipment [Member]
Note 15 - Acquisitions (Details) [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	4,100
Revett Mining Company Inc [Member] | Land [Member]
Note 15 - Acquisitions (Details) [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	4,600
Revett Mining Company Inc [Member] | Mineral Interests [Member]
Note 15 - Acquisitions (Details) [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	$ 8,900
Aurizon Mines Ltd [Member]
Note 15 - Acquisitions (Details) [Line Items]
Business Combination, Consideration Transferred		$ 714,513
Payments to Acquire Businesses, Gross		496,211
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment		715,391
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Reclamation Liability		$ 11,113
Business Acquisition Per Share Consideration | (per share)		$ 3.83	$ 4.32								CAD 4.47
Business Acquisition, Share Price (in Dollars per share) | CAD / shares											4.75
Business Acquisition Per Share Issued (in Shares) | shares			0.9953	0.9953
Potential Business Acquisition Per Share Price (in Dollars per share) | CAD / shares											CAD 3.11
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable		$ 218,302