Note 9 - Stockholders' Equity (Details)		1 Months Ended	12 Months Ended
	Feb. 25, 2013 $ / shares	Mar. 31, 2013 USD ($)	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Dec. 31, 2013 USD ($) shares	Feb. 19, 2016 $ / shares	Jun. 15, 2015 CAD / shares	Jun. 02, 2013 $ / shares	Jun. 02, 2013 CAD / shares	May. 08, 2012 USD ($)	Jun. 30, 2010 shares
Note 9 - Stockholders' Equity (Details) [Line Items]
Common Stock, Shares Authorized			500,000,000	500,000,000
Common Stock, Par or Stated Value Per Share (in Dollars per share) | $ / shares			$ 0.25	$ 0.25
Common Stock, Shares, Issued			378,112,840	367,376,863
Common Stock, Dividends, Per Share, Declared (in Dollars per share) | $ / shares	$ 0.01
Average Realized Silver Price (in Dollars) | $				$ 30	$ 30
Dividends, Common Stock (in Dollars) | $		$ 3,600,000	$ (3,739,000)	$ (3,546,000)	$ (6,062,000)
Share Price (in Dollars per share) | (per share)							CAD 3.06	$ 3.83	CAD 3.97
Class of Warrant or Right, Outstanding			2,249,550		22,307,623
Class of Warrant or Right, Exercise Price of Warrants or Rights (in Dollars per share) | $ / shares			$ 6.17	$ 54,400,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights			0.1622
Preferred Stock, Shares Authorized			5,000,000	5,000,000
Preferred Stock, Par or Stated Value Per Share (in Dollars per share) | $ / shares			$ 0.25	$ 0.25
Preferred Stock, Shares Outstanding			157,816	157,816
Preferred Stock, Liquidation Preference, Value (in Dollars) | $			$ 7,891,000	$ 7,891,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized (in Dollars) | $			$ 3,400,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant			506,921
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number			0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value (in Dollars) | $				$ 259,342
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price (in Dollars per share) | $ / shares				$ 5.47
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period			0	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross			0	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number			3,375,798	2,235,575
Stock Repurchased During Period, Value (in Dollars) | $			$ (940,000)	$ (1,501,000)	$ (286,000)
Common Stock Repurchase Program [Member]
Note 9 - Stockholders' Equity (Details) [Line Items]
Stock Repurchase Program, Authorized Amount (in Dollars) | $										$ 20,000,000
Cumulative Stock Repurchased			934,100
Treasury Stock Acquired, Average Cost Per Share (in Dollars per share) | $ / shares			$ 3.99
Stock Repurchase Program, Remaining Authorized Repurchase Amount (in Dollars) | $			$ 19,100,000
Series B Preferred Stock [Member]
Note 9 - Stockholders' Equity (Details) [Line Items]
Preferred Stock, Shares Outstanding			157,816
Preferred Stock, Dividend Rate, Per-Dollar-Amount (in Dollars per share) | $ / shares			$ 3.50
Preferred Stock, Redemption Price Per Share (in Dollars per share) | $ / shares			50
Preferred Stock, Liquidation Preference Per Share (in Dollars per share) | $ / shares			$ 50
Preferred Stock, Liquidation Preference, Value (in Dollars) | $			$ 7,900,000
Preferred Stock, Voting Rights			one
Preferred Stock Conversion Price (in Dollars per share) | $ / shares			$ 15.55
Preferred Stock Conversion Rate			3.2154%
Satisfy Withholding Obligations [Member]
Note 9 - Stockholders' Equity (Details) [Line Items]
Treasury Stock Acquired, Average Cost Per Share (in Dollars per share) | $ / shares			$ 3.06
Stock Repurchased During Period, Shares			613,698
Stock Repurchased During Period, Value (in Dollars) | $			$ 1,900,000
Subsequent Event [Member] | Common Stock Repurchase Program [Member]
Note 9 - Stockholders' Equity (Details) [Line Items]
Share Price (in Dollars per share) | $ / shares						$ 2.36
Stock Compensation Plan [Member]
Note 9 - Stockholders' Equity (Details) [Line Items]
Allocated Share-based Compensation Expense (in Dollars) | $			$ 5,400,000	5,000,000	4,500,000
Restricted Stock Units Vesting in June 2016 [Member]
Note 9 - Stockholders' Equity (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number			763,543
Restricted Stock Units Vesting in July 2016 [Member]
Note 9 - Stockholders' Equity (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number			802,111
Restricted Stock Units Vesting in August 2016 [Member]
Note 9 - Stockholders' Equity (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number			26,000
Restricted Stock Units Vesting in June 2017 [Member]
Note 9 - Stockholders' Equity (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number			414,546
Restricted Stock Units Vesting in July 2017 [Member]
Note 9 - Stockholders' Equity (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number			724,249
Restricted Stock Units Vesting in July 2018 [Member]
Note 9 - Stockholders' Equity (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number			645,349
Restricted Stock Units (RSUs) [Member]
Note 9 - Stockholders' Equity (Details) [Line Items]
Allocated Share-based Compensation Expense (in Dollars) | $			$ 4,000,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options (in Dollars) | $			4,900,000
Restricted Stock Units (RSUs) [Member] | Expense Recognized Over Remaining Vesting Period [Member]
Note 9 - Stockholders' Equity (Details) [Line Items]
Allocated Share-based Compensation Expense (in Dollars) | $			$ 4,300,000
Two Thousand Ten Stock Incentive Plan [Member]
Note 9 - Stockholders' Equity (Details) [Line Items]
Allocated Share-based Compensation Expense (in Dollars) | $				$ 366,000	$ 276,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized											20,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant			11,975,936
Two Thousand Ten Stock Incentive Plan [Member] | Non-employee Directors [Member]
Note 9 - Stockholders' Equity (Details) [Line Items]
Allocated Share-based Compensation Expense (in Dollars) | $			$ 456,000
Stock Issued During Period, Shares, Share-based Compensation, Gross			186,888	110,910	94,200
Directors Stock Plan [Member]
Note 9 - Stockholders' Equity (Details) [Line Items]
Allocated Share-based Compensation Expense (in Dollars) | $			$ 150,000	$ 109,000	$ 111,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized			1,000,000
Share-based Compensation Arrangement by Share-based Payment Award Method of Measuring Cost of Award Participant Numerator (in Dollars) | $			$ 24,000
Stock Issued During Period, Shares, Share-based Compensation, Gross			48,244	39,468	28,050
Minimum [Member]
Note 9 - Stockholders' Equity (Details) [Line Items]
Common Stock, Dividends, Per Share, Declared (in Dollars per share) | $ / shares	$ 0.0025		$ 0.01
Average Realized Silver Price (in Dollars) | $			$ 30