Note 8 - Shareholders' Equity (Details)			3 Months Ended		6 Months Ended		12 Months Ended
	Aug. 06, 2015 USD ($) $ / shares	Mar. 05, 2015 shares	Jun. 30, 2015 $ / shares $ / oz shares	Jun. 30, 2014 $ / shares shares	Jun. 30, 2015 USD ($) $ / shares $ / oz shares	Jun. 30, 2014 USD ($) $ / shares	Dec. 31, 2014 USD ($)	Jun. 15, 2015 CAD / shares	May. 08, 2012 shares
Note 8 - Shareholders' Equity (Details) [Line Items]
Common Stock, Dividends, Per Share, Declared (in Dollars per share) | $ / shares			$ 0.0025	$ 0.0025	$ 0.0050	$ 0.0050
undefined (in Dollars per Ounce) | $ / oz					16.32
Average Realized Silver Price, Minimum Dividend Threshold (in Dollars per Ounce) | $ / oz			30		30
Share Price (in Dollars per share) | CAD / shares								CAD 3.06
Non-employee Directors [Member]
Note 8 - Shareholders' Equity (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period			48,246	150,378
Employees and Non-employee Directors [Member]
Note 8 - Shareholders' Equity (Details) [Line Items]
Allocated Share-based Compensation Expense (in Dollars) | $					$ 2,300,000	$ 2,600,000
Common Stock Repurchase Program [Member]
Note 8 - Shareholders' Equity (Details) [Line Items]
Treasury Stock Acquired, Average Cost Per Share (in Dollars per share) | $ / shares					$ 3.99
Stock Repurchase Program, Number of Shares Authorized to be Repurchased									20,000,000
Cumulative Stock Repurchased			934,100		934,100
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased			19,100,000		19,100,000
Satisfy Withholding Obligations [Member]
Note 8 - Shareholders' Equity (Details) [Line Items]
Shares Paid for Tax Withholding for Share Based Compensation					284,243
Payments Related to Tax Withholding for Share-based Compensation (in Dollars) | $					$ 941,000
Treasury Stock Acquired, Average Cost Per Share (in Dollars per share) | $ / shares					$ 3.31
Subsequent Event [Member]
Note 8 - Shareholders' Equity (Details) [Line Items]
Common Stock, Dividends, Per Share, Declared (in Dollars per share) | $ / shares	$ 0.0025
Dividends, Common Stock (in Dollars) | $	$ 900,000
Share Price (in Dollars per share) | $ / shares			$ 2.02		2.02
Stock Awards [Member]
Note 8 - Shareholders' Equity (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period		911,148
Allocated Share-based Compensation Expense (in Dollars) | $							$ 3,000,000
Minimum [Member]
Note 8 - Shareholders' Equity (Details) [Line Items]
Common Stock, Dividends, Per Share, Declared (in Dollars per share) | $ / shares					$ 0.01