Note 8 - Shareholders' Equity (Details) (USD $)	0 Months Ended	1 Months Ended		3 Months Ended		6 Months Ended	9 Months Ended			0 Months Ended					9 Months Ended	0 Months Ended		3 Months Ended
	Mar. 03, 2014	Dec. 31, 2013	Feb. 28, 2012	Sep. 30, 2014	Sep. 30, 2013	Jun. 30, 2014	Sep. 30, 2014	Sep. 30, 2013	May 08, 2012	Jun. 25, 2014 Restricted Stock Units (RSUs) [Member] Recognized Over the Next 12 Months [Member] Vesting in June 2015 [Member]	Jun. 25, 2014 Restricted Stock Units (RSUs) [Member] Recognized Over the Next 24 Months [Member] Vesting in June 2016 [Member]	Jun. 25, 2014 Restricted Stock Units (RSUs) [Member] Vesting: One Third in June 2015, One Third in June 2016, and One Third in June 2017 [Member]	Jun. 25, 2014 Restricted Stock Units (RSUs) [Member] Vesting: One Half in June 2015 and One Half in June 2016 [Member]	Jun. 25, 2014 Restricted Stock Units (RSUs) [Member] Vesting in June 2015 [Member]	Sep. 30, 2014 Restricted Stock Units (RSUs) [Member]	Nov. 04, 2014 Subsequent Event [Member]	Nov. 03, 2014 Subsequent Event [Member]	Sep. 30, 2014 Minimum [Member]
Note 8 - Shareholders' Equity (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures (in Shares)	1,345,072
Allocated Share-based Compensation Expense		$ 4,600,000					$ 3,800,000	$ 3,300,000		$ 3,100,000	$ 1,700,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period (in Shares)												1,251,213	107,576	87,872
Treasury Stock, Value, Acquired, Cost Method							2,300,000								695,961
Treasury Stock Acquired, Average Cost Per Share (in Dollars per share)							$ 3.27
Common Stock, Dividends, Per Share, Declared (in Dollars per share)			$ 0.01	$ 0.0025	$ 0.0025		$ 0.0075	$ 0.0075								$ 0.0025
Dividends, Common Stock																900,000
Average Realized Silver Price				$ 18.53														$ 30
Class of Warrant or Right, Outstanding (in Shares)		22,307,623
Class of Warrant or Right, Exercise Price of Warrants or Rights (in Dollars per share)		$ 54,400,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in Shares)									20,000,000
Treasury Stock, Shares, Acquired (in Shares)						533,800	934,100
Accelerated Share Repurchases, Final Price Paid Per Share (in Dollars per share)						$ 2.81	$ 3.99
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased (in Shares)						19,100,000
Share Price (in Dollars per share)																	$ 2.29