Note 6 - Share Capital (Details) - Shares Underlying Outstanding Warrants Classified as Liabilities and Equity
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Class of Warrant or Right [Line Items]      
Shares underlying warrants outstanding classified as 8,230,848 10,922,090 5,922,090
Warrants Outstanding Classified as Liabilities [Member]      
Class of Warrant or Right [Line Items]      
Shares underlying warrants outstanding classified as 3,182,147 5,873,389  
Warrants Classified as Equity [Member]      
Class of Warrant or Right [Line Items]      
Shares underlying warrants outstanding classified as 5,048,701 5,048,701