Note 1 - Nature of the Business (Details) (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Disclosure Text Block [Abstract]      
Net Income (Loss) Attributable to Parent $ (30,712,000) $ (11,149,000) $ (21,194,000)
Net Cash Provided by (Used in) Operating Activities, Continuing Operations (26,230,000) (13,206,000) (18,836,000)
Cash, Cash Equivalents, and Short-term Investments $ 22,700,000 $ 48,100,000