Note 3 - Fair Value Measurements (Details) - Change in Fair Value of the Warrant Liability (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Change in Fair Value of the Warrant Liability [Abstract]    
Balance $ 924 $ 3,251
Change in fair value of warrant liability included in    
Other expense (income) (796) (2,327)
Balance $ 128 $ 924