Note 13 - Condensed Quarterly Financial Data (Unaudited) (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended 3 Months Ended 6 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2013
Jun. 30, 2013
Note 13 - Condensed Quarterly Financial Data (Unaudited) (Details) [Line Items]                        
Research and Development Expense $ 41,884 $ 33,221 $ 22,001                  
Fair Value Adjustment of Warrants (796) (2,327) (25,520)                  
Other Operating Income (Expense) [Member] | Warrant [Member]                        
Note 13 - Condensed Quarterly Financial Data (Unaudited) (Details) [Line Items]                        
Fair Value Adjustment of Warrants       300 1,300 1,700 2,500 1,200 200 1,600 300  
Upfront Payment [Member] | Array BioPharma Inc. [Member]                        
Note 13 - Condensed Quarterly Financial Data (Unaudited) (Details) [Line Items]                        
Research and Development Expense       20,000                
Fair Value Adjustment of Warrants                       $ 10,000