v3.19.2
Note 5 - Collaboration Agreement (Details Textual) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Dec. 31, 2018
 [1]
Revenue Recognition Milestone Method Agreed, Additional Amount, Based On Efforts And Targets $ 194,500   $ 194,500    
Revenue from Contract with Customer, Including Assessed Tax 941 $ 818 1,206 $ 1,161  
Contract with Customer, Liability, Current 324   324   $ 315
Contract with Customer, Liability, Noncurrent 2,990   2,990   $ 3,148
Collaboration Agreement Revenue [Member]          
Revenue from Contract with Customer, Including Assessed Tax 886 $ 351 1,104 $ 625  
Contract with Customer, Liability, Current 300   300    
Contract with Customer, Liability, Noncurrent 3,000   3,000    
Based upon Successful Regulatory and Product Development Efforts [Member]          
Revenue Recognition Milestone Method Agreed, Additional Amount, Based On Efforts And Targets 28,500   28,500    
Based upon Net Sales Target Achievements [Member]          
Revenue Recognition Milestone Method Agreed, Additional Amount, Based On Efforts And Targets $ 166,000   $ 166,000    
[1] The condensed consolidated balance sheet as of December 31, 2018 has been derived from the audited financial statements as of that date included in the Company's Annual Report on Form 10-K for the year ended December 31, 2018.