v3.20.2
Note 7 - Liability Related to Sale of Future Royalties (Details Textual) - USD ($)
$ / shares in Units, $ in Millions
 3 Months Ended 6 Months Ended 9 Months Ended
Sep. 18, 2015
Sep. 30, 2020
Jun. 30, 2020
Sep. 30, 2019
Jun. 30, 2019
Jun. 30, 2020
Sep. 30, 2020
Sep. 30, 2019
Proceeds From Sale of Royalty and Milestone Rights $ 65.0              
Royalty Arrangment Maximum Payments $ 195.0              
Prospective Average Rate for Remaining Term of the Agreement         4.20%      
Contingent Gain (Loss) on Royalty Monetization Arrangement     $ 65.0          
Effective Interest Over Life of Liability Related to Sale of Future Royalties           0.00%    
Effective Annual Interest Rate   3.60%   4.20%     3.60% 0.50%
Net Income (Loss) from Change Estimate on Liability Related to Sale of Future Royalties       $ (2.7)       $ (5.4)
Net Income (Loss) Per Share, Change Estimate on Liability Related to Sale of Future Royalties (in dollars per share)       $ (0.03)       $ (0.07)
PDL [Member]                
Percentage of Royalties and Rights Under Agreement 75.00%              
PDL [Member] | First Four Commercial Milestones [Member]                
Percentage of Royalties and Rights Under Agreement 80.00%              
Commercial Milestones Value Maximum Amount Available $ 35.6              
AcelRX [Member] | First Four Commercial Milestones [Member]                
Commercial Milestones Value Maximum Amount Available $ 44.5