Note 6 - Out-license Agreements (Details Textual)
$ in Thousands, € in Millions
1 Months Ended 3 Months Ended 12 Months Ended
Jul. 14, 2021
EUR (€)
Jul. 31, 2021
Sep. 30, 2021
USD ($)
Sep. 30, 2021
EUR (€)
Dec. 31, 2021
USD ($)
Dec. 31, 2021
EUR (€)
Dec. 31, 2020
USD ($)
Jul. 17, 2015
USD ($)
Revenue from Contract with Customer, Including Assessed Tax         $ 2,818   $ 5,416  
Amended License Agreement [Member]                
Revenue Recognition Milestone Method Agreed, Additional Amount, Based On Efforts And Targets               $ 194,500
Amended License Agreement [Member] | Based upon Successful Regulatory and Product Development Efforts [Member]                
Revenue Recognition Milestone Method Agreed, Additional Amount, Based On Efforts And Targets               28,500
Amended License Agreement [Member] | Based upon Net Sales Target Achievements [Member]                
Revenue Recognition Milestone Method Agreed, Additional Amount, Based On Efforts And Targets               $ 166,000
Aguettant [Member] | DZUVEO [Member]                
License Agreement, Renewal Term (Year) 5 years 5 years            
License Agreement, Upfront and Maximum Milestone Payments to be Received | € € 47.0              
Proceeds form Up-front and Sales-based Milestone License Payments     $ 2,900 € 2.5 2,900 € 2.5    
Revenue from Contract with Customer, Including Assessed Tax     $ 1,700   $ 1,700      
Aguettant [Member] | DZUVEO [Member] | Minimum [Member]                
License Agreement, Percent of Revenue Share Payments to be Received 35.00%              
Aguettant [Member] | DZUVEO [Member] | Maximum [Member]                
License Agreement, Percent of Revenue Share Payments to be Received 45.00%