v3.26.1
Note 9 - Warrants (Details Textual)
$ / shares in Units, $ in Thousands
 1 Months Ended 12 Months Ended 36 Months Ended 41 Months Ended 50 Months Ended 79 Months Ended
Sep. 10, 2025
$ / shares
shares
Apr. 02, 2025
$ / shares
shares
Jan. 17, 2024
USD ($)
$ / shares
shares
Dec. 29, 2022
$ / shares
shares
Nov. 15, 2021
USD ($)
$ / shares
shares
Nov. 30, 2025
shares
Oct. 31, 2025
$ / shares
shares
Sep. 30, 2025
$ / shares
shares
Dec. 31, 2025
USD ($)
$ / shares
shares
Dec. 31, 2024
USD ($)
$ / shares
shares
Dec. 31, 2025
USD ($)
$ / shares
shares
Dec. 31, 2025
USD ($)
$ / shares
shares
Dec. 31, 2025
USD ($)
$ / shares
shares
Dec. 31, 2025
USD ($)
$ / shares
shares
Jan. 22, 2024
shares
Dec. 31, 2023
$ / shares
shares
Jul. 31, 2023
shares
Jul. 20, 2023
USD ($)
$ / shares
shares
Aug. 03, 2022
$ / shares
May 30, 2019
$ / shares
shares
Class of Warrant or Right, Exercised (in shares)                 2,706,484                      
Class of Warrant or Right, Outstanding (in shares)                 39,319,028 29,474,257 39,319,028 39,319,028 39,319,028 39,319,028   21,682,049        
Equity Issuance Costs, Modification of Warrants | $                 $ 0 $ 251                    
Warrants and Rights Outstanding | $                 $ 2,376 $ 1,061 $ 2,376 $ 2,376 $ 2,376 $ 2,376            
The January 2024 Private Placement [Member]                                        
Proceeds from Issuance or Sale of Equity | $     $ 6,000                                  
2021 Registered Direct Offering [Member]                                        
Proceeds from Issuance or Sale of Equity | $         $ 14,000                              
September 2025 Prefunded Warrants [Member]                                        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) 5,845,455             5,845,455                        
Class of Warrant or Right, Issued During Period, Price Per Warrant (in dollars per share) | $ / shares $ 0.549             $ 0.549                        
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares $ 0.001     $ 0.001       $ 0.001                        
Class of Warrant or Right, Exercised (in shares)           1,000,000                            
Class of Warrant or Right, Outstanding (in shares)                 4,845,455   4,845,455 4,845,455 4,845,455 4,845,455            
April 2025 Prefunded Warrants [Member]                                        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)   4,999,316         1,706,484                          
Class of Warrant or Right, Issued During Period, Price Per Warrant (in dollars per share) | $ / shares   $ 0.585         $ 0.585                          
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares   $ 0.001         $ 0.001   $ 0.001   $ 0.001 $ 0.001 $ 0.001 $ 0.001            
Class of Warrant or Right, Exercised (in shares)             1,706,484                          
Class of Warrant or Right, Outstanding (in shares)                 4,999,316   4,999,316 4,999,316 4,999,316 4,999,316            
Prefunded 2024 Warrants [Member]                                        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)                             7,792,208          
Prefunded 2024 Warrants [Member] | Maximum [Member]                                        
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares     $ 1.11                                  
Prefunded 2024 Warrants [Member] | Minimum [Member]                                        
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares     $ 0.77                                  
Prefunded 2024 Warrants [Member] | Common Class A [Member]                                        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)                                 3,676,473      
Prefunded 2024 Warrants [Member] | Common Class B [Member]                                        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)                                 3,676,473      
Prefunded 2024 Warrants [Member] | The January 2024 Private Placement [Member]                                        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)     7,792,208                                  
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares     $ 0.001                                  
Modified January 2024 Warrants [Member]                                        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)     5,882,356                                  
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares     $ 0.77                                  
Equity Issuance Costs, Modification of Warrants | $     $ 300                                  
Modified January 2024 Warrants [Member] | Measurement Input, Share Price [Member]                                        
Warrants and Rights Outstanding, Measurement Input     0.769                                  
Modified January 2024 Warrants [Member] | Measurement Input, Expected Term [Member]                                        
Warrants and Rights Outstanding, Measurement Input     4.5                                  
Modified January 2024 Warrants [Member] | Measurement Input, Price Volatility [Member]                                        
Warrants and Rights Outstanding, Measurement Input     0.9691                                  
Modified January 2024 Warrants [Member] | Measurement Input, Risk Free Interest Rate [Member]                                        
Warrants and Rights Outstanding, Measurement Input     0.0402                                  
Modified January 2024 Warrants [Member] | Measurement Input, Expected Dividend Rate [Member]                                        
Warrants and Rights Outstanding, Measurement Input     0                                  
Modified January 2024 Warrants [Member] | Common Class A [Member]                                        
Class of Warrant or Right, Outstanding (in shares)     2,941,178                                  
Prefund Warrants [Member]                                        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)                                   2,012,356    
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares                                   $ 0.001    
Prefund Warrants [Member] | Maximum [Member]                                        
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares                                   $ 1.11    
Series A Common Stock Warrants [Member]                                        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)                                   7,352,947    
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares                                   $ 1.11    
Series B Common Stock Warrants [Member]                                        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)                                   7,352,947    
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares                                   $ 1.11    
Series A and B Common Stock Warrants [Member]                                        
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares                                   $ 1.7    
Warrants and Rights Outstanding, Term (Year)                                   5 years    
Class of Warrant or Right, Exercise, Percentage of Combined Offering Price                                   125.00%    
Warrants and Rights Outstanding | $                                   $ 300    
Series A and B Common Stock Warrants [Member] | Measurement Input, Share Price [Member]                                        
Warrants and Rights Outstanding, Measurement Input                                   1.07    
Series A and B Common Stock Warrants [Member] | Measurement Input, Expected Term [Member]                                        
Warrants and Rights Outstanding, Measurement Input                                   5    
Series A and B Common Stock Warrants [Member] | Measurement Input, Price Volatility [Member]                                        
Warrants and Rights Outstanding, Measurement Input                                   0.943    
Series A and B Common Stock Warrants [Member] | Measurement Input, Risk Free Interest Rate [Member]                                        
Warrants and Rights Outstanding, Measurement Input                                   0.0408    
Series A and B Common Stock Warrants [Member] | Measurement Input, Expected Dividend Rate [Member]                                        
Warrants and Rights Outstanding, Measurement Input                                   0    
Placement Agent Series A and B Common Stock Warrants [Member]                                        
Class of Warrant or Right, Exercised (in shares)                 0                      
The 2023 Prefunded Warrants [Member]                                        
Class of Warrant or Right, Exercised (in shares)                 595,883                      
Class of Warrant or Right, Outstanding (in shares)                 1,416,473   1,416,473 1,416,473 1,416,473 1,416,473            
The 2022 Prefunded Warrants [Member]                                        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)       2,632,898                                
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares       $ 0.0001                                
Class of Warrant or Right, Exercised (in shares)                 2,632,898                      
Class of Warrant or Right, Outstanding (in shares)                 0   0 0 0 0            
Common Warrants [Member]                                        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)       4,227,052         4,227,052   4,227,052 4,227,052 4,227,052 4,227,052            
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares       $ 2.07         $ 2.07 $ 2.07 $ 2.07 $ 2.07 $ 2.07 $ 2.07            
Class of Warrant or Right, Exercised (in shares)                     0                  
Warrants and Rights Outstanding, Term (Year)       6 years                                
Warrants and Rights Outstanding | $                 $ 2,400 $ 1,100 $ 2,400 $ 2,400 $ 2,400 $ 2,400            
Class of Warrant or Right, Exercisable Period       6 months                                
Common Warrants [Member] | Measurement Input, Share Price [Member]                                        
Warrants and Rights Outstanding, Measurement Input                 1.14 0.5241 1.14 1.14 1.14 1.14            
Common Warrants [Member] | Measurement Input, Expected Term [Member]                                        
Warrants and Rights Outstanding, Measurement Input                 3 4 3 3 3 3            
Common Warrants [Member] | Measurement Input, Price Volatility [Member]                                        
Warrants and Rights Outstanding, Measurement Input                 0.9623 1.0081 0.9623 0.9623 0.9623 0.9623            
Common Warrants [Member] | Measurement Input, Risk Free Interest Rate [Member]                                        
Warrants and Rights Outstanding, Measurement Input                 3.55 0.0433 3.55 3.55 3.55 3.55            
Common Warrants [Member] | Measurement Input, Expected Dividend Rate [Member]                                        
Warrants and Rights Outstanding, Measurement Input                 0 0 0 0 0 0            
Common Warrants [Member] | Minimum [Member]                                        
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares       $ 1                                
August 2022 LPC Warrant [Member]                                        
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares                                     $ 4.07  
Class of Warrant or Right, Exercised (in shares)                       0                
November 2021 Financing Warrants [Member]                                        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)         875,000                     125,000        
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares         $ 20                     $ 20        
Class of Warrant or Right, Exercised (in shares)                         0              
Warrants and Rights Outstanding, Term (Year)         5 years                              
Class of Warrant or Right, Exercisable Period         6 months                              
Stock Issued During Period, Shares, New Issues (in shares)         875,000                              
November 2021 Financing Warrants [Member] | Maximum [Member]                                        
Class of Warrant or Right, Required Percentage of Ownership to Become Exercisable         9.99%                              
Modified November 2021 Warrants [Member]                                        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)       750,000                                
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares       $ 2.07                                
Warrant In Connection with Oxford Finance Loan Agreement [Member]                                        
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)                                       8,833
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares                                       $ 56.6
Class of Warrant or Right, Exercised (in shares)                           0            
Warrants and Rights Outstanding, Term (Year)                                       10 years