Quarterly report pursuant to Section 13 or 15(d)

Note 9 - Stockholders' Equity (Details Textual)

v3.23.2
Note 9 - Stockholders' Equity (Details Textual) - USD ($)
$ / shares in Units, $ in Millions
 1 Months Ended 6 Months Ended
Jun. 21, 2023
Jun. 22, 2022
Jun. 25, 2021
Nov. 30, 2022
Aug. 31, 2021
Jun. 30, 2023
Jun. 30, 2022
Dec. 31, 2022
Dec. 31, 2020
Common Stock, Shares Authorized (in shares)           300,000,000   300,000,000  
Common Stock, Shares, Issued (in shares)           98,851,927   74,519,103  
Common Stock, Par or Stated Value Per Share (in dollars per share)           $ 0.001   $ 0.001  
Preferred Stock, Shares Authorized (in shares)           10,000,000   10,000,000  
Preferred Stock, Shares Issued (in shares)           15,617   15,617  
Preferred Stock, Par or Stated Value Per Share (in dollars per share)           $ 0.001   $ 0.001  
Preferred Stock, Shares Outstanding, Ending Balance (in shares)           15,617   15,617  
Common Stock, Shares, Outstanding (in shares)           98,851,927   74,519,103  
Jefferies L L C [Member] | At the Market Offering [Member]                  
Sale of Stock, Authorized Amount       $ 75.0 $ 50.0        
Stock Issued During Period, Shares, New Issues (in shares)           24,300,000 1,900,000    
Stock Issued During Period, Value, Issued for Services           $ 20.3 $ 6.9    
Shares Issued, Price Per Share (in dollars per share)           $ 0.84 $ 3.57    
Employee Director And Consultant Equity Incentive Plan2020 [Member]                  
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares)                 3,500,000
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares)                 1,579,678
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Additional Shares Authorized (in shares) 6,000,000 3,000,000 2,250,000            
The 2023 Employee Stock Purchase Plan [Member]                  
Common Stock, Capital Shares Reserved for Future Issuance (in shares)           750,000      
Series A Preferred Stock [Member]                  
Preferred Stock, Shares Issued (in shares)           85   85  
Preferred Stock, Shares Outstanding, Ending Balance (in shares)           85   85  
Series B Preferred Stock [Member]                  
Preferred Stock, Shares Issued (in shares)           4,026   4,026  
Preferred Stock, Shares Outstanding, Ending Balance (in shares)           4,026   4,026  
Series C Preferred Stock [Member]                  
Preferred Stock, Shares Issued (in shares)           3,506   3,506  
Preferred Stock, Shares Outstanding, Ending Balance (in shares)           3,506   3,506  
Series D Preferred Stock [Member]                  
Preferred Stock, Shares Issued (in shares)           3,000   3,000  
Preferred Stock, Shares Outstanding, Ending Balance (in shares)           3,000   3,000  
Series E Preferred Stock [Member]                  
Preferred Stock, Shares Issued (in shares)           5,000   5,000  
Preferred Stock, Shares Outstanding, Ending Balance (in shares)           5,000   5,000