v3.25.1
Note 14 - Stockholders' Equity (Details Textual) - USD ($)
$ / shares in Units, $ in Millions
 12 Months Ended
Jun. 14, 2024
Jun. 08, 2023
Aug. 11, 2022
Mar. 07, 2022
Jun. 30, 2024
Jun. 30, 2023
Dec. 31, 2022
Sep. 28, 2021
Jun. 04, 2021
Jun. 17, 2020
Common Stock, Shares Authorized (in shares)         200,000,000 200,000,000        
Common Stock, Par or Stated Value Per Share (in dollars per share)         $ 0.0001 $ 0.0001        
Preferred Stock, Shares Authorized (in shares)         50,000,000 50,000,000        
Preferred Stock, Par or Stated Value Per Share (in dollars per share)         $ 0.0001 $ 0.0001        
Common Stock, Shares, Issued (in shares)         5,972,638 5,517,174        
Common Stock, Shares, Outstanding (in shares)         5,972,638 5,517,174        
Preferred Stock, Shares Issued (in shares)         0 0        
Preferred Stock, Shares Outstanding (in shares)         0 0        
Proceeds from Warrant Exercises         $ 3.5          
Class of Warrant or Right, Issued During Period (in shares) [1]         1,806,434          
March 2022 Prefunded Warrants [Member]                    
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)       151,500            
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)       $ 0.002            
March 2022 Common Warrants [Member]                    
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)       333,300            
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)       $ 26            
March 2022 Common and Prefunded Warrants [Member]                    
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)       1.1            
Class of Warrant or Right, Exercisable Period (Month)       6 months            
Warrants and Rights Outstanding, Term (Year)       5 years            
Warrants and Rights Outstanding       $ 2.8            
August 2022 Prefunded Warrants [Member]                    
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)     87,500              
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)     $ 0.02              
August 2022 Common Warrants [Member]                    
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)     1,265,547              
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)     1              
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)     $ 8.6     $ 2.32 $ 3.3      
Warrants and Rights Outstanding, Term (Year)     5 years              
August 2022 Common and Prefunded Warrants [Member]                    
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)     1              
Warrants and Rights Outstanding, Term (Year)     5 years              
Warrants and Rights Outstanding     $ 6.0              
Equity Issuance, Price Per Share (in dollars per share)     $ 8.58              
Pre-Funded Warrants [Member]                    
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)   430,217                
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)   1                
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)   $ 0.0001 $ 0.02              
Tranche A Common Warrants [Member]                    
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)   2,173,912                
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)   $ 3.18                
Warrants and Rights Outstanding, Term (Year)   5 years                
Class of Warrant or Right, Expiration, Period After Threshold is Met (Day)   30 days                
Class of Warrant or Right, Expiration, Threshold Percentage of Exercise Price   200.00%                
Class of Warrant or Right, Expiration, Threshold Consecutive Trading Days (Day)   40 days                
Tranche B Common Warrants [Member]                    
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)   2,173,912                
Proceeds from Warrant Exercises $ 3.5                  
Stock Issued During Period, Shares, Warrants Exercised (in shares) 367,478                  
Common Warrants [Member]                    
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)   $ 1.59                
Common Warrants Exchanged for PreFunded Warrants [Member]                    
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)   $ 1.5899                
Securities Purchase Agreement Warrants [Member]                    
Payments of Stock Issuance Costs   $ 0.6                
Warrants and Rights Outstanding   $ 5.0                
Tranche B Pre-Funded Warrants [Member]                    
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) $ 0.0001                  
Warrants and Rights Outstanding $ 5.1                  
Class of Warrant or Right, Issued During Period (in shares) 1,806,434       1,806,434          
The 2020 Shelf [Member]                    
Sale of Stock, Maximum Amount of Equity Issuable                   $ 100.0
At-the-market Offering [Member]                    
Sale of Stock, Maximum Amount of Equity Issuable                 $ 30.0  
Stock Issued During Period, Shares, New Issues (in shares)           699,929        
Proceeds from Issuance of Common Stock           $ 2.9        
The 2021 Shelf [Member]                    
Sale of Stock, Maximum Amount of Equity Issuable               $ 100.0    
Sale of Stock, Available Amount of Equity Issuable         $ 82.4          
The 2024 Shelf [Member]                    
Sale of Stock, Maximum Amount of Equity Issuable         $ 100.0          
The March 2022 Offering [Member]                    
Stock Issued During Period, Shares, New Issues (in shares)       151,500            
Proceeds from Issuance or Sale of Equity       $ 7.6            
Payments of Stock Issuance Costs       $ 0.8            
The August 2022 Offering [Member]                    
Stock Issued During Period, Shares, New Issues (in shares)     1,075,290              
Proceeds from Issuance or Sale of Equity     $ 10.0              
Payments of Stock Issuance Costs     $ 0.9              
Equity Issuance, Price Per Share (in dollars per share)     $ 8.6              
Securities Purchase Agreement [Member]                    
Stock Issued During Period, Shares, New Issues (in shares)   1,743,695                
Proceeds from Issuance or Sale of Equity   $ 4.0                
Proceeds from Issuance or Sale of Equity, Net   $ 3.4                
Restricted Stock [Member]                    
Common Stock, Shares, Outstanding (in shares)         25,360          
[1] The warrants issued during fiscal 2024 were a result of 1,806,434 Tranche B Warrants being exercise to 1,806,434 Tranche B Pre-Funded Warrants.