v3.25.2
Note 1 - Nature of the Business (Details Textual) - USD ($)
$ / shares in Units, $ in Thousands
1 Months Ended 3 Months Ended 6 Months Ended 12 Months Ended
Aug. 14, 2025
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Dec. 31, 2024
Dec. 30, 2020
Common Stock, Par or Stated Value Per Share (in dollars per share)   $ 0.0001   $ 0.0001   $ 0.0001 $ 0.0001
Operating Income (Loss)   $ (5,864) $ (7,391) $ (9,940) $ (16,623)    
Retained Earnings (Accumulated Deficit)   (290,293)   (290,293)   $ (282,123)  
Cash, Cash Equivalents, and Short-Term Investments   7,300   7,300   12,200  
Cash Provided by (Used in) Operating Activity, Including Discontinued Operation       (9,755) $ (13,438)    
Minimum Cash Balance For Loan Covenant           $ 2,000  
Subsequent Event [Member] | Senior Secured Convertible Promissory Notes [Member]              
Proceeds from Convertible Debt $ 1,500            
ATM Facility [Member]              
Proceeds from Issuance or Sale of Equity   $ 2,300   $ 5,100      
ATM Facility [Member] | Subsequent Event [Member]              
Proceeds from Issuance or Sale of Equity $ 1,900