v3.26.1
Note 10 - Equity Incentive Plans (Details Textual) - USD ($)
 3 Months Ended 12 Months Ended
Jun. 11, 2024
Mar. 31, 2026
Mar. 31, 2025
Dec. 31, 2025
Dec. 31, 2024
Feb. 27, 2024
Dec. 31, 2023
Aug. 04, 2022
Jun. 16, 2021
Jun. 08, 2020
Apr. 23, 2019
Common Stock, Capital Shares Reserved for Future Issuance (in shares)   42,413,698   43,850,083 45,575,342            
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number (in shares)   27,767,619   25,407,299 20,405,239   17,938,726        
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price (in dollars per share)   $ 1.62   $ 1.96 $ 2.49   $ 2.9        
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted-Average Remaining Contractual Term (Year)   7 years 4 months 24 days   7 years 3 months 10 days              
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value   $ 667,000   $ 4,000              
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Exercisable, Number (in shares)   13,614,279   14,808,497              
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price (in dollars per share)   $ 2.59   $ 2.84              
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term (Year)   6 years 14 days   6 years 1 month 28 days              
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value   $ 161,000   $ 4,000              
Proceeds from Stock Options Exercised   $ 0 $ 3,000 $ 3,000 $ 30,000            
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period (in shares)   (0) 3,625 3,625 38,030            
Share Price (in dollars per share)   $ 0.61 $ 0.85 $ 0.35              
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value     $ 0   $ 7,000            
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share)   $ 0.59 $ 0.46 $ 0.47 $ 1.01            
Share-Based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount   $ 12,100,000   $ 9,200,000              
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)   3 years   2 years 4 months 24 days              
Proceeds from Stock Plans       $ 0 $ 312,000            
Share-Based Payment Arrangement, Expense   $ 1,482,000 $ 2,459,000 $ 8,314,000 $ 11,501,000            
The 2019 Plan [Member]                      
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares) 43,900,000             28,900,000 16,900,000 8,000,000 1,600,000
Common Stock, Capital Shares Reserved for Future Issuance (in shares)   6,043,856   10,831,860 18,046,374            
The 2024 Inducement Award Plan [Member]                      
Common Stock, Capital Shares Reserved for Future Issuance (in shares)   76,250   43,250 1,603,750 3,000,000          
The 2022 ESPP [Member]                      
Common Stock, Capital Shares Reserved for Future Issuance (in shares) 3,600,000     1,823,454       1,800,000      
Common Stock, Capital Shares Reserved for Future Issuance, Increase (in shares) 1,800,000                    
Proceeds from Stock Plans       $ 200,000 $ 500,000            
Stock Issued During Period, Shares, Employee Stock Purchase Plans (in shares)       539,448 782,939            
Share-Based Payment Arrangement, Expense       $ 200,000 $ 200,000