v3.25.2
Note 10 - Stock-based Compensation Expense (Details Textual)
1 Months Ended 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2025
USD ($)
shares
Jun. 30, 2025
USD ($)
shares
Jun. 30, 2024
USD ($)
Jun. 30, 2025
USD ($)
shares
Jun. 30, 2024
USD ($)
shares
Dec. 31, 2024
shares
Jan. 01, 2025
shares
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period       10 years      
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross       375,400      
Executive Officer [Member]              
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross   0   0 39,721    
Share-Based Payment Arrangement, Option [Member]              
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount | $ $ 2,100,000 $ 2,100,000   $ 2,100,000      
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition       2 years 1 month 6 days      
Stock Option Vesting Terms As Improbable to Probable [Member] | Chief Financial Officer [Member]              
Share-Based Payment Arrangement, Plan Modification, Incremental Cost | $     $ 300,000   $ 300,000    
Share-Based Payment Arrangement, Accelerated Cost | $     $ 12,000   $ 12,000    
Stock Option Vesting Terms As Improbable to Probable [Member] | Chief Operating Officer [Member]              
Share-Based Payment Arrangement, Plan Modification, Incremental Cost | $   100,000   $ 100,000      
Share-Based Payment Arrangement, Accelerated Cost | $   $ 100,000   $ 100,000      
Equity Incentive Plan 2015 [Member]              
Percentage of Total Shares Eligible for Plan Reserve, On an Annual Basis       4.00%      
Share Based Compensation Arrangement By Share Based Payment Award, Number of Shares Available for Grant, Increase (in shares)             348,109
The 2018 Employee, Director and Consultant Equity Incentive Plan [Member]              
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant 0 0   0      
The 2018 Employee, Director and Consultant Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Option [Member]              
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period       10 years      
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period       4 years      
The 2018 Employee, Director and Consultant Equity Incentive Plan [Member] | Share-Based Payment Arrangement, Option [Member] | Share-Based Payment Arrangement, Tranche One [Member]              
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period       1 year      
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage       25.00%      
Inducement Options [Member]              
Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period 10 years         10 years  
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period 36 months         36 months  
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross 54,000         71,712  
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Employees           5  
The 2025 Equity Plan [Member]              
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant 751,400 751,400   751,400