Note 10 - Share-based Compensation (Details Textual) - USD ($) $ / shares in Units, $ in Thousands | 1 Months Ended | 3 Months Ended | 9 Months Ended | | |
Jun. 30, 2022 | Apr. 30, 2022 | Jan. 31, 2022 | Jun. 30, 2021 | Jun. 30, 2020 | May 31, 2019 | Sep. 30, 2022 | Sep. 30, 2021 | Sep. 30, 2022 | Sep. 30, 2021 | Dec. 31, 2021 | Mar. 31, 2017 |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number, Ending Balance | | | | | | | 5,636,313 | | 5,636,313 | | 3,935,883 | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross | | | | | | | | | 2,734,639 | | | |
Share-Based Payment Arrangement, Expense | | | | | | | $ 872 | $ 1,303 | $ 2,628 | $ 4,310 | | |
Employment Inducement Grant [Member] | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross | | 1,049,145 | | | | | | | | | | |
Share-Based Payment Arrangement, Option [Member] | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Dividend Rate | | | | | | | | | 0% | 0% | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term | | | | | | | | | 3 years 5 months 15 days | 5 years 8 months 26 days | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate | | | | | | | | | 49% | 50% | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate | | | | | | | | | 1.17% | 0.90% | | |
Share-Based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount | | | | | | | 3,820 | | $ 3,820 | | | |
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition | | | | | | | | | 3 years 6 months | | | |
Restricted Stock Units (RSUs) [Member] | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period | | 175,173 | | | | | | | 753,817 | | | |
Share-Based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount | | | | | | | $ 1,828 | | $ 1,828 | | | |
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition | | | | | | | | | 2 years 3 months 18 days | | | |
The 2017 Stock Incentive Plan [Member] | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized | 9,000,000 | | | | | | | | | | | 2,000,000 |
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Additional Shares Authorized | 1,500,000 | | | 1,500,000 | 1,900,000 | 2,100,000 | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant | | | | | | | 1,624,160 | | 1,624,160 | | | |
Share-Based Payment Arrangement, Accelerated Cost | | | $ 242 | | | | | | | | | |
The 2017 Stock Incentive Plan [Member] | Service-based Options [Member] | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number, Ending Balance | | | | | | | 4,022,083 | | 4,022,083 | | | |
The 2017 Stock Incentive Plan [Member] | Performance Shares [Member] | Chief Executive Officer and President [Member] | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross | | 1,614,230 | | | | | | | | | | |
Share Price | | $ 2.89 | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Term | | 10 years | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate | | 49% | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate | | 2.90% | | | | | | | | | | |
The 2017 Stock Incentive Plan [Member] | Performance Shares [Member] | Chief Executive Officer and President [Member] | Minimum [Member] | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Requisite Service Period | | 4 years | | | | | | | | | | |
The 2017 Stock Incentive Plan [Member] | Performance Shares [Member] | Chief Executive Officer and President [Member] | Maximum [Member] | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Requisite Service Period | | 7 years | | | | | | | | | | |
The 2017 Stock Incentive Plan [Member] | Performance Shares [Member] | Chief Executive Officer and President [Member] | Share-Based Payment Arrangement, Tranche One [Member] | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vesting, Sustained Market Capitalization | | $ 250,000 | | | | | | | | | | |
The 2017 Stock Incentive Plan [Member] | Performance Shares [Member] | Chief Executive Officer and President [Member] | Share-Based Payment Arrangement, Tranche Two [Member] | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vesting, Sustained Market Capitalization | | 500,000 | | | | | | | | | | |
The 2017 Stock Incentive Plan [Member] | Performance Shares [Member] | Chief Executive Officer and President [Member] | Share-Based Payment Arrangement, Tranche Three [Member] | | | | | | | | | | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vesting, Sustained Market Capitalization | | $ 1,000,000 | | | | | | | | | | |
The 2017 Stock Incentive Plan [Member] | Share-Based Payment Arrangement, Option [Member] | | | | | | | | | | | | |
Share-Based Payment Arrangement, Expense | | | | | | | $ 308 | 1,302 | $ 1,448 | $ 4,310 | | |
The 2017 Stock Incentive Plan [Member] | Restricted Stock Units (RSUs) [Member] | | | | | | | | | | | | |
Share-Based Payment Arrangement, Expense | | | | | | | $ 564 | $ 467 | $ 1,180 | $ 2,245 | | |