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Note 8 - Share-based Payment Awards (Details Textual) - USD ($) |  | 3 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Dec. 31, 2018 | Mar. 31, 2026 | Mar. 31, 2025 | Jan. 01, 2026 | Dec. 31, 2025 | Dec. 31, 2024
Common Stock, Capital Shares Reserved for Future Issuance, Increase (in shares) |  |  |  | 1,081,882 |  | 1,068,323
Common Stock, Shares, Outstanding (in shares) |  | 27,359,791 |  |  | 27,047,061 | 26,709,084
Share-Based Payment Arrangement, Expense |  | $ 1,518,000 | $ 1,200,000 |  |  |
Share-Based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount |  | $ 9,166,000 |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period (in shares) |  | 272,597 | 108,451 |  |  |
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price (in dollars per share) |  | $ 5.13 | $ 3.63 |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period, Intrinsic Value |  | $ 3,473,000 | $ 1,167,000 |  |  |
Share-Based Payment Arrangement, Option [Member] |  |  |  |  |  |
Share-Based Payment Arrangement, Expense |  | $ 888,000 | 929,000 |  |  |
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year) |  | 3 years |  |  |  |
Restricted Stock Units (RSUs) [Member] |  |  |  |  |  |
Share-Based Payment Arrangement, Expense |  | $ 521,000 | 190,000 |  |  |
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year) |  | 3 years |  |  |  |
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount |  | $ 6,054 |  |  |  |
General and Administrative Expenses [Member] |  |  |  |  |  |
Share-Based Payment Arrangement, Expense |  | 1,469,000 | 1,161,000 |  |  |
Research and Development Expenses [Member] |  |  |  |  |  |
Share-Based Payment Arrangement, Expense |  | $ 49,000 | 39,000 |  |  |
The 2018 Plan [Member] |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares) |  | 1,301,548 |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Annual Increase in Share Reserve as a Percent of Outstanding Common Stock |  | 4.00% |  |  |  |
The 2018 Employee Stock Purchase Plan [Member] |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares) |  | 975,687 |  |  |  |
Common Stock, Capital Shares Reserved for Future Issuance, Increase (in shares) | 150,000 |  |  |  |  |
Share-Based Payment Arrangement, Expense |  | $ 109,000 | $ 81,000 |  |  |
Common Stock, Capital Shares Reserved for Future Issuance (in shares) | 150,000 |  |  |  |  |
Common Stock, Capital Shares Reserved for Future Issuance, Percentage Increase | 1.00% |  |  |  |  |
Employee Stock Purchase Plans, Fair Value of Common Stock Price Per Share on Offering Date, Percentage | 85.00% |  |  |  |  |
Employee Stock Purchase Plans, Fair Value of Common Stock Price Per Share on Purchase Date, Percentage | 85.00% |  |  |  |  |
Employee-related Liabilities, Current |  | $ 258,000 |  |  | $ 45,000 |

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