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Note 5 - Stockholders' Equity (Details Textual) $ / shares in Units, $ in Millions | 3 Months Ended | 6 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Mar. 31, 2025 shares | Jun. 30, 2025 USD ($) Milestone $ / shares shares | Dec. 31, 2024 USD ($) $ / shares shares | Apr. 16, 2019 shares
Equity [Line Items] |  |  |  |
Preferred Stock, Shares Authorized (in shares) |  | 5,000,000 | 5,000,000 |
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares |  | $ 0.0001 | $ 0.0001 |
Preferred Stock, Shares Issued (in shares) |  | 0 | 0 |
Common Stock, Shares Authorized (in shares) |  | 500,000,000 | 500,000,000 |
Common Stock, Shares, Issued (in shares) |  | 26,777,198 | 26,529,402 |
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares |  | $ 0.0001 | $ 0.0001 |
Additional Paid in Capital | $ |  | $ 509.2 | $ 493.7 |
Number of Stock Price Milestones Achieved | Milestone |  | 4 |  |
Number Of Additional Stock Price Milestones Achieved | Milestone |  | 2 |  |
Issuance of common stock via employee stock purchase plan (in shares) |  | 6,310 |  |
Treasury Stock, Shares, Acquired (in shares) | 0 |  |  |
Preferred Stock, Shares Outstanding (in shares) |  | 0 | 0 |
Common Stock, Shares, Outstanding (in shares) |  | 26,777,198 | 26,529,402 |
Employee Stock Option [Member] |  |  |  |
Equity [Line Items] |  |  |  |
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year) |  | 3 months 18 days |  |
Employee Stock Option [Member] | Share-Based Payment Arrangement, Tranche One [Member] | Minimum [Member] |  |  |  |
Equity [Line Items] |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) |  | 2 years |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage |  | 25.00% |  |
Employee Stock Option [Member] | Share-Based Payment Arrangement, Tranche One [Member] | Maximum [Member] |  |  |  |
Equity [Line Items] |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) |  | 4 years |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage |  | 50.00% |  |
Restricted Stock Units (RSUs) [Member] |  |  |  |
Equity [Line Items] |  |  |  |
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year) |  | 1 year 9 months 18 days |  |
Share-Based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount | $ |  | $ 22.2 |  |
Restricted Stock Units (RSUs) [Member] | Minimum [Member] |  |  |  |
Equity [Line Items] |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) |  | 1 year |  |
Restricted Stock Units (RSUs) [Member] | Maximum [Member] |  |  |  |
Equity [Line Items] |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period (Year) |  | 5 years |  |
Performance Shares [Member] |  |  |  |
Equity [Line Items] |  |  |  |
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year) |  | 1 year 4 months 24 days |  |
Share-Based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount | $ |  | $ 13.0 |  |
Predetermined Performance Achievement, Percentage |  | 100.00% |  |
Performance Shares [Member] | Share-Based Payment Arrangement, Tranche One [Member] |  |  |  |
Equity [Line Items] |  |  |  |
Number of Days, Achievement of Milestone Stock Price | Milestone |  | 30 |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Service Period (Year) |  | 5 years |  |
Performance Shares [Member] | Share-Based Payment Arrangement, Tranche Two [Member] |  |  |  |
Equity [Line Items] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Service Period (Year) |  |  | 3 years |
Employee Stock [Member] |  |  |  |
Equity [Line Items] |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares) |  |  |  | 240,000
Share-based Compensation Arrangement by Share-based Payment Award, Shares Available for Issuance, Authorized Annual Increase, Maximum (in shares) |  |  |  | 240,000
Equity Incentive Plan 2019 [Member] |  |  |  |
Equity [Line Items] |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized (in shares) |  | 4,225,816 |  | 2,400,000
Share Based Compensation Arrangement By Share Based Payment Award Percentage, Number of Additional Shares Available for Grant |  |  |  | 3.00%

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