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Note 7 - Stockholders' Equity (Deficit) (Details Textual) |  |  |  |  | 6 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Jun. 10, 2024 USD ($) $ / shares shares | Jul. 24, 2023 USD ($) $ / shares shares | May 09, 2023 USD ($) $ / shares shares | Jan. 19, 2023 USD ($) $ / shares shares | Dec. 31, 2023 USD ($) $ / shares shares | Dec. 31, 2024 USD ($) $ / shares shares | Dec. 31, 2023 USD ($) $ / shares shares | Jun. 30, 2023 USD ($) shares | Jul. 26, 2023 $ / shares | Jun. 08, 2023 USD ($)
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Common Stock, Shares Authorized (in shares) |  |  |  |  | 45,000,000 | 45,000,000 | 45,000,000 |  |  |
Preferred Stock, Shares Authorized (in shares) |  |  |  |  | 15,000,000 | 15,000,000 | 15,000,000 |  |  |
Common Stock, Shares, Outstanding (in shares) |  |  |  |  | 9,451,753 | 12,228,479 | 9,451,753 |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number (in shares) |  |  |  |  |  | 436,863 |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options and Warrants, Outstanding, Number (in shares) |  |  |  |  |  | 826,375 |  |  |  |
Preferred Stock, Shares Issued (in shares) |  |  |  |  |  | 0 |  |  |  |
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares |  |  | $ 0.01 |  | $ 0.01 | $ 0.01 | $ 0.01 |  |  |
Proceeds from Warrant Exercises | $ |  |  |  |  | $ 0 | $ 0 | $ 6,886,000 | $ 6,886,000 |  |
January 2023 Warrants [Member] | Measurement Input, Risk Free Interest Rate [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input |  |  |  | 0.0465 |  |  |  |  |  |
January 2023 Warrants [Member] | Measurement Input, Expected Term [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input |  |  |  | 1 |  |  |  |  |  |
January 2023 Warrants [Member] | Measurement Input, Price Volatility [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input |  |  |  | 0.404 |  |  |  |  |  |
January 2023 Warrants [Member] | Measurement Input, Expected Dividend Rate [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input |  |  |  | 0 |  |  |  |  |  |
December 2022 and January 2023 Warrants [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares |  |  | $ 25 |  |  |  |  |  |  |
Class of Warrant or Right, Exercised During Period (in shares) |  |  | 313,000 |  |  |  |  |  |  |
Proceeds from Warrant Exercises | $ |  |  | $ 6,900,000 |  |  |  |  |  |  |
Stock Issued During Period, Shares, Warrants Exercised (in shares) |  |  | 313,000 |  |  |  |  |  |  |
Fair Value Adjustment of Warrants | $ |  |  | $ 383,000 |  |  |  |  |  |  |
December 2022 and January 2023 Warrants [Member] | Measurement Input, Risk Free Interest Rate [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input |  |  | 4.81 |  |  |  |  |  |  |
December 2022 and January 2023 Warrants [Member] | Measurement Input, Expected Term [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input |  |  | 1 |  |  |  |  |  |  |
December 2022 and January 2023 Warrants [Member] | Measurement Input, Price Volatility [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input |  |  | 42.5 |  |  |  |  |  |  |
December 2022 and January 2023 Warrants [Member] | Measurement Input, Expected Dividend Rate [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input |  |  | 0 |  |  |  |  |  |  |
Modified Warrants [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares |  |  | $ 22 |  |  |  |  |  |  |
New Warrants [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares |  |  | $ 30 |  |  |  |  |  |  |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) |  |  | 313,000 |  |  |  |  |  |  |
New Warrants [Member] | Measurement Input, Risk Free Interest Rate [Member] | Fair Value, Inputs, Level 2 [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input |  |  | 4.81 |  |  |  |  |  |  |
New Warrants [Member] | Measurement Input, Expected Term [Member] | Fair Value, Inputs, Level 2 [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input |  |  | 1.5 |  |  |  |  |  |  |
New Warrants [Member] | Measurement Input, Price Volatility [Member] | Fair Value, Inputs, Level 2 [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input |  |  | 43.7 |  |  |  |  |  |  |
New Warrants [Member] | Measurement Input, Expected Dividend Rate [Member] | Fair Value, Inputs, Level 2 [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input |  |  | 0 |  |  |  |  |  |  |
Sales Agreement [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Stock Issued During Period, Shares, New Issues (in shares) |  |  |  |  | 52,915 | 87,815 |  | 158,461 |  |
Proceeds from Issuance of Common Stock, Net | $ |  |  |  |  | $ 1,100,000 | $ 1,800,000 |  | $ 4,100,000 |  |
Balance remaining from sales agreement | $ |  |  |  |  |  | $ 33,000,000 |  |  |  |
Private Placement [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Stock Issued During Period, Shares, New Issues (in shares) |  |  |  | 117,500 |  |  |  |  |  |
Proceeds from Issuance of Common Stock, Net | $ |  |  |  | $ 2,300,000 |  |  |  |  |  |
Rights Agreement, Exercise Price (in dollars per share) | $ / shares |  |  |  | $ 25 |  |  |  |  |  |
Private Placement Fee, Percentage |  |  |  | 3.25% |  |  |  |  |  |
Private Placement [Member] | January 2023 Warrants [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Shares Issued, Price Per Share (in dollars per share) | $ / shares |  |  |  | $ 20 |  |  |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares |  |  |  | $ 25 |  |  |  |  |  |
Underwritten Public Offering [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Stock Issued During Period, Shares, New Issues (in shares) | 731,750 | 1,600,000 |  |  |  |  |  |  |  |
Proceeds from Issuance of Common Stock, Net | $ | $ 13,700,000 | $ 28,200,000 |  |  |  |  |  |  |  |
Shares Issued, Offering Price (in dollars per share) | $ / shares |  | $ 19 |  |  |  |  |  |  |  |
Shares Issued, Price Per Share (in dollars per share) | $ / shares | $ 20.5 |  |  |  |  | $ 19.37 |  |  | $ 17.77 |
Warrant exercise price | $ / shares | $ 26 |  |  |  |  |  |  |  |  |
Warrants exercisable term | 36 months |  |  |  |  |  |  |  |  |
Underwriting Agreement, Discount Percentage |  | 6.50% |  |  |  | 5.50% |  |  |  |
Underwritten Public Offering [Member] | Measurement Input, Risk Free Interest Rate [Member] | Fair Value, Inputs, Level 2 [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input | 4.57 |  |  |  |  |  |  |  |  |
Underwritten Public Offering [Member] | Measurement Input, Expected Term [Member] | Fair Value, Inputs, Level 2 [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input | 3 |  |  |  |  |  |  |  |  |
Underwritten Public Offering [Member] | Measurement Input, Price Volatility [Member] | Fair Value, Inputs, Level 2 [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input | 57 |  |  |  |  |  |  |  |  |
Underwritten Public Offering [Member] | Measurement Input, Expected Dividend Rate [Member] | Fair Value, Inputs, Level 2 [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Warrants and Rights Outstanding, Measurement Input | 0 |  |  |  |  |  |  |  |  |
Cantor Fitzgerald & Co. [Member] | Sales Agreement [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Offering Agreement, Maximum Aggregate Common Shares May be Offered | $ |  |  |  |  |  |  |  |  |  | $ 40,000,000
Commission Fee, Percentage of Gross Proceeds of Shares Sold, Maximum |  |  |  |  |  |  |  |  |  | 2.75%
Restricted Stock [Member] |  |  |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number (in shares) |  |  |  |  | 433,528 | 436,863 | 433,528 | 429,376 |  |

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