Note 6 - Stockholders' Equity - Summary of Additional Information About Stock Options Outstanding and Exercisable (Details) - USD ($)	6 Months Ended
Jun. 30, 2025	Dec. 31, 2024	Jun. 30, 2024	Dec. 31, 2023
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number (in shares)	113,750	113,750	99,750	119,750
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term (Year)	3 years 9 months 18 days
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 3.27	$ 3.27	$ 3.25	$ 2.97
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value	$ 297,143
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Number (in shares)	113,750		99,750
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 3.27		$ 3.25
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Intrinsic Value	$ 297,143

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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-Name Accounting Standards Codification
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-SubTopic 10
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Number of options outstanding, including both vested and non-vested options.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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