Note 6 - Stockholders' Equity - Summary of Additional Information About Stock Options Outstanding and Exercisable (Details) - USD ($)	3 Months Ended
Mar. 31, 2026	Dec. 31, 2025	Mar. 31, 2025	Dec. 31, 2024
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number (in shares)	124,500	128,250	113,750	115,750
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term (Year)	3 years 8 months 15 days
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 3.34	$ 3.36	$ 3.27	$ 3.28
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value	$ 159,760
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Number (in shares)	124,500		113,750
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 3.34		$ 3.27
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Intrinsic Value	$ 159,760

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

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