Note 5 - Stock-based Compensation - Stock Options Outstanding and Exercisable (Details)	3 Months Ended	6 Months Ended
	Jun. 30, 2025 USD ($) $ / shares shares	Jun. 30, 2025 USD ($) $ / shares shares
Share-Based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit (in dollars per share)	$ 3.5
Share-Based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit	$ 39.11
Share-Based Payment Arrangement, Option, Exercise Price Range, Shares Outstanding | shares	59,000	59,000
Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Remaining Contractual Term		3 years 1 month 6 days
Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Exercise Price	$ 17.35	$ 17.35
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value | $	$ 766,630	$ 766,630
Options Outstanding Exercise Price Range1 [Member]
Share-Based Payment Arrangement, Option, Exercise Price Range, Lower Range Limit (in dollars per share)	$ 3.5
Share-Based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit	$ 3.86
Share-Based Payment Arrangement, Option, Exercise Price Range, Shares Outstanding | shares	13,000	13,000
Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Remaining Contractual Term		1 year 8 months 12 days
Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Exercise Price	$ 3.75	$ 3.75
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value | $	$ 327,870	$ 327,870
Options Outstanding Exercise Price Range2 [Member]
Share-Based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit		$ 7.8
Share-Based Payment Arrangement, Option, Exercise Price Range, Shares Outstanding | shares	8,000	8,000
Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Remaining Contractual Term		2 years 10 months 24 days
Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Exercise Price	$ 7.8	$ 7.8
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value | $	$ 169,360	$ 169,360
Options Outstanding Exercise Price Range 3 [Member]
Share-Based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit		$ 19.99
Share-Based Payment Arrangement, Option, Exercise Price Range, Shares Outstanding | shares	30,000	30,000
Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Remaining Contractual Term		3 years 7 months 6 days
Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Exercise Price	$ 19.99	$ 19.99
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value | $	$ 269,400	$ 269,400
Options Outstanding Exercise Price Range 4 [Member]
Share-Based Payment Arrangement, Option, Exercise Price Range, Upper Range Limit		$ 39.11
Share-Based Payment Arrangement, Option, Exercise Price Range, Shares Outstanding | shares	8,000	8,000
Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Remaining Contractual Term		3 years 10 months 24 days
Share-Based Payment Arrangement, Option, Exercise Price Range, Outstanding, Weighted Average Exercise Price	$ 39.11	$ 39.11
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Intrinsic Value | $	$ 0	$ 0