Note 7 - Stock-based Compensation (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)			0	0
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period (in shares)	0	0	0	667
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount	$ 162,308		$ 162,308
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Month)	11 months
Share-Based Payment Arrangement, Expense	$ 60,216	$ 88,159	$ 173,996	$ 376,331