Note 8 - Stock-based Compensation (Details Textual) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares)	265,000	30,000	1,177,000	302,500
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Grant Date Fair Value	$ 157,300	$ 34,500	$ 2,231,970	$ 363,550
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period (in shares)	107,000	65,000	264,000	450,000
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total	$ 2,019,066		$ 2,019,066
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Month)			9 months 12 days
Share-Based Payment Arrangement, Expense	$ 614,094	$ 80,882	$ 1,455,835	$ 220,455