Note 2 - Cash, Cash Equivalents, and Investments (Details Textual) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Corporate Debt Securities [Member]
Debt Securities, Held-to-maturity, Premium Paid on Purchase	$ 20,850	$ 283,940	$ 283,940