Note 15 - Retirement Savings Plans (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Contribution Plan, Employer Matching Contribution, Percent of Match			100.00%	100.00%
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent			4.00%	4.00%
Defined Contribution Plan, Employer Contribution Amount	$ 127,953	$ 119,555
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 0	$ 0