Note 11 - Information As to Employee Stock Purchase, Savings, and Similar Plans (Details Textual) - USD ($)	3 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	100.00%
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent	3.00%
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 28,584	$ 25,381