Note 11 - Information As to Employee Stock Purchase, Savings, and Similar Plans (Details Textual) - USD ($)	3 Months Ended			6 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
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	$ 23,751		$ 26,831	$ 52,177	$ 55,415