Note J - Income Taxes (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Tax Expense (Benefit), Total	$ 644,709	$ 184,927	$ 1,807,329	$ 329,888
Effective Income Tax Rate Reconciliation, Percent, Total			24.40%	30.30%