Note 7 - Income Taxes (Details Textual) - USD ($)	12 Months Ended
Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation		$ 32,616	$ 352,294
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability	$ 206,693
Unrecognized Tax Benefits, Ending Balance	0
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	0
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	$ 0
Open Tax Year	1999
Earliest Tax Year [Member]
Open Tax Year	2013
Latest Tax Year [Member]
Open Tax Year	2016

Amount of increase in additional paid in capital (APIC) resulting from a tax benefit associated with share-based compensation plan other than an employee stock ownership plan (ESOP). Includes, but is not limited to, excess tax benefit.

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Amount of income tax expense (benefit) from continuing operations attributable to an adjustment of a deferred tax liability or asset for enacted changes in tax laws or rates or a change in the tax status of the entity.

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Tax year that remains open to examination under enacted tax laws, in CCYY format.

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Amount of unrecognized tax benefits.

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Amount of interest expense accrued for an underpayment of income taxes.

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