Note 11 - Income Taxes (Details Textual) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Mar. 31, 2019
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent					21.00%
Income Tax Expense (Benefit), Total	$ 32,000	$ 73,000	$ 29,000	$ 33,000
Effective Income Tax Rate Reconciliation, Percent, Total	15.80%	20.20%	9.70%	(1.60%)
Unrecognized Tax Benefits, Ending Balance	$ 0	$ 0	$ 0	$ 0