Note 10 - Income Taxes (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Tax Expense (Benefit), Total	$ 0	$ 11,000	$ 3,000	$ 14,000
Effective Income Tax Rate Reconciliation, Percent, Total	0.00%	1.10%	0.00%	1.00%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			21.00%
Unrecognized Tax Benefits, Ending Balance	$ 0		$ 0