Note 9 - Leases - Summary of Components of Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Lease cost
Operating lease cost	$ 62	$ 63	$ 125	$ 127
Finance lease cost	0	0	0	0
Amortization of right-of-use assets	0	0	0	0
Interest on lease liabilities	0	0	0	0
Variable lease costs	0	0	0	0
Total lease cost	62	63	125	127
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	62	64	125	131
Operating cash flows from finance leases	0	0	0	0
Financing cash flows from finance leases	0	0	0	0
Right-of-use assets obtained in exchange for lease obligations:
Operating leases	0	403	0	403
Finance leases	$ 0	$ 0	$ 0	$ 0