Note 9 - Leases - Summary of Components of Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Lease cost
Operating lease cost	$ 37	$ 59
Finance lease cost	0	0
Amortization of right-of-use assets	0	0
Interest on lease liabilities	0	0
Variable lease costs	0	0
Total lease cost	37	59
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	37	59
Operating cash flows from finance leases	0	0
Financing cash flows from finance leases	0	0
Right-of-use assets obtained in exchange for lease obligations:
Operating leases	0	0
Finance leases	$ 0	$ 0