Note 9 - Leases - Summary of Components of Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2024	Dec. 31, 2023
Lease cost
Operating lease cost	$ 45	$ 52	$ 145	$ 141
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	46	43	141	123
Right-of-use assets obtained in exchange for lease obligations:
Right-of-use assets obtained in exchange for new operating lease liabilities	0	0	313	248
Right-of-use assets obtained in exchange for new finance lease liabilities	$ 0	$ 0	$ 6	$ 0