Note 9 - Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Mar. 31, 2025
Operating lease expense	$ 116	$ 23	$ 233	$ 33
Short-term lease expense	0	0	0	3
Total lease cost	116	$ 23	233	$ 36
Operating lease right-of-use assets	2,823		2,823		$ 2,963
Operating lease liability - current portion	296		296		286
Operating lease liability	$ 2,538		$ 2,538		$ 2,685