Note 1 - Background and Basis of Presentation - Accounts Receivable (Details) - USD ($)	Jun. 30, 2026	Mar. 31, 2026	Mar. 31, 2025
Trade receivables	$ 930,000	$ 1,300,000	$ 2,606,000
Allowance for credit losses	(3,000)	(7,000)	(1,107,000)
Accounts receivable, net	$ 927,000	$ 1,293,000	$ 1,499,000