Note 1 - Significant Accounting Policies - Allowance for Credit Loss (Details) - USD ($)	6 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Balance	$ (1,107,000)	$ (29,000)
Reserve adjustment	(6,000)	(8,000)
Balance	$ (1,113,000)	$ (37,000)