Note 1 - Significant Accounting Policies - Allowance for Credit Loss (Details) - USD ($)	3 Months Ended
	Jun. 30, 2025	Jun. 30, 2024
Balance	$ (1,107,000)	$ (25,000)
Reserve adjustment	(9,000)	(4,000)
Balance	$ (1,116,000)	$ (29,000)