Note 5 - Income Taxes - Reconciliation of Effective Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Statement [Line Items]
Statutory provision	$ (286)	$ (765)
Foreign subsidiary	(162)	(4)
State taxes	86	180
Permanent differences	148	12
Adjustment to prior year taxes	(8)	93
Valuation allowance	394	844
Provision for income tax expense	$ 0	$ 0