Note 6 - Line of Credit and Long-term Debt - Summary of Line of Credit and Long-term Debt (Details) - USD ($)	Sep. 30, 2020	Mar. 31, 2020
Less current maturities	$ (4,197,000)	$ (2,689,000)
Long-term debt, excluding current maturities	5,704,000	6,178,000
Less unamortized debt issuance costs	(154,000)	(169,000)
Total long-term debt, net of current maturities and unamortized debt issuance costs	5,550,000	6,009,000
SBA CARES Act Paycheck Protection Program [Member]
Long-term debt	1,381,000
Line of Credit [Member]
Long-term debt	2,000,000	2,000,000
Long-term Debt, Excluding Related Party Debt [Member]
Long-term debt	5,020,000	5,367,000
Unsecured Subordinated Loan [Member]
Long-term debt	$ 1,500,000	$ 1,500,000