Note 6 - Line of Credit and Long-term Debt - Summary of Line of Credit and Long-term Debt (Details) - USD ($)	Dec. 31, 2019	Mar. 31, 2019
Less current maturities	$ (2,700,000)	$ (2,663,000)
Long-term debt, excluding current maturities	6,349,000	5,372,000
Less unamortized debt issuance costs	(177,000)	(200,000)
Total long-term debt, net of current maturities and unamortized debt issuance costs	6,172,000	5,172,000
Line of Credit [Member]
Long-term debt	2,000,000	2,000,000
Long-term Debt, Excluding Related Party Debt [Member]
Long-term debt	5,549,000	6,035,000
Unsecured Subordinated Loan [Member]
Long-term debt	$ 1,500,000