Note 7 - Debt and Other Financing Arrangements (Details Textual) - USD ($)		1 Months Ended	3 Months Ended	9 Months Ended
	May 01, 2020	Jul. 31, 2021	Sep. 30, 2021	Sep. 30, 2021	Sep. 30, 2020
Proceeds from Issuance of Long-term Debt, Total					$ 2,181,000
Gain (Loss) on Extinguishment of Debt, Total		$ 2.1	$ 2,181,000	$ 2,181,000
Paycheck Protection Program CARES Act [Member]
Proceeds from Issuance of Long-term Debt, Total	$ 2.1
Line of Credit [Member] | Equipment Loan Arrangement [Member] | Banc of America Leasing and Capital [Member]
Long-term Debt, Weighted Average Interest Rate, over Time			3.50%	3.40%
Interest Expense, Total			$ 12,000	$ 38,000
Long-term Debt, Weighted Average Interest Rate, at Point in Time			3.10%	3.10%
Long-term Debt, Total			$ 1,400,000	$ 1,400,000