Note 4 - Financing Arrangements - Long-term Debt (Details) (Parentheticals) - Real Estate Term Note [Member] - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2021	Dec. 31, 2020
Interest rate	2.10%	4.30%
Monthly payments	$ 41	$ 41
London Interbank Offered Rate (LIBOR) [Member]
Variable rate basis	2.00%	2.00%

Contractual interest rate for funds borrowed, under the debt agreement.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of the required periodic payments including both interest and principal payments.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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The percentage points added to the reference rate to compute the variable rate on the interest rate derivative.

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No definition available.

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