Note 8 - Stock-based Compensation - Stock-based Compensation (Details) - Selling, General and Administrative Expenses [Member] - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Stock options and restricted stock units, net of forfeited	$ 21	$ 57	$ 61	$ 207
After-tax effect of stock-based compensation	$ 21	$ 57	$ 61	$ 207

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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-Name Accounting Standards Codification
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-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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