Note 8 - Stock-based Compensation - Components of Stock-based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Stock options and restricted stock units, net of forfeited	$ 20	$ 81
After-tax effect of stock-based compensation	$ 20	$ 81

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

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