Note 7 - Stock-Based Compensation - Schedule of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Stock-based compensation expense	$ 965	$ 1,237
General and Administrative Expense [Member]
Stock-based compensation expense	$ 965	$ 1,237

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

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