Note 13 - Stock-based Compensation - Summary of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Payment Arrangement, Expense	$ 2,197	$ 2,260	$ 3,090
Stock Options [Member]
Share-based Payment Arrangement, Expense	307	174	0
Restricted Stock Units and Performance Share Units [Member]
Share-based Payment Arrangement, Expense	$ 1,890	$ 2,086	$ 3,090

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

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