Note 14 - Equity Incentive Plan - Total Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Stock-based compensation expense	$ 5,386	$ 6,087	$ 11,046
Cost of Sales [Member]
Stock-based compensation expense	719	412	(160)
Research and Development Expense [Member]
Stock-based compensation expense	713	424	851
Selling, General and Administrative Expenses [Member]
Stock-based compensation expense	$ 3,954	$ 5,251	$ 10,355

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

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