Note 12 - Summary of Stock Options - Stock-based Compensation Expense Included in the Statement of Income (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Stock-based compensation expense	$ 2,400	$ 3,035
Cost of Sales [Member]
Stock-based compensation expense	135	69
Research and Development Expense [Member]
Stock-based compensation expense	192	328
Selling, General and Administrative Expenses [Member]
Stock-based compensation expense	$ 2,073	$ 2,638

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

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