Note 9 - Stock-Based Compensation - Stock-based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 28, 2020	Mar. 30, 2019
Total stock-based compensation	$ 8,728	$ 3,686
Cost of Sales [Member]
Total stock-based compensation	591	202
Research and Development Expense [Member]
Total stock-based compensation	2,594	1,125
Selling, General and Administrative Expenses [Member]
Total stock-based compensation	$ 5,543	$ 2,359

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

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