Note 9 - Stock-Based Compensation - Stock-based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Total stock-based compensation	$ 11,012	$ 3,969	$ 19,740	$ 7,655
Cost of Sales [Member]
Total stock-based compensation	897	327	1,488	529
Research and Development Expense [Member]
Total stock-based compensation	2,234	1,246	4,828	2,371
Selling, General and Administrative Expenses [Member]
Total stock-based compensation	$ 7,881	$ 2,396	$ 13,424	$ 4,755

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

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