Note 2 - Goodwill and Purchased Intangible Assets (Details Textual) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 27, 2020	Mar. 28, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019	Dec. 28, 2019
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)	$ 0		$ 0	$ 3,949	$ 0
Amortization of Intangible Assets, Total	9,527		$ 9,987	19,065	$ 20,006
In-process Technology [Member]
Indefinite-lived Intangible Assets (Excluding Goodwill), Ending Balance	$ 16,900			$ 16,900		$ 20,800
Indefinite-lived In Process Research and Development [Member]
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)		$ 3,900

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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Amount of impairment loss resulting from write-down of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit to fair value.

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Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit.

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