Note 3 - Goodwill and Purchased Intangible Assets (Details Textual) $ in Thousands	3 Months Ended										12 Months Ended
	Dec. 29, 2018 USD ($)	Dec. 29, 2018 USD ($)	Dec. 29, 2018 USD ($)	Sep. 29, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 30, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jul. 01, 2017 USD ($)	Apr. 01, 2017 USD ($)	Dec. 29, 2018 USD ($)	Dec. 30, 2017 USD ($)	Dec. 31, 2016 USD ($)
Number of Reportable Segments	2	2									2
Amortization of Intangible Assets, Total			$ 11,600	$ 600	$ 700	$ 700	$ 700	$ 700	$ 600	$ 700	$ 17,197	$ 4,208	$ 6,903
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	$ 38,900	$ 38,900	38,900								38,900
Finite-Lived Intangible Assets, Amortization Expense, Year Two	37,100	37,100	37,100								37,100
Finite-Lived Intangible Assets, Amortization Expense, Year Three	33,800	33,800	33,800								33,800
Finite-Lived Intangible Assets, Amortization Expense, Year Four	33,700	33,700	33,700								33,700
Finite-Lived Intangible Assets, Amortization Expense, Year Five	33,400	33,400	33,400								33,400
Finite-Lived Intangible Assets, Amortization Expense, after Year Five	105,800	105,800	105,800								105,800
In-process Technology [Member]
Indefinite-lived Intangible Assets (Excluding Goodwill), Ending Balance	$ 36,300	$ 36,300	$ 36,300								$ 36,300