Note 2 - Goodwill and Purchased Intangible Assets - Purchased Intangible Assets (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 26, 2020	Dec. 28, 2019
Gross Carrying Amount, finite-lived intangible assets	$ 330,095	$ 322,804
Accumulated Amortization	99,582	68,617
Developed Technology Rights [Member]
Gross Carrying Amount, finite-lived intangible assets	233,442	227,619
Accumulated Amortization	$ 73,584	49,805
Remaining Useful Life (Year)	6 years
Customer Relationships [Member]
Gross Carrying Amount, finite-lived intangible assets	$ 73,165	72,251
Accumulated Amortization	$ 20,282	14,824
Remaining Useful Life (Year)	8 years 8 months 12 days
Trade Names [Member]
Gross Carrying Amount, finite-lived intangible assets	$ 23,154	22,612
Accumulated Amortization	$ 5,591	3,892
Remaining Useful Life (Year)	8 years 10 months 24 days
Noncompete Agreements [Member]
Gross Carrying Amount, finite-lived intangible assets	$ 334	322
Accumulated Amortization	$ 125	$ 96
Remaining Useful Life (Year)	6 years 3 months 18 days