Note 2 - Goodwill and Purchased Intangible Assets - Purchased Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2020	Dec. 28, 2019
Gross Carrying Amount, finite-lived intangible assets	$ 322,870	$ 322,804
Accumulated Amortization	78,438	68,617
Developed Technology Rights [Member]
Gross Carrying Amount, finite-lived intangible assets	228,061	227,619
Accumulated Amortization	$ 57,557	49,805
Remaining Useful Life (Year)	6 years 146 days
Customer Relationships [Member]
Gross Carrying Amount, finite-lived intangible assets	$ 71,778	72,251
Accumulated Amortization	$ 16,332	14,824
Remaining Useful Life (Year)	9 years 36 days
Trade Names [Member]
Gross Carrying Amount, finite-lived intangible assets	$ 22,704	22,612
Accumulated Amortization	$ 4,443	3,892
Remaining Useful Life (Year)	9 years 109 days
Noncompete Agreements [Member]
Gross Carrying Amount, finite-lived intangible assets	$ 327	322
Accumulated Amortization	$ 106	$ 96
Remaining Useful Life (Year)	6 years 292 days