Note 2 - Goodwill and Purchased Intangible Assets - Purchased Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 25, 2021	Dec. 26, 2020
Developed Technology Rights [Member]
Gross Carrying Amount, finite-lived intangible assets	$ 229,131	$ 239,250
Accumulated Amortization	$ 104,855	83,246
Remaining Useful Life (Year)	4 years 6 months
Customer Relationships [Member]
Gross Carrying Amount, finite-lived intangible assets	$ 65,916	74,933
Accumulated Amortization	$ 26,189	22,751
Remaining Useful Life (Year)	7 years 4 months 24 days
Trade Names [Member]
Gross Carrying Amount, finite-lived intangible assets	$ 20,877	23,756
Accumulated Amortization	$ 7,714	6,279
Remaining Useful Life (Year)	7 years 3 months 18 days
Noncompete Agreements [Member]
Gross Carrying Amount, finite-lived intangible assets	$ 308	340
Accumulated Amortization	$ 154	$ 136
Remaining Useful Life (Year)	5 years