Note 2 - Goodwill and Purchased Intangible Assets - Purchased Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 26, 2022	Dec. 25, 2021
Gross Carrying Amount, finite-lived intangible assets	$ 312,222	$ 316,232
Accumulated Amortization	145,479	138,912
Developed Technology Rights [Member]
Gross Carrying Amount, finite-lived intangible assets	226,203	229,131
Accumulated Amortization	$ 110,082	104,855
Remaining Useful Life (Year)	4 years 3 months 18 days
Customer Relationships [Member]
Gross Carrying Amount, finite-lived intangible assets	$ 65,123	65,916
Accumulated Amortization	$ 27,175	26,189
Remaining Useful Life (Year)	7 years 2 months 12 days
Trade Names [Member]
Gross Carrying Amount, finite-lived intangible assets	$ 20,607	20,877
Accumulated Amortization	$ 8,071	7,714
Remaining Useful Life (Year)	7 years 1 month 6 days
Noncompete Agreements [Member]
Gross Carrying Amount, finite-lived intangible assets	$ 289	308
Accumulated Amortization	$ 151	$ 154
Remaining Useful Life (Year)	4 years 9 months 18 days