Note 3 - Goodwill and Other Purchased Intangible Assets - Purchased Intangible Assets, Subject to Amortization (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016
Gross Carrying Amount	$ 35,212	$ 31,544
Accumulated Amortization	18,464	13,709
Developed Technology Rights [Member]
Gross Carrying Amount	20,780	19,194
Accumulated Amortization	$ 12,623	9,597
Remaining Useful Life (Year)	3 years 109 days
Customer Relationships [Member]
Gross Carrying Amount	$ 7,934	6,996
Accumulated Amortization	$ 4,838	3,644
Remaining Useful Life (Year)	3 years
Trade Names [Member]
Gross Carrying Amount	$ 6,185	5,354
Accumulated Amortization	$ 972	468
Remaining Useful Life (Year)	12 years 73 days
Noncompete Agreements [Member]
Gross Carrying Amount	$ 313
Accumulated Amortization	$ 31
Remaining Useful Life (Year)	9 years