Note 9 - Segment and Geographic Information - Customers Comprising 10% of Consolidated Sales (Details) - Semiconductor Equipment [Member] - Revenue Benchmark [Member] - Customer Concentration Risk [Member]	12 Months Ended
	Dec. 28, 2019		Dec. 30, 2017
Intel [Member]
Net sales percentage	11.10%		11.20%
NXP Semiconductors N.V. [Member]
Net sales percentage		[1]	15.90%

[1] Less than 10% of consolidated net sales.