Note 8 - Segment and Geographic Information - Customers Comprising 10% of Consolidated Sales (Details) - Semiconductor Equipment [Member] - Sales Revenue, Net [Member] - Customer Concentration Risk [Member]		12 Months Ended
		Dec. 31, 2016	Dec. 26, 2015	Dec. 27, 2014
Intel [Member]
Net sales percentage		17.20%	18.00%	15.70%
NXP Semiconductors N.V. [Member]
Net sales percentage	[1]	13.70%	11.40%	11.40%

[1] The merger of NXP Semiconductors N.V. and Freescale Semiconductor, Ltd. was completed on December 7, 2015. Sales to these customers have been combined for all periods presented.