Note 9 - Segment and Geographic Information - Summary of Net Sales to Customers, Attributed to Countries (Details) - USD ($) $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 29, 2018	[1],[2]	Sep. 29, 2018	[1],[2]	Jun. 30, 2018	[1],[2]	Mar. 31, 2018	[1],[2]	Dec. 30, 2017	[1],[2]	Sep. 30, 2017	[1]	Jul. 01, 2017	[1]	Apr. 01, 2017	[1]	Dec. 29, 2018		Dec. 30, 2017	Dec. 31, 2016
Net sales	$ 170,637		$ 86,164		$ 99,817		$ 95,150		$ 84,090		$ 93,651		$ 93,866		$ 81,097		$ 451,768	[1],[2]	$ 352,704	$ 282,084
CHINA
Net sales																	90,255		82,474	60,291
Malaysia [Member]
Net sales																	61,793		80,102	85,956
UNITED STATES
Net sales																	61,177		38,729	35,204
PHILIPPINES
Net sales																	46,421		26,268	16,922
Rest of the World [Member]
Net sales																	$ 192,122		$ 125,131	$ 83,711

[1] All quarters presented above were comprised of 13 weeks, except for the first quarter ended March 25, 2017, and the third quarter ended September 30, 2017, which were comprised of 12 and 14 weeks, respectively.

[2] We acquired Xcerra on October 1, 2018. The results of Xcerra have been included in our results of operations from the date of acquisition. See Note 2, "Business Acquisitions" for additional information regarding this transaction. Total operating expenses in the fourth quarter of 2018 include charges related to the acquisition of Xcerra as follows - $37.8 million in restructuring charges comprised of $19.1 million of inventory end-of-manufacturing write-downs related to one of Xcerra's products, employee severance costs of $17.8 million and $0.9 million for other restructuring costs. We also recorded $13.1 million for the amortization of acquisition-related intangibles.