Note 10 - Segment and Geographic Information - Summary of Net Sales to Customers, Attributed to Countries (Details) - USD ($) $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 26, 2020	[1]	Sep. 26, 2020	[1]	Jun. 27, 2020	[1]	Mar. 28, 2020	[1]	Dec. 28, 2019	[1]	Sep. 28, 2019	[1]	Jun. 29, 2019	[1]	Mar. 30, 2019	[1]	Dec. 26, 2020	Dec. 28, 2019	Dec. 29, 2018
Net sales	$ 202,355		$ 150,647		$ 144,084		$ 138,921		$ 142,011		$ 143,498		$ 150,011		$ 147,809		$ 636,007	$ 583,329	$ 451,768
CHINA
Net sales																	143,360	118,213	90,255
UNITED STATES
Net sales																	108,694	71,963	61,177
TAIWAN, PROVINCE OF CHINA
Net sales																	83,685	75,725	25,074
Malaysia [Member]
Net sales																	57,893	61,826	61,793
PHILIPPINES
Net sales																	56,272	51,683	46,421
Rest of the World [Member]
Net sales																	$ 186,103	$ 203,919	$ 167,048

[1] All quarters presented above were comprised of 13 weeks.