Note 15 - Business Unit Segment Information - Revenues and Long-lived Assets by Geographical Area (Details) - USD ($) $ in Thousands		3 Months Ended		12 Months Ended
		Jan. 02, 2016	Dec. 27, 2014	Jan. 02, 2016	Jan. 02, 2016	Dec. 27, 2014	Dec. 28, 2013
UNITED STATES
Net sales
Net sales	[1]				$ 344,305	$ 313,762	$ 274,666
Long-lived assets:
Long-lived assets		$ 23,965	$ 34,179	$ 23,965	23,965	34,179	27,294
Additions to long-lived assets					8,609	9,134	4,644
CHINA
Net sales
Net sales	[1]				193,792	189,191	158,494
Long-lived assets:
Long-lived assets		37,241	40,981	37,241	37,241	40,981	45,843
Additions to long-lived assets					9,710	7,265	7,864
Other Countries [Member]
Net sales
Net sales	[1]				329,767	349,042	324,693
Long-lived assets:
Long-lived assets		90,874	70,581	90,874	90,874	70,581	62,607
Additions to long-lived assets					25,194	15,327	20,165
CANADA
Long-lived assets:
Long-lived assets		10,488	12,899	10,488	10,488	12,899	14,429
Additions to long-lived assets					506	555	2,280
Net sales		220,020	206,620	867,864	867,864	851,995	757,853
Long-lived assets		$ 162,568	$ 158,640	$ 162,568	162,568	158,640	150,173
Additions to long-lived assets					$ 44,019	$ 32,281	$ 34,953

[1] Sales by country represent sale to customer or distributor locations.