Note 12 - Segment Information - Revenues and Long-lived Assets by Geographical Area (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017	Dec. 30, 2017
Net sales		$ 459,183	$ 313,355	$ 876,996	$ 598,797
Long-lived assets		338,755		338,755		$ 250,577
Additions to long-lived assets				40,315	28,878
UNITED STATES
Net sales		137,236	100,648	261,112	187,306
Long-lived assets		59,097		59,097		23,490
Additions to long-lived assets				4,234	1,149
CHINA
Net sales	[1]	127,776	86,891	234,284	165,111
Long-lived assets		92,832		92,832		86,866
Additions to long-lived assets	[2]			14,711	10,200
MEXICO
Long-lived assets		66,063		66,063		62,510
Additions to long-lived assets				8,874	10,925
GERMANY
Long-lived assets		35,013		35,013		1,082
Additions to long-lived assets				5,182
Other Countries [Member]
Net sales	[3]	194,171	$ 125,816	381,600	246,380
Long-lived assets		54,269		54,269		45,500
Additions to long-lived assets				3,073	5,259
PHILIPPINES
Long-lived assets		$ 31,481		31,481		$ 31,129
Additions to long-lived assets				$ 4,241	$ 1,345

[1] Includes mainland China, Taiwan, and Hong Kong.

[2] Includes mainland China, Taiwan, and Hong Kong.

[3] Each country included in Other countries are less than 10% of net sales.