Note 10 - Segment Information - Revenues and Long-lived Assets by Geographical Area (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2016	Dec. 31, 2016
Net sales		$ 317,889	$ 280,331	$ 916,685	$ 771,641
Long-lived assets		244,874		244,874			$ 217,175
Additions to long-lived assets				48,470		$ 34,501
UNITED STATES
Net sales		103,233	92,475	290,538	270,659
Long-lived assets		23,922		23,922			23,731
Additions to long-lived assets				2,752		4,485
CHINA
Net sales	[1]	82,986	70,215	240,731	181,134
Long-lived assets	[1]	80,616		80,616			65,345
Additions to long-lived assets	[1]			22,165		8,272
Other Countries [Member]
Net sales		131,670	$ 117,641	385,416	$ 319,848
Long-lived assets		47,912		47,912			42,492
Additions to long-lived assets				6,494		5,378
MEXICO
Long-lived assets		61,664		61,664			52,262
Additions to long-lived assets				15,041		12,312
PHILIPPINES
Long-lived assets		$ 30,760		30,760			$ 33,345
Additions to long-lived assets				$ 2,018		$ 4,054

[1] Included in China are net sales in China and Hong Kong.