Note 10 - Segment Information - Revenues and Long-lived Assets by Geographical Area (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 01, 2017	Jul. 02, 2016	Jul. 01, 2017	Jul. 02, 2016	Dec. 31, 2016
Net sales	$ 313,355	$ 271,912	$ 598,797	$ 491,310
Long-lived assets	232,539		232,539		$ 217,175
Additions to long-lived assets			28,878	20,217
UNITED STATES
Net sales	100,648	93,036	187,306	178,184
Long-lived assets	23,415		23,415		23,731
Additions to long-lived assets			1,149	2,783
CHINA
Net sales	83,055	62,411	157,745	110,919
Long-lived assets	70,671		70,671		65,345
Additions to long-lived assets			10,149	3,847
Other Countries [Member]
Net sales	129,652	$ 116,465	253,746	202,207
Long-lived assets	46,708		46,708		42,492
Additions to long-lived assets			5,310	2,498
MEXICO
Long-lived assets	60,172		60,172		52,262
Additions to long-lived assets			10,925	8,164
PHILIPPINES
Long-lived assets	$ 31,573		31,573		$ 33,345
Additions to long-lived assets			$ 1,345	$ 2,925