Note 10 - Business Unit Segment Information - Long-lived Assets by Geographical Area (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 26, 2015	Sep. 27, 2014	Dec. 27, 2014
UNITED STATES
Long-lived assets	[1]	$ 27,250		$ 34,179
Additions to long-lived assets		8,367	$ 5,215
MEXICO
Long-lived assets	[1]	13,613		47,936
Additions to long-lived assets		6,518	5,784
CHINA
Long-lived assets	[1]	37,900		40,981
Additions to long-lived assets		5,159	3,461
Other Countries [Member]
Long-lived assets	[1]	84,002		35,544
Additions to long-lived assets		15,082	4,962
Long-lived assets	[1]	162,765		$ 158,640
Additions to long-lived assets		$ 35,126	$ 19,422

[1] Long-lived assets consists of net property, plant and equipment.