Note 10 - Business Unit Segment Information - Long-lived Assets by Geographical Area (Details) - USD ($) $ in Thousands		6 Months Ended
		Jun. 27, 2015	Jun. 28, 2014	Dec. 27, 2014
UNITED STATES
Long-lived assets	[1]	$ 34,129		$ 34,179
Additions to long-lived assets		6,615	$ 3,309
MEXICO
Long-lived assets	[1]	46,052		47,936
Additions to long-lived assets		4,190	4,694
CHINA
Long-lived assets	[1]	40,416		40,981
Additions to long-lived assets		4,080	2,506
Other Countries [Member]
Long-lived assets	[1]	45,782		35,544
Additions to long-lived assets		11,503	2,623
Long-lived assets	[1]	166,379		$ 158,640
Additions to long-lived assets		$ 26,388	$ 13,132

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