Note 10 - Business Unit Segment Information (Details) - Long-lived Assets by Geographical Area (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 28, 2015	Mar. 29, 2014	Dec. 27, 2014
Note 10 - Business Unit Segment Information (Details) - Long-lived Assets by Geographical Area [Line Items]
Long-lived assets	$ 160,872		$ 158,640
Additions to long-lived assets	12,279	6,423
UNITED STATES
Note 10 - Business Unit Segment Information (Details) - Long-lived Assets by Geographical Area [Line Items]
Long-lived assets	35,641		34,179
Additions to long-lived assets	3,187	1,625
CHINA
Note 10 - Business Unit Segment Information (Details) - Long-lived Assets by Geographical Area [Line Items]
Long-lived assets	39,321		40,981
Additions to long-lived assets	667	685
CANADA
Note 10 - Business Unit Segment Information (Details) - Long-lived Assets by Geographical Area [Line Items]
Long-lived assets	12,160		12,899
Additions to long-lived assets	538	145
Other Countries [Member]
Note 10 - Business Unit Segment Information (Details) - Long-lived Assets by Geographical Area [Line Items]
Long-lived assets	73,750		70,581
Additions to long-lived assets	$ 7,887	$ 3,968