Note 10 - Business Unit Segment Information (Details) - Net Sales by Geographic Area (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 28, 2015		Mar. 29, 2014
Note 10 - Business Unit Segment Information (Details) - Net Sales by Geographic Area [Line Items]
Net sales	$ 210,313	[1]	$ 206,859	[1]
UNITED STATES
Note 10 - Business Unit Segment Information (Details) - Net Sales by Geographic Area [Line Items]
Net sales	83,373	[1]	71,874	[1]
CANADA
Note 10 - Business Unit Segment Information (Details) - Net Sales by Geographic Area [Line Items]
Net sales	44,429	[1]	37,213	[1]
Other Countries [Member]
Note 10 - Business Unit Segment Information (Details) - Net Sales by Geographic Area [Line Items]
Net sales	$ 82,511	[1]	$ 97,772	[1]

[1] Sales by country represent sales to customer or distributor locations.