Note 13 - Segment Information (Details) - Information about net income, segment assets, and certain other items (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jul. 01, 2012	Jun. 30, 2013	Jul. 01, 2012
Segment Reporting Information [Line Items]
Net outside sales	$ 159,576	$ 115,605	$ 301,696	$ 218,293
Operating income	15,708	10,060	29,351	19,488
Manufacturing [Member]
Segment Reporting Information [Line Items]
Net outside sales	125,027	88,549	236,490	168,236
Intersegment sales	5,282	4,146	10,221	8,137
Operating income	13,355	8,684	25,079	16,777
Distribution [Member]
Segment Reporting Information [Line Items]
Net outside sales	34,549	27,056	65,206	50,057
Intersegment sales	751	501	1,612	896
Operating income	2,353	1,376	4,272	2,711
Intersegment Revenue [Member]
Segment Reporting Information [Line Items]
Intersegment sales	$ 6,033	$ 4,647	$ 11,833	$ 9,033