Consolidated Statements of Income (Unaudited) (USD $) In Thousands, except Per Share data	3 Months Ended		6 Months Ended
	Jul. 01, 2011	Jul. 02, 2010	Jul. 01, 2011	Jul. 02, 2010
Consolidated Statements of Income [Abstract]
Net sales	$ 424,710	$ 325,946	$ 799,515	$ 621,028
Cost of sales	362,039	270,093	681,043	515,861
Gross margin	62,671	55,853	118,472	105,167
Selling, general and administrative expense	34,048	30,611	65,691	60,950
Research and development expense	2,714	1,798	5,124	3,483
Other-net	5,064	2,946	8,735	7,031
Operating profit	20,845	20,498	38,922	33,703
Interest expense - net	613	691	1,198	1,310
Income before income taxes	20,232	19,807	37,724	32,393
Income tax expense	6,360	6,088	12,034	11,953
Net income	$ 13,872	$ 13,719	$ 25,690	$ 20,440
Net income per share of common stock - basic	$ 0.68	$ 0.68	$ 1.26	$ 1.01
Weighted-average number of common shares outstanding - basic	20,421	20,323	20,388	20,290
Net income per share of common stock - diluted	$ 0.67	$ 0.67	$ 1.23	$ 1.00
Weighted-average number of common shares outstanding - diluted	20,832	20,600	20,812	20,534