Consolidated Statements Of Comprehensive Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 29, 2013	Sep. 30, 2012	Sep. 29, 2013	Sep. 30, 2012
Consolidated Statements Of Comprehensive Income [Abstract]
Net sales	$ 100,612	$ 116,813	$ 285,198	$ 330,700
Cost of sales	80,962	93,906	230,928	267,847
Gross profit	19,650	22,907	54,270	62,853
Selling and general expenses	5,794	8,058	17,237	20,188
Operating profit	13,856	14,849	37,033	42,665
Other income	153	231	508	729
Earnings before provision for income taxes	14,009	15,080	37,541	43,394
Income tax provision	4,994	5,679	13,371	15,946
Net earnings	9,015	9,401	24,170	27,448
Weighted average common shares outstanding:
Basic and diluted	6,907	6,891	6,905	6,888
Net earnings per share:
Basic and diluted	$ 1.31	$ 1.36	$ 3.50	$ 3.98
Other comprehensive loss, net of tax:
Unrealized loss on available-for-sale securities	7	1	27	15
Comprehensive income	$ 9,008	$ 9,400	$ 24,143	$ 27,433
Cash dividends declared and paid per common share	$ 0.00	$ 0.00	$ 0.00	$ 6.00