Consolidated Statements Of Comprehensive Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jul. 01, 2012	Jul. 03, 2011	Jul. 01, 2012	Jul. 03, 2011
Consolidated Statements Of Earnings [Abstract]
Net sales	$ 117,114	$ 98,268	$ 213,887	$ 207,154
Cost of sales	97,520	77,603	173,941	164,535
Gross profit	19,594	20,665	39,946	42,619
Selling and general expenses	6,039	4,294	11,753	9,109
Operating profit	13,555	16,371	28,193	33,510
Other income	8	485	121	1,025
Earnings before provision for income taxes	13,563	16,856	28,314	34,535
Income tax provision	4,860	6,039	10,267	12,355
Net earnings	8,703	10,817	18,047	22,180
Weighted average shares outstanding:
Basic	6,882	6,871	6,879	6,868
Diluted	6,884	6,872	6,881	6,869
Net earnings per share:
Basic	$ 1.26	$ 1.57	$ 2.62	$ 3.23
Diluted	$ 1.26	$ 1.57	$ 2.62	$ 3.23
Other comprehensive income (loss), net of tax:
Unrealized gain (loss) on available-for-sale securities	(18)	11	(14)	(1)
Comprehensive income	$ 8,685	$ 10,828	$ 18,033	$ 22,179
Cash dividends declared and paid per common share	$ 0.00	$ 0.00	$ 6.00	$ 8.25