Supplementary Quarterly Financial Data (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 29, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Oct. 01, 2011	Jul. 02, 2011	Apr. 02, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Supplementary Information [Line Items]
Net Sales	$ 193,892	$ 184,097	$ 184,705	$ 184,343	$ 188,238	$ 185,080	$ 108,043	$ 99,553	$ 747,037	$ 580,914	$ 408,406
Gross Profit	35,450	35,580	35,951	34,471	32,338	34,186	21,004	18,408
Income (Loss) Before Taxes	6,618	5,999	5,778	3,620	(53,576)	1,376	(4,124)	3,999	22,015	(52,325)	24,663
Income Tax Expense (Benefit)	3,183	894	271	1,230	(5,082)	415	(1,151)	1,076	5,578	(4,742)	4,855
Net Income (Loss)	$ 3,435	$ 5,105	$ 5,507	$ 2,390	$ (48,494)	$ 961	$ (2,973)	$ 2,923	$ 16,437	$ (47,583)	$ 19,808
Earnings Per Share
Basic earnings (loss) per share	$ 0.32	$ 0.48	$ 0.52	$ 0.23	$ (4.60)	$ 0.09	$ (0.28)	$ 0.28	$ 1.55	$ (4.52)	$ 1.89
Diluted earnings (loss) per share	$ 0.32	$ 0.48	$ 0.52	$ 0.23	$ (4.60)	$ 0.09	$ (0.28)	$ 0.27	$ 1.55	$ (4.52)	$ 1.87