Supplemental Quarterly Financial Data (Unaudited) - Prior Period Statement of Income Adjustments (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								6 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2014	Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Dec. 31, 2013	Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Jun. 28, 2014	Jun. 29, 2013	Sep. 27, 2014	Sep. 28, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net Income
Net Revenues	$ 187,612	$ 188,164	$ 186,516	$ 179,753	$ 187,975	$ 181,288	$ 191,472	$ 175,915	$ 366,269	$ 367,387	$ 554,433	$ 548,675	$ 742,045	$ 736,650	$ 747,037
Gross Profit	33,627	33,112	37,678	35,915	19,565	33,739	37,574	33,274	73,593	70,848	106,705	104,587	140,332	124,152	143,977
Income (Loss) Before Taxes	4,034	4,687	9,816	7,703	(7,359)	5,985	7,859	2,900	17,519	10,759	22,206	16,744	26,240	9,385	24,124
Income Tax Expense (Benefit)	(1,122)	1,754	3,197	2,544	(2,115)	(1,000)	2,193	(1,071)	5,741	1,122	7,495	122	6,373	(1,993)	6,501
Net Income (Loss)	5,156	2,933	6,619	5,159	(5,244)	6,985	5,666	3,971	11,778	9,637	14,711	16,622	19,867	11,378	17,623
Earnings (Loss) Per Share
Basic (in dollars per share)	$ 0.47	$ 0.27	$ 0.61	$ 0.48	$ (0.49)	$ 0.65	$ 0.53	$ 0.37	$ 1.08	$ 0.91	$ 1.35	$ 1.56	$ 1.82	$ 1.06	$ 1.67
Diluted (in dollars per share)	$ 0.46	$ 0.26	$ 0.60	$ 0.46	$ (0.49)	$ 0.64	$ 0.53	$ 0.37	$ 1.06	$ 0.90	$ 1.31	$ 1.54	$ 1.79	$ 1.05	$ 1.66
As Reported
Net Income
Net Revenues		188,164	186,516	179,753		181,288	191,472	175,915	366,269	367,387	554,433	548,675		736,650	747,037
Gross Profit		33,394	37,443	35,070		32,304	37,316	32,853	72,513	70,169	105,907	102,473		122,417	141,452
Income (Loss) Before Taxes		4,969	9,581	6,858		4,550	7,601	2,479	16,439	10,080	21,408	14,630		7,650	22,015
Income Tax Expense (Benefit)		2,347	3,109	2,229		(86)	2,097	(1,228)	5,338	869	7,685	783		(1,693)	5,578
Net Income (Loss)		$ 2,622	$ 6,472	$ 4,629		$ 4,636	$ 5,504	$ 3,707	$ 11,101	$ 9,211	$ 13,723	$ 13,847		$ 9,343	$ 16,437
Earnings (Loss) Per Share
Basic (in dollars per share)		$ 0.24	$ 0.60	$ 0.43		$ 0.43	$ 0.52	$ 0.35	$ 1.02	$ 0.87	$ 1.26	$ 1.30		$ 0.87	$ 1.55
Diluted (in dollars per share)		$ 0.24	$ 0.59	$ 0.42		$ 0.42	$ 0.51	$ 0.35	$ 1.00	$ 0.86	$ 1.23	$ 1.28		$ 0.86	$ 1.55