Guarantor Financial Information (Condensed Consolidated Statements of Operations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 30, 2013	Mar. 31, 2012
Net sales	$ 445,422	$ 387,108
Costs and expenses:
Cost of sales and operating expenses	322,686	276,469
Selling, general and administrative expenses	42,293	37,369
Depreciation and amortization	21,867	20,760
Total costs and expenses	386,846	334,598
Operating income	58,576	52,510
Interest expense	(5,625)	(6,925)
Other income/(expense), net	1,067	(608)
Equity in net loss of unconsolidated subsidiary	(1,195)	(236)
Earnings in investments in subsidiaries	0	0
Income before income taxes	52,823	44,741
Income taxes	20,418	16,170
Net income	32,405	28,571
Issuer [Member]
Net sales	161,872	152,988
Costs and expenses:
Cost of sales and operating expenses	124,104	121,097
Selling, general and administrative expenses	22,567	20,785
Depreciation and amortization	6,138	6,296
Total costs and expenses	152,809	148,178
Operating income	9,063	4,810
Interest expense	(5,621)	(6,925)
Other income/(expense), net	938	(642)
Equity in net loss of unconsolidated subsidiary	0	0
Earnings in investments in subsidiaries	29,718	30,332
Income before income taxes	34,098	27,575
Income taxes	1,693	(996)
Net income	32,405	28,571
Guarantors [Member]
Net sales	319,411	273,509
Costs and expenses:
Cost of sales and operating expenses	234,521	194,813
Selling, general and administrative expenses	19,686	16,545
Depreciation and amortization	15,723	14,458
Total costs and expenses	269,930	225,816
Operating income	49,481	47,693
Interest expense	(4)	0
Other income/(expense), net	135	27
Equity in net loss of unconsolidated subsidiary	0	0
Earnings in investments in subsidiaries	0	0
Income before income taxes	49,612	47,720
Income taxes	19,177	17,246
Net income	30,435	30,474
Non-guarantors [Member]
Net sales	4,134	2,554
Costs and expenses:
Cost of sales and operating expenses	4,056	2,502
Selling, general and administrative expenses	40	39
Depreciation and amortization	6	6
Total costs and expenses	4,102	2,547
Operating income	32	7
Interest expense	0	0
Other income/(expense), net	(6)	7
Equity in net loss of unconsolidated subsidiary	(1,195)	(236)
Earnings in investments in subsidiaries	0	0
Income before income taxes	(1,169)	(222)
Income taxes	(452)	(80)
Net income	(717)	(142)
Eliminations [Member]
Net sales	(39,995)	(41,943)
Costs and expenses:
Cost of sales and operating expenses	(39,995)	(41,943)
Selling, general and administrative expenses	0	0
Depreciation and amortization	0	0
Total costs and expenses	(39,995)	(41,943)
Operating income	0	0
Interest expense	0	0
Other income/(expense), net	0	0
Equity in net loss of unconsolidated subsidiary	0	0
Earnings in investments in subsidiaries	(29,718)	(30,332)
Income before income taxes	(29,718)	(30,332)
Income taxes	0	0
Net income	$ (29,718)	$ (30,332)