Condensed Consolidating Financial Statements (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 24, 2013	Sep. 25, 2012	Sep. 24, 2013	Sep. 25, 2012
Condensed Consolidating Statements of Income
Total sales	$ 260,805	$ 256,233	$ 801,732	$ 790,208
Total costs and expenses	248,522	243,565	742,684	731,942
Operating income	12,283	12,668	59,048	58,266
Interest expense	10,243	11,416	30,720	35,797
Loss on debt extinguishment			0	5,144
Equity in net income of subsidiary		0	0	0
Income before income taxes	2,040	1,252	28,328	17,325
Income tax benefit	(522)	(1,126)	4,434	2,953
Net income	2,562	2,378	23,894	14,372
Parent Guarantor: Holdings [Member]
Condensed Consolidating Statements of Income
Total sales			0	0
Total costs and expenses			0	0
Operating income		0	0	0
Interest expense			0	0
Loss on debt extinguishment				0
Equity in net income of subsidiary	2,562	2,378	23,894	14,372
Income before income taxes	2,562	2,378	23,894	14,372
Income tax benefit	0	0	0	0
Net income	2,562	2,378	23,894	14,372
Subsidiary Issuer: NPC [Member]
Condensed Consolidating Statements of Income
Total sales	252,798	256,233	793,725	790,208
Total costs and expenses	240,103	243,565	734,265	731,942
Operating income	12,695	12,668	59,460	58,266
Interest expense	10,243	11,416	30,720	35,797
Loss on debt extinguishment				5,144
Equity in net income of subsidiary			0	0
Income before income taxes	2,452	1,252	28,740	17,325
Income tax benefit	(427)	(1,126)	4,529	2,953
Net income	2,879	2,378	24,211	14,372
Subsidiary Co-Issuer: NPC Op Co A [Member]
Condensed Consolidating Statements of Income
Total sales	8,007		8,007	0
Total costs and expenses	8,419		8,419	0
Operating income	(412)	0	(412)	0
Interest expense			0	0
Loss on debt extinguishment				0
Equity in net income of subsidiary			0	0
Income before income taxes	(412)	0	(412)	0
Income tax benefit	(95)		(95)	0
Net income	(317)	0	(317)	0
Subsidiary Co-Issuer: NPC Op Co B [Member]
Condensed Consolidating Statements of Income
Total sales			0	0
Total costs and expenses			0	0
Operating income		0	0	0
Interest expense			0	0
Loss on debt extinguishment				0
Equity in net income of subsidiary			0	0
Income before income taxes		0	0	0
Income tax benefit			0	0
Net income		0	0	0
Eliminations [Member]
Condensed Consolidating Statements of Income
Total sales			0	0
Total costs and expenses			0	0
Operating income		0	0	0
Interest expense			0	0
Loss on debt extinguishment				0
Equity in net income of subsidiary	(2,562)	(2,378)	(23,894)	(14,372)
Income before income taxes	(2,562)	(2,378)	(23,894)	(14,372)
Income tax benefit	0		0	0
Net income	$ (2,562)	$ (2,378)	$ (23,894)	$ (14,372)