Condensed Consolidating Financial Statements (Statements of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2015	Sep. 30, 2014	Sep. 29, 2015	Sep. 30, 2014
Condensed Consolidating Statements of Income
Total sales	$ 300,652	$ 299,599	$ 916,096	$ 881,758
Total costs and expenses	295,929	292,626	885,835	854,085
Operating income	4,723	6,973	30,261	27,673
Interest expense	10,240	10,344	31,197	30,548
Equity in net income of subsidiary	0	0	0	0
Loss before income taxes	(5,517)	(3,371)	(936)	(2,875)
Income tax benefit	(3,401)	(3,533)	(3,867)	(4,619)
Net (loss) income	(2,116)	162	2,931	1,744
Parent Guarantor: Holdings
Condensed Consolidating Statements of Income
Total sales	0	0	0	0
Total costs and expenses	0	0	0	0
Operating income	0	0	0	0
Interest expense	0	0	0	0
Equity in net income of subsidiary	(2,116)	162	2,931	1,744
Loss before income taxes	(2,116)	162	2,931	1,744
Income tax benefit	0	0	0	0
Net (loss) income	(2,116)	162	2,931	1,744
Subsidiary Issuer: NPC
Condensed Consolidating Statements of Income
Total sales	249,891	251,827	764,369	771,042
Total costs and expenses	245,946	245,803	739,355	745,553
Operating income	3,945	6,024	25,014	25,489
Interest expense	10,240	10,344	31,197	30,548
Equity in net income of subsidiary	(1,440)	303	3,483	1,091
Loss before income taxes	(7,735)	(4,017)	(2,700)	(3,968)
Income tax benefit	(5,619)	(4,179)	(5,631)	(5,712)
Net (loss) income	(2,116)	162	2,931	1,744
Subsidiary Co-Issuer: NPCQB
Condensed Consolidating Statements of Income
Total sales	50,761	47,772	151,727	110,716
Total costs and expenses	49,983	46,823	146,480	108,532
Operating income	778	949	5,247	2,184
Interest expense	0	0	0	0
Equity in net income of subsidiary	0	0	0	0
Loss before income taxes	778	949	5,247	2,184
Income tax benefit	2,218	646	1,764	1,093
Net (loss) income	(1,440)	303	3,483	1,091
Subsidiary Co-Issuer: NPC Op Co B
Condensed Consolidating Statements of Income
Total sales	0	0	0	0
Total costs and expenses	0	0	0	0
Operating income	0	0	0	0
Interest expense	0	0	0	0
Equity in net income of subsidiary	0	0	0	0
Loss before income taxes	0	0	0	0
Income tax benefit	0	0	0	0
Net (loss) income	0	0	0	0
Eliminations
Condensed Consolidating Statements of Income
Total sales	0	0	0	0
Total costs and expenses	0	0	0	0
Operating income	0	0	0	0
Interest expense	0	0	0	0
Equity in net income of subsidiary	3,556	(465)	(6,414)	(2,835)
Loss before income taxes	3,556	(465)	(6,414)	(2,835)
Income tax benefit	0	0	0	0
Net (loss) income	$ 3,556	$ (465)	$ (6,414)	$ (2,835)