Condensed Consolidating Financial Statements (Cash Flows) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Apr. 01, 2014
Operating activities
Net cash flows provided by operating activities	$ 24,450	$ 24,773
Investing activities
Capital expenditures	(11,018)	(19,246)
Investment in NPCQB	0	0
Proceeds from sale or disposition of assets	296	324
Net cash used in investing activities	(10,722)	(18,922)
Financing activities
Investment from parent	0
Accrued purchase price paid to sellers	0	(10,875)
Net payments on debt	(2,079)	(7,625)
Distribution to parent		0
Net cash used in financing activities	(2,079)	(18,500)
Net change in cash and cash equivalents	11,649	(12,649)
Beginning cash and cash equivalents	12,063	20,035
Ending cash and cash equivalents	23,712	7,386
Parent Guarantor: Holdings
Operating activities
Net cash flows provided by operating activities	0	0
Investing activities
Capital expenditures	0	0
Investment in NPCQB	0	0
Proceeds from sale or disposition of assets	0	0
Net cash used in investing activities	0	0
Financing activities
Investment from parent	0
Accrued purchase price paid to sellers		0
Net payments on debt	0	0
Distribution to parent		0
Net cash used in financing activities	0	0
Net change in cash and cash equivalents	0	0
Beginning cash and cash equivalents	0	0
Ending cash and cash equivalents	0	0
Subsidiary Issuer: NPC
Operating activities
Net cash flows provided by operating activities	20,689	20,390
Investing activities
Capital expenditures	(7,127)	(18,191)
Investment in NPCQB	(110)	3,387
Proceeds from sale or disposition of assets	258	324
Net cash used in investing activities	(6,979)	(14,480)
Financing activities
Investment from parent	0
Accrued purchase price paid to sellers		(10,875)
Net payments on debt	(2,079)	(7,625)
Distribution to parent		0
Net cash used in financing activities	(2,079)	(18,500)
Net change in cash and cash equivalents	11,631	(12,590)
Beginning cash and cash equivalents	11,278	19,170
Ending cash and cash equivalents	22,909	6,580
Subsidiary Co-Issuer: NPCQB
Operating activities
Net cash flows provided by operating activities	3,761	4,383
Investing activities
Capital expenditures	(3,891)	(1,055)
Investment in NPCQB	0	0
Proceeds from sale or disposition of assets	38	0
Net cash used in investing activities	(3,853)	(1,055)
Financing activities
Investment from parent	110
Accrued purchase price paid to sellers		0
Net payments on debt	0
Distribution to parent		(3,387)
Net cash used in financing activities	110	(3,387)
Net change in cash and cash equivalents	18	(59)
Beginning cash and cash equivalents	785	865
Ending cash and cash equivalents	803	806
Subsidiary Co-Issuer: NPC Op Co B
Operating activities
Net cash flows provided by operating activities	0	0
Investing activities
Capital expenditures	0	0
Investment in NPCQB	0	0
Proceeds from sale or disposition of assets	0	0
Net cash used in investing activities	0	0
Financing activities
Investment from parent	0
Accrued purchase price paid to sellers		0
Net payments on debt	0	0
Distribution to parent		0
Net cash used in financing activities	0	0
Net change in cash and cash equivalents	0	0
Beginning cash and cash equivalents	0	0
Ending cash and cash equivalents	0	0
Eliminations
Operating activities
Net cash flows provided by operating activities	0	0
Investing activities
Capital expenditures	0	0
Investment in NPCQB	110	(3,387)
Proceeds from sale or disposition of assets	0	0
Net cash used in investing activities	110	(3,387)
Financing activities
Investment from parent	(110)
Accrued purchase price paid to sellers		0
Net payments on debt	0
Distribution to parent		3,387
Net cash used in financing activities	(110)	3,387
Net change in cash and cash equivalents	0	0
Beginning cash and cash equivalents	0	0
Ending cash and cash equivalents	$ 0	$ 0