Condensed Consolidating Financial Statements (Details Textual)	9 Months Ended	12 Months Ended
Sep. 24, 2013	Dec. 31, 2013
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Ownership percentage held by holding company		100.00%
Ownership Percentage of co Issuer held by company	100.00%

Ownership percentage of co issuer held by company.

No definition available.

Name:	npci_OwnershipPercentageOfCoIssuerHeldByCompany
Namespace Prefix:	npci_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration