Guarantees (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
Jun. 15, 2013	Dec. 29, 2012
Guarantees [Text Block]
Guarantor Obligations, Caption for Recorded Liabilities	lease obligations
Guarantor Obligations, Current Carrying Value	$ 1.2	$ 1.4
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 7.3	$ 8.3

Name:	nafc_GuaranteesTextBlockAbstract
Namespace Prefix:	nafc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Discloses the financial statement line item in which the aggregate carrying amount of the liability for recorded guarantees is included.

+ References

No definition available.

+ Details

Name:	us-gaap_GuaranteeObligationsCaptionForRecordedLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 460

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

+ Details

Name:	us-gaap_GuaranteeObligationsCurrentCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 460

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph (b)(1)

-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

+ Details

Name:	us-gaap_GuaranteeObligationsMaximumExposure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant