Fair value of the assets less the liabilities of a derivative or group of derivatives.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 10

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13433-108611

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 45

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 15

-URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13495-108611

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 45

-Paragraph 6

-URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41271-113958

Name:	us-gaap_DerivativeFairValueOfDerivativeNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Derivative Financial Instruments (Balance Sheet Location) (Details) (USD $)			6 Months Ended
	Jun. 29, 2013	Dec. 29, 2012	Jun. 29, 2013 Diesel Fuel Swap [Member]	Jun. 29, 2013 Diesel Fuel Swap [Member] Accounts Payable and Accrued Expenses [Member]	Dec. 29, 2012 Diesel Fuel Swap [Member] Accounts Payable and Accrued Expenses [Member]	Jun. 29, 2013 Diesel Fuel Swap [Member] Prepaid Expenses and Other Current Assets [Member]	Dec. 29, 2012 Diesel Fuel Swap [Member] Prepaid Expenses and Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Expected hedging percentage of diesel fuel requirements for next twelve months			50.00%
Deferred net losses, net of tax			$ 0
Derivative, Fair Value, Net [Abstract]
Derivative, fair value, net	$ 61,000	$ (119,000)		$ 0	$ (242,000)	$ 61,000	$ 123,000