This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value on a recurring basis by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

No definition available.

+ Details

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

- Details

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

- Definition

This element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity).

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-Subparagraph c(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncome
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Purchases that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)

-URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

This element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to assets measured at fair value on a recurring basis using unobservable inputs (Level 3).

+ References

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesSalesIssuancesSettlements
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Pension Benefits - Reconciliation of Significant Observable Inputs (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended					12 Months Ended									12 Months Ended									12 Months Ended
	Dec. 25, 2011	Dec. 26, 2010	Dec. 25, 2011 Fair Value, Inputs, Level 3 [Member]	Dec. 26, 2010 Fair Value, Inputs, Level 3 [Member]	Dec. 27, 2009 Fair Value, Inputs, Level 3 [Member]	Dec. 25, 2011 Assets Still Held [Member]	Dec. 26, 2010 Assets Still Held [Member]	Dec. 25, 2011 Assets Sold [Member]	Dec. 26, 2010 Assets Sold [Member]	Dec. 25, 2011 Real Estate Funds [Member]	Dec. 26, 2010 Real Estate Funds [Member]	Dec. 25, 2011 Real Estate Funds [Member] Fair Value, Inputs, Level 3 [Member]	Dec. 26, 2010 Real Estate Funds [Member] Fair Value, Inputs, Level 3 [Member]	Dec. 27, 2009 Real Estate Funds [Member] Fair Value, Inputs, Level 3 [Member]	Dec. 25, 2011 Real Estate Funds [Member] Assets Still Held [Member]	Dec. 26, 2010 Real Estate Funds [Member] Assets Still Held [Member]	Dec. 25, 2011 Real Estate Funds [Member] Assets Sold [Member]	Dec. 26, 2010 Real Estate Funds [Member] Assets Sold [Member]	Dec. 25, 2011 Private Equity Funds [Member]	Dec. 26, 2010 Private Equity Funds [Member]	Dec. 25, 2011 Private Equity Funds [Member] Fair Value, Inputs, Level 3 [Member]	Dec. 26, 2010 Private Equity Funds [Member] Fair Value, Inputs, Level 3 [Member]	Dec. 27, 2009 Private Equity Funds [Member] Fair Value, Inputs, Level 3 [Member]	Dec. 25, 2011 Private Equity Funds [Member] Assets Still Held [Member]	Dec. 26, 2010 Private Equity Funds [Member] Assets Still Held [Member]	Dec. 25, 2011 Private Equity Funds [Member] Assets Sold [Member]	Dec. 26, 2010 Private Equity Funds [Member] Assets Sold [Member]
Pension Benefits
Assets, fair value disclosure, recurring	$ 1,459,372	$ 1,376,488	$ 37,393	$ 68,658	$ 54,502						$ 37,471	$ 0	$ 37,471	$ 33,938					$ 37,393	$ 31,187	$ 37,393	$ 31,187	$ 20,564
Actual gain on plan assets still held and sold during the period						4,021	8,036	541	0						0	3,533	541	0						4,021	4,503	0	0
Capital contribution	5,196	6,120								0	0								5,196	6,120
Sales of assets	$ (41,023)	$ 0								$ (38,012)	$ 0								$ (3,011)	$ 0