Pension Benefits - Fair Value of Plan Assets (Details) (USD $) | Dec. 29, 2013 | Dec. 30, 2012 | Dec. 25, 2011 |
In Thousands, unless otherwise specified |
Level 1 [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | $112,526 | | $280,762 | | ' |
Level 1 [Member] | U.S. Equity Securities [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 36,920 | | 193,489 | | ' |
Level 1 [Member] | International Equity Securities [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 75,606 | | 87,273 | | ' |
Level 1 [Member] | Common Collective Funds [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 0 | [1] | 0 | [1] | ' |
Level 1 [Member] | Corporate Bond Securities [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 0 | | 0 | | ' |
Level 1 [Member] | US Treasury and Government [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 0 | | 0 | | ' |
Level 1 [Member] | Insurance Contracts [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 0 | | 0 | | ' |
Level 1 [Member] | Municipal Bonds [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 0 | | 0 | | ' |
Level 1 [Member] | US Government Agencies Debt Securities [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 0 | [2] | 0 | [2] | ' |
Level 1 [Member] | Other Investments [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 0 | | 0 | | ' |
Level 1 [Member] | Cash and Cash Equivalents [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | ' | | 0 | | ' |
Level 1 [Member] | Private Equity Funds [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 0 | | 0 | | ' |
Level 1 [Member] | Hedge Funds [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 0 | | 0 | | ' |
Level 2 [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 1,514,703 | | 1,266,146 | | ' |
Level 2 [Member] | U.S. Equity Securities [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 0 | | 0 | | ' |
Level 2 [Member] | International Equity Securities [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 0 | | 0 | | ' |
Level 2 [Member] | Common Collective Funds [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 581,553 | [1] | 678,449 | [1] | ' |
Level 2 [Member] | Corporate Bond Securities [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 594,667 | | 383,483 | | ' |
Level 2 [Member] | US Treasury and Government [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 183,700 | | 91,122 | | ' |
Level 2 [Member] | Insurance Contracts [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 72,663 | | 44,511 | | ' |
Level 2 [Member] | Municipal Bonds [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 41,729 | | 22,192 | | ' |
Level 2 [Member] | US Government Agencies Debt Securities [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 4,738 | [2] | 19,115 | [2] | ' |
Level 2 [Member] | Other Investments [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 29,115 | | 10,847 | | ' |
Level 2 [Member] | Cash and Cash Equivalents [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 6,538 | | 16,427 | | ' |
Level 2 [Member] | Private Equity Funds [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 0 | | 0 | | ' |
Level 2 [Member] | Hedge Funds [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 0 | | 0 | | ' |
Level 3 [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 70,862 | | 62,381 | | 37,393 |
Level 3 [Member] | U.S. Equity Securities [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 0 | | 0 | | ' |
Level 3 [Member] | International Equity Securities [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 0 | | 0 | | ' |
Level 3 [Member] | Common Collective Funds [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 0 | [1] | 0 | [1] | ' |
Level 3 [Member] | Corporate Bond Securities [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 0 | | 0 | | ' |
Level 3 [Member] | US Treasury and Government [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 0 | | 0 | | ' |
Level 3 [Member] | Insurance Contracts [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 0 | | 0 | | ' |
Level 3 [Member] | Municipal Bonds [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 0 | | 0 | | ' |
Level 3 [Member] | US Government Agencies Debt Securities [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 0 | [2] | 0 | [2] | ' |
Level 3 [Member] | Other Investments [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 0 | | 0 | | ' |
Level 3 [Member] | Cash and Cash Equivalents [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 0 | | 0 | | ' |
Level 3 [Member] | Private Equity Funds [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 40,537 | | 36,011 | | 37,393 |
Level 3 [Member] | Hedge Funds [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 30,325 | | 26,370 | | ' |
Estimate of Fair Value, Fair Value Disclosure [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 1,698,091 | | 1,609,289 | | ' |
Fair value of plan assets | 1,698,091 | | 1,615,723 | | ' |
Estimate of Fair Value, Fair Value Disclosure [Member] | U.S. Equity Securities [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 36,920 | | 193,489 | | ' |
Estimate of Fair Value, Fair Value Disclosure [Member] | International Equity Securities [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 75,606 | | 87,273 | | ' |
Estimate of Fair Value, Fair Value Disclosure [Member] | Common Collective Funds [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 581,553 | [1] | 678,449 | [1] | ' |
Estimate of Fair Value, Fair Value Disclosure [Member] | Corporate Bond Securities [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 594,667 | | 383,483 | | ' |
Estimate of Fair Value, Fair Value Disclosure [Member] | US Treasury and Government [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 183,700 | | 91,122 | | ' |
Estimate of Fair Value, Fair Value Disclosure [Member] | Insurance Contracts [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 72,663 | | 44,511 | | ' |
Estimate of Fair Value, Fair Value Disclosure [Member] | Municipal Bonds [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 41,729 | | 22,192 | | ' |
Estimate of Fair Value, Fair Value Disclosure [Member] | US Government Agencies Debt Securities [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 4,738 | [2] | 19,115 | [2] | ' |
Estimate of Fair Value, Fair Value Disclosure [Member] | Other Investments [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 29,115 | | 10,847 | | ' |
Estimate of Fair Value, Fair Value Disclosure [Member] | Cash and Cash Equivalents [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 6,538 | | 16,427 | | ' |
Estimate of Fair Value, Fair Value Disclosure [Member] | Private Equity Funds [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 40,537 | | 36,011 | | ' |
Estimate of Fair Value, Fair Value Disclosure [Member] | Hedge Funds [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | 30,325 | | 26,370 | | ' |
Estimate of Fair Value, Fair Value Disclosure [Member] | Other Assets [Member] | ' | | ' | | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | | ' | | ' |
Assets, fair value disclosure, recurring | $0 | | $6,434 | | ' |
|
[1] | The underlying assets of the common/collective funds are primarily comprised of equity and fixed income securities. The fair value in the above table represents our ownership share of the net asset value of the underlying funds. |
[2] | Represents investments that are not backed by the full faith and credit of the United States government. |