Pension, Postretirement and Postemployment Benefits, Beginning of Fair Value Measurement (Details) (USD $) In Thousands, unless otherwise specified	Dec. 30, 2012	Dec. 25, 2011
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	$ 273,600	$ 265,000
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	19,400	31,400
Significant Other Observable Inputs (Level 2) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	195,200	179,500
Significant Unobservable Inputs (Level 3) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	59,000	54,100
Equity - Large Cap [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	8,000	12,500
Equity - Large Cap [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	8,000	12,500
Equity - Large Cap [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	0	0
Equity - Large Cap [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	0	0
Equity - Small Cap [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	11,400	18,900
Equity - Small Cap [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	11,400	18,900
Equity - Small Cap [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	0	0
Equity - Small Cap [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	0	0
Equity - International [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	33,600	29,200
Equity - International [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	0	0
Equity - International [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	33,600	29,200
Equity - International [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	0	0
Equity - Other [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	56,600	47,400
Equity - Other [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	0	0
Equity - Other [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	0	0
Equity - Other [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	56,600	47,400
Fixed Income Funds [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	110,600	120,900
Fixed Income Funds [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	0	0
Fixed Income Funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	108,200	114,200
Fixed Income Funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	2,400	6,700
Total Return Fund [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	31,800	28,900
Total Return Fund [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	0	0
Total Return Fund [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	31,800	28,900
Total Return Fund [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	0	0
Cash Equivalents [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	21,600	7,200
Cash Equivalents [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	0	0
Cash Equivalents [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	21,600	7,200
Cash Equivalents [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	$ 0	$ 0