Pension, Postretirement and Postemployment Benefits, Beginning of Fair Value Measurement (Details) (USD $) In Thousands, unless otherwise specified	Dec. 25, 2011	Dec. 26, 2010
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	$ 265,000	$ 270,100
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	31,400	46,000
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	179,500	170,900
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	54,100	53,200
Equity - Large Cap [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	12,500	17,200
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	12,500	17,200
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	18,900	28,800
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	18,900	28,800
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	29,200	34,800
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	29,200	34,800
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	47,400	47,900
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	47,400	47,900
Fixed Income Funds [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	120,900	102,400
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	114,200	97,100
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	6,700	5,300
Total Return Fund [Member]
Fair values of plan assets by asset class and fair value hierarchy level [Abstract]
Fair Value of Plan Asset	28,900	33,500
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	28,900	33,500
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	7,200	5,500
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	7,200	5,500
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