Pension Benefits Pension Benefits - Changes in Benefit Obligation and Plan Assets (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 25, 2011	Dec. 26, 2010	Dec. 27, 2009
Pension Benefits
Benefit obligation	$ 2,263,562	$ 2,077,368	$ 1,901,846
Service cost	13,739	13,941
Interest cost	113,284	116,125
Plan participants’ contributions	34	32
Actuarial loss	165,807	157,092
Curtailments	0	(1,083)
Benefits paid	(106,637)	(110,262)
Effects of change in currency conversion	(33)	(323)
Fair value of plan assets	1,464,729	1,381,811	1,150,915
Actual return on plan assets	21,712	147,837
Employer contributions	167,809	193,289
Current liabilities	(18,784)	(16,436)
Noncurrent liabilities	(780,049)	(679,121)
Net amount recognized	(798,833)	(695,557)
Actuarial loss	1,003,344	776,432
Prior service cost	1,959	2,762
Total amount recognized in accumulated other comprehensive loss	1,005,303	779,194
Accumulated benefit obligation	2,220,000	2,040,000
Qualified Plans [Member]
Pension Benefits
Benefit obligation	1,986,502	1,823,625	1,671,244
Service cost	12,079	12,045	28,266
Interest cost	99,991	102,523	102,757
Plan participants’ contributions	34	32
Actuarial loss	140,186	131,759
Curtailments	0	(1,083)
Benefits paid	(89,413)	(92,895)
Effects of change in currency conversion	0	0
Fair value of plan assets	1,464,729	1,381,811	1,150,915
Actual return on plan assets	21,712	147,837
Employer contributions	150,585	175,922
Current liabilities	0	0
Noncurrent liabilities	(521,773)	(441,814)
Net amount recognized	(521,773)	(441,814)
Actuarial loss	904,214	699,709
Prior service cost	1,959	2,762
Total amount recognized in accumulated other comprehensive loss	906,173	702,471
Non-Qualified Plans [Member]
Pension Benefits
Benefit obligation	277,060	253,743	230,602
Service cost	1,660	1,896	1,687
Interest cost	13,293	13,602	14,431
Plan participants’ contributions	0	0
Actuarial loss	25,621	25,333
Curtailments	0	0
Benefits paid	(17,224)	(17,367)
Effects of change in currency conversion	(33)	(323)
Fair value of plan assets	0	0	0
Actual return on plan assets	0	0
Employer contributions	17,224	17,367
Current liabilities	(18,784)	(16,436)
Noncurrent liabilities	(258,276)	(237,307)
Net amount recognized	(277,060)	(253,743)
Actuarial loss	99,130	76,723
Prior service cost	0	0
Total amount recognized in accumulated other comprehensive loss	$ 99,130	$ 76,723