Pension Benefits - Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Details) (USD $)	12 Months Ended
	Dec. 29, 2013	Dec. 30, 2012	Dec. 25, 2011
Pension Benefits
Defined contribution plan, cost recognized	$ 18,000,000	$ 23,000,000	$ 23,000,000
Pension Plans, Defined Benefit [Member]
Pension Benefits
Net actuarial (gain)/loss	(178,088,000)	96,551,000	246,672,000
Prior service credit	0	(31,839,000)	0
Amortization of loss	(39,017,000)	(37,813,000)	(28,060,000)
Amortization of prior service cost	1,945,000	(574,000)	(803,000)
Effect of settlement	(3,358,000)	(47,657,000)	0
Total recognized in other comprehensive (income)/loss	(218,518,000)	(21,332,000)	217,809,000
Net periodic pension cost	16,568,000	82,702,000	42,107,000
Total recognized in net periodic benefit cost and other comprehensive loss	(201,950,000)	61,370,000	259,916,000
Estimated actuarial loss that will be amortized from accumulated other comprehensive loss into net periodic pension cost over the next fiscal year	31,000,000
Estimated prior service credit that will be amortized from accumulated other comprehensive loss into net periodic pension cost over the next fiscal year	$ 2,000,000