Other Postretirement Benefits - Schedule of Components of Net Periodic Postretirement Benefit Income (Details) (Other Postretirement Benefit Plans, Defined Benefit [Member], USD $) In Thousands, unless otherwise specified	1 Months Ended	12 Months Ended
	Jan. 31, 2012	Dec. 30, 2012	Dec. 25, 2011	Dec. 26, 2010
Other Postretirement Benefit Plans, Defined Benefit [Member]
Other Postretirement Benefits
Service cost		$ 957	$ 1,143	$ 1,076
Interest cost		4,985	6,890	9,340
Recognized actuarial loss		3,328	2,289	3,129
Amortization of prior service credit		(15,112)	(16,593)	(15,602)
Effect of curtailment	(27,200)	(27,213)	0	0
Net periodic postretirement benefit income		$ (33,055)	$ (6,271)	$ (2,057)