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	12 Months Ended
	Dec. 28, 2014	Dec. 29, 2013	Dec. 30, 2012
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	$ 580	$ 1,089	$ 957
Interest cost	3,722	4,101	4,985
Amortization and other costs	7,299	4,440	3,328
Amortization of prior service credit	(7,199)	(13,051)	(15,112)
Effect of curtailment	0	(49,122)	(27,213)
Net periodic postretirement benefit expense/(income)	$ 4,402	$ (52,543)	$ (33,055)