Employee Benefits (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012	Dec. 28, 2013
Pension Benefits [Member]
Employee benefits
Service cost	$ 822	$ 922	$ 2,492	$ 2,880
Interest cost	2,762	2,824	8,334	8,445
Expected return on plan assets	(3,593)	(3,459)	(10,842)	(10,319)
Amortization of prior service cost (credit)	(147)	(256)	(444)	(566)
Amortization of net loss (gain)	671	586	2,043	1,756
Net periodic benefit cost	515	617	1,583	2,196
Expected contributions during the current fiscal year					9,686
Supplemental Retirement Benefits [Member]
Employee benefits
Service cost	160	160	482	480
Interest cost	177	223	531	669
Expected return on plan assets	0	0	0	0
Amortization of prior service cost (credit)	165	165	495	495
Amortization of net loss (gain)	63	65	189	195
Net periodic benefit cost	$ 565	$ 613	$ 1,697	$ 1,839