Employee Benefits (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 29, 2014	Mar. 30, 2013
Pension Benefits [Member]
Components of net periodic benefit cost [Abstract]
Service cost	$ 222	$ 375
Interest cost	2,068	2,030
Expected return on plan assets	(3,201)	(2,798)
Amortization of net (gain) loss	188	992
Net periodic benefit (income) cost	(723)	599
Other Benefits [Member]
Components of net periodic benefit cost [Abstract]
Service cost	89	68
Interest cost	177	280
Amortization of prior service cost	0	2
Amortization of net (gain) loss	(64)	(26)
Net periodic benefit (income) cost	$ 202	$ 324