Employee Benefits Plans (Details) - Components of other postretirement benefit cost: (Other Postretirement Benefit Plan, Defined Benefit [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 29, 2014	Mar. 30, 2013
Other Postretirement Benefit Plan, Defined Benefit [Member]
Employee Benefits Plans (Details) - Components of other postretirement benefit cost: [Line Items]
Interest cost	$ 27	$ 25
Amortization of prior service benefit	(38)	(41)
Amortization of accumulated loss	3	8
Net periodic postretirement benefit income	$ (8)	$ (8)