Benefit Plans (Details 1) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Jan. 01, 2012
Components of Net Periodic Benefit Cost
Service cost	$ 774	$ 645
Interest cost	787	667
Amortization of: Prior service cost	569	0
Net loss	193	62
Net periodic pension cost	$ 2,323	$ 1,374
Weighted Average Assumptions for Expense
Discount rate	4.40%	5.50%
Rate of compensation increase, percentage	4.60%	4.29%