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Employee Benefits (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 25, 2017
Apr. 01, 2017
Apr. 02, 2016
Compensation and Retirement Disclosure [Abstract]      
Service cost   $ 183 $ 252
Interest cost on projected benefit obligation   1,178 1,271
Expected return on plan assets   (1,584) (1,551)
Amortization of unrecognized loss   268 223
Net periodic pension cost   $ 45 $ 195
Multiemployer plans, withdrawal obligation $ 4,500    
Multiemployer plans, withdrawal obligation repayment period 20 years