Other Operating Expense, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 26, 2016	Mar. 28, 2015
Other operating expense, net:
(Gain) loss on property, plant and equipment disposals	$ 120	$ (6)
Loss on currency exchanges	94	343
Amortization of intangibles	76	76
Retirement expenses	39	33
Miscellaneous (income) expense	(62)	44
Other operating expense, net	$ 267	$ 490