Other Operating (Income) Expense, Net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 01, 2017	Jun. 25, 2016	Jul. 01, 2017	Jun. 25, 2016
Other operating (income) expense, net:
Loss on property, plant and equipment disposals	$ 41	$ 139	$ 41	$ 259
(Gain) loss on currency exchanges	(15)	(97)	2	(3)
Amortization of intangibles	76	76	153	153
Retirement expenses	54	36	72	75
Miscellaneous (income) expense	(170)	(36)	(229)	(99)
Other operating (income) expense, net	$ (14)	$ 118	$ 39	$ 385