Other Operating Expense, Net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 25, 2016	Jun. 27, 2015	Jun. 25, 2016	Jun. 27, 2015
Other operating expense, net:
(Gain) loss on property, plant and equipment disposals	$ 139	$ (103)	$ 259	$ (108)
(Gain) loss on currency exchanges	(97)	102	(3)	445
Amortization of intangibles	76	76	153	153
Retirement expenses	36	58	75	90
Miscellaneous (income) expense	(36)	(70)	(99)	(27)
Other operating expense, net	$ 118	$ 63	$ 385	$ 553