Other Liabilities (Details) - USD ($) $ in Thousands	Apr. 01, 2017	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
Deferred compensation	$ 6,762	$ 6,100
Asset retirement obligation	2,748	2,706
Post-retirement medical obligation	1,888	1,869
Deferred service income-long term	895	1,145
Deferred rent	587	610
Deferred income tax liabilities - long term	324	0
Long-term income taxes payable	27	26
Balance, end of the period	$ 13,231	$ 12,456	[1]

[1] The balance sheet as of December 31, 2016 has been derived from the audited financial statements at that date.