Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2016	Apr. 04, 2015
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance as of December 31, 2015	$ (1,199)
Other comprehensive income before reclassifications	322
Amounts reclassified from accumulated OCI	46
Net other comprehensive income	368	$ 144
Balance as of April 2, 2016	(831)
Investments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance as of December 31, 2015	(378)
Other comprehensive income before reclassifications	322
Amounts reclassified from accumulated OCI	0
Net other comprehensive income	322
Balance as of April 2, 2016	(56)
Post Retirement Obligations
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance as of December 31, 2015	(821)
Other comprehensive income before reclassifications	0
Amounts reclassified from accumulated OCI	46
Net other comprehensive income	46
Balance as of April 2, 2016	$ (775)