Accumulated Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 29, 2013	Jun. 30, 2012	Jun. 29, 2013	Jun. 30, 2012
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance as of December 31, 2012			$ 43
Other comprehensive income before reclassifications			(86)
Amounts reclassified from accumulated OCI			(84)
Net other comprehensive income (loss)	(57)	(19)	(170)	(34)
Balance as of June 29, 2013	(127)		(127)
Investments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance as of December 31, 2012			25
Other comprehensive income before reclassifications			(86)
Amounts reclassified from accumulated OCI			0
Net other comprehensive income (loss)			(86)
Balance as of June 29, 2013	(61)		(61)
Post Retirement Obligations
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance as of December 31, 2012			(71)
Other comprehensive income before reclassifications			0
Amounts reclassified from accumulated OCI			5
Net other comprehensive income (loss)			5
Balance as of June 29, 2013	(66)		(66)
Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance as of December 31, 2012			89
Other comprehensive income before reclassifications			0
Amounts reclassified from accumulated OCI			(89)
Net other comprehensive income (loss)			(89)
Balance as of June 29, 2013	$ 0		$ 0