Manufacturing Restructuring Costs (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013
Restructuring Cost and Reserve [Line Items]
Manufacturing restructuring costs	$ 0	$ 0	$ (331)	$ 0
Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Manufacturing restructuring costs	0	0	(331)	0
Restructuring Reserve [RollForward]
Balance at the beginning of the period	2,109	2,946	2,772	3,387
Accretion of related lease obligations	120	118	372	394
Payments	(185)	(207)	(769)	(924)
Balance at the end of the period	$ 2,044	$ 2,857	$ 2,044	$ 2,857