Pre-Production Costs Related to Long-Term Supply Arrangements (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 24, 2012	Jun. 30, 2013	Jun. 24, 2012	Dec. 30, 2012
Unamortized Preproduction Costs [Abstract]
Preproduction costs	$ 56,394,000		$ 56,394,000		$ 51,638,000
Accumulated amortization	(42,273,000)		(42,273,000)		(38,667,000)
Net preproduction costs	14,121,000		14,121,000		12,971,000
Deferred Revenue [Abstract]
Accrued expenses	5,801,000		5,801,000		5,688,000
Other non-current liabilities	3,369,000		3,369,000		3,443,000
Total deferred tooling revenues	9,170,000		9,170,000		9,131,000
Deferred Revenue, Revenue Recognized	$ 2,900,000	$ 1,800,000	$ 4,800,000	$ 3,900,000