Pre-Production Costs Related to Long-Term Supply Arrangements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 25, 2016	Dec. 31, 2015	Dec. 31, 2014
Accounting Policies [Abstract]
Deferred tooling revenue, revenue recognized	$ 8,000	$ 5,800	$ 8,200
Unamortized Preproduction Costs [Abstract]
Preproduction costs	78,299	73,095
Accumulated amortization	(65,100)	(58,632)
Net preproduction costs	13,199	14,463
Deferred Revenue [Abstract]
Accrued expenses	5,419	2,908
Other non-current liabilities	2,593	1,266
Total deferred tooling revenues	$ 8,012	$ 4,174