Summary of Significant Accounting Policies Concentration (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($)	Dec. 25, 2016	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Concentration Risk [Line Items]
Research and Development Expense	$ 3.8		$ 2.6	$ 4.4
Description of Foreign Currency Exposure		.19
Supplier Concentration Risk [Member]
Concentration Risk [Line Items]
Vendors Accounting for More Than Ten Percent of Aluminum Purchases	2