Description of Business and Significant Accounting Policies (Narrative) (Details)	3 Months Ended	6 Months Ended
	Jul. 01, 2017	Jul. 01, 2017
Basis Of Presentation Fiscal Year End And New Accounting Pronouncements Disclosure [Abstract]
Operating Cycle		The fiscal year of the Company consists of a 52- or 53-week period ending on the Saturday closest to December 31. Fiscal year 2017 is a 52-week period ending on December 30, 2017, with quarterly periods ending on April 1, July 1 and September 30, 2017. Fiscal year 2016 was a 52-week period ending on December 31, 2016, with quarterly periods ending on April 2, July 2 and October 1, 2016.
Year Founded	1973