Description of Business and Significant Accounting Policies (Narrative) (Details)	9 Months Ended
	Oct. 01, 2016	Jan. 02, 2016
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 2016 is a 52-week period ending on December 31, 2016, with quarterly periods ending on April 2, July 2 and October 1, 2016. Fiscal year 2015 was a 52-week period ending on January 2, 2016, with quarterly periods ending on April 4, July 4 and October 3, 2015.
Year Founded	1973
Opta Minerals Inc [Member]
Noncontrolling Interest [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent		66.00%