v2.4.0.8
Description of business and significant accounting policies (Narrative) (Details)
12 Months Ended
Jan. 03, 2015
Dec. 28, 2013
Basis Of Presentation Fiscal Year End And New Accounting Pronouncements Disclosure [Abstract]    
Year Founded   1973
Finite-Lived Intangible Assets [Line Items]    
Fiscal Period Duration 371 days 364 days
Maximum [Member] | Customer Relationships [Member]
   
Finite-Lived Intangible Assets [Line Items]    
Finite Lived Intangible Asset Useful Life   25 years
Maximum [Member] | Patents And Trademarks [Member]
   
Finite-Lived Intangible Assets [Line Items]    
Finite Lived Intangible Asset Useful Life   15 years
Maximum [Member] | Other Intangible Assets [Member]
   
Finite-Lived Intangible Assets [Line Items]    
Finite Lived Intangible Asset Useful Life   15 years
Minimum [Member] | Customer Relationships [Member]
   
Finite-Lived Intangible Assets [Line Items]    
Finite Lived Intangible Asset Useful Life   2 years
Minimum [Member] | Patents And Trademarks [Member]
   
Finite-Lived Intangible Assets [Line Items]    
Finite Lived Intangible Asset Useful Life   7 years
Minimum [Member] | Other Intangible Assets [Member]
   
Finite-Lived Intangible Assets [Line Items]    
Finite Lived Intangible Asset Useful Life   3 years
Buildings [Member] | Maximum [Member]
   
Property, Plant and Equipment [Line Items]    
Property Plant And Equipment Useful Life   40 years
Buildings [Member] | Minimum [Member]
   
Property, Plant and Equipment [Line Items]    
Property Plant And Equipment Useful Life   20 years
Machinery and Equipment [Member] | Maximum [Member]
   
Property, Plant and Equipment [Line Items]    
Property Plant And Equipment Useful Life   20 years
Machinery and Equipment [Member] | Minimum [Member]
   
Property, Plant and Equipment [Line Items]    
Property Plant And Equipment Useful Life   10 years
Enterprise Software [Member]
   
Property, Plant and Equipment [Line Items]    
Property Plant And Equipment Useful Life   5 years
Office Furniture and Equipment [Member] | Maximum [Member]
   
Property, Plant and Equipment [Line Items]    
Property Plant And Equipment Useful Life   7 years
Office Furniture and Equipment [Member] | Minimum [Member]
   
Property, Plant and Equipment [Line Items]    
Property Plant And Equipment Useful Life   3 years
Vehicles [Member]
   
Property, Plant and Equipment [Line Items]    
Property Plant And Equipment Useful Life   5 years
Opta Minerals Inc [Member]
   
Noncontrolling Interest [Line Items]    
Noncontrolling Interest, Ownership Percentage by Parent   66.00%
Mascoma [Member]
   
Noncontrolling Interest [Line Items]    
Cost Method Investments Percentage   19.00%