v2.4.0.8
Property plant and equipment (Narrative) (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 28, 2013
Dec. 29, 2012
Dec. 31, 2011
Property, Plant and Equipment [Line Items]      
Property, Plant and Equipment, Gross $ 273,173 $ 241,024  
Property, Plant and Equipment 158,073 140,579  
Machinery and Equipment [Member]
     
Property, Plant and Equipment [Line Items]      
Property, Plant and Equipment, Gross 174,454 153,204  
Property, Plant and Equipment 93,949 83,363  
Inventory, Parts and Components, Net of Reserves 3,577 2,913  
Depreciation 17,666 15,293 13,935
Machinery and Equipment [Member] | Construction in Progress [Member]
     
Property, Plant and Equipment [Line Items]      
Property, Plant and Equipment, Gross 10,263 13,475  
Machinery and Equipment [Member] | Capital Lease [Member]
     
Property, Plant and Equipment [Line Items]      
Property, Plant and Equipment, Gross 7,807 1,132  
Property, Plant and Equipment $ 7,517 $ 994