Derivative Instruments And Hedging Activities (Schedule Of Fair Values Of Derivative Instruments Included In Company's Condensed Consolidated Balance Sheets) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 30, 2014	Dec. 28, 2013
Foreign Currency Exchange Derivatives [Member] | Designated As A Hedge [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value	$ (204)	$ (350)
Natural Gas Collar [Member] | Not Designated As A Hedge [Member]
Derivatives, Fair Value [Line Items]
Natural gas collar	304	245
Interest Rate Swap [Member] | Designated As A Hedge [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments in Hedges, Assets, at Fair Value	$ (1,568)	$ (914)