Fair Value Measurement, Financial Instruments And Risk Management (Fair Values Of Derivative Instruments Included Within The Consolidated Balance Sheets) (Details) - USD ($) $ in Thousands	Mar. 27, 2016	Dec. 27, 2015
Derivatives, Fair Value [Line Items]
Asset Derivatives	$ 43	$ 109
Liability Derivatives	629	135
Foreign currency revenue forecast contracts
Derivatives, Fair Value [Line Items]
Asset Derivatives	5
Liability Derivatives	306	135
Foreign currency forward exchange contracts
Derivatives, Fair Value [Line Items]
Asset Derivatives	38	109
Liability Derivatives	323
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Asset Derivatives	5	0
Liability Derivatives	306	135
Designated as Hedging Instrument | Foreign currency revenue forecast contracts | Other current assets
Derivatives, Fair Value [Line Items]
Asset Derivatives	5	0
Designated as Hedging Instrument | Foreign currency revenue forecast contracts | Other current liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	306	135
Derivatives not designated as hedging instruments:
Derivatives, Fair Value [Line Items]
Asset Derivatives	38	109
Liability Derivatives	323	0
Derivatives not designated as hedging instruments: | Foreign currency forward exchange contracts | Other current assets
Derivatives, Fair Value [Line Items]
Asset Derivatives	38	109
Derivatives not designated as hedging instruments: | Foreign currency forward exchange contracts | Other current liabilities
Derivatives, Fair Value [Line Items]
Liability Derivatives	$ 323	$ 0