Fair Value Measurement, Financial Instruments And Risk Management (Fair Values Of Derivative Instruments Included Within The Consolidated Balance Sheets) (Details) - USD ($) $ in Thousands	Dec. 27, 2015	Dec. 28, 2014
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	$ 109	$ 55
Derivative Liabilities, Fair Value	135	23
Foreign currency revenue forecast contracts
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value	135
Foreign currency forward exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	109	55
Derivative Liabilities, Fair Value		23
Derivatives designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	0	0
Derivative Liabilities, Fair Value	135	0
Derivatives designated as hedging instruments | Foreign currency revenue forecast contracts | Other current assets
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	0	0
Derivatives designated as hedging instruments | Foreign currency revenue forecast contracts | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value	135	0
Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	109	55
Derivative Liabilities, Fair Value	0	23
Derivatives not designated as hedging instruments | Foreign currency forward exchange contracts | Other current assets
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	109	55
Derivatives not designated as hedging instruments | Foreign currency forward exchange contracts | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value	0	23
Fair Value, Inputs, Level
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	0	0
Derivative Liabilities, Fair Value	0	0
Fair Value, Inputs, Level | Foreign currency revenue forecast contracts
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value	0
Fair Value, Inputs, Level | Foreign currency forward exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	0	0
Derivative Liabilities, Fair Value		0
Fair Value, Inputs, Level 2
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	109	55
Derivative Liabilities, Fair Value	135	23
Fair Value, Inputs, Level 2 | Foreign currency revenue forecast contracts
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value	135
Fair Value, Inputs, Level 2 | Foreign currency forward exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	109	55
Derivative Liabilities, Fair Value		23
Fair Value, Inputs, Level 3
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	0	0
Derivative Liabilities, Fair Value	0	0
Fair Value, Inputs, Level 3 | Foreign currency revenue forecast contracts
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value	0
Fair Value, Inputs, Level 3 | Foreign currency forward exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	$ 0	0
Derivative Liabilities, Fair Value		$ 0