Fair Value Measurements (Schedule Of Financial Assets And Liabilities Subject To Fair Value Measurement Provisions) (Details) (USD $) In Thousands, unless otherwise specified	Apr. 01, 2012	Dec. 31, 2011
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value	$ 107,342	$ 115,263
Total liabilities at fair value	(1,121)	(1,801)
Level 1 [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value	102,900	110,723
Total liabilities at fair value
Level 2 [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value	4,442	4,540
Total liabilities at fair value	(1,121)	(1,801)
Level 3 [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value
Total liabilities at fair value
Derivative Instruments - Liabilities [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total liabilities at fair value	(1,121)	(1,801)
Derivative Instruments - Liabilities [Member] | Level 1 [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total liabilities at fair value
Derivative Instruments - Liabilities [Member] | Level 2 [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total liabilities at fair value	(1,121)	(1,801)
Derivative Instruments - Liabilities [Member] | Level 3 [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total liabilities at fair value
Cash And Cash Equivalents [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value	85,524	95,278
Cash And Cash Equivalents [Member] | Level 1 [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value	85,524	95,278
Cash And Cash Equivalents [Member] | Level 2 [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value
Cash And Cash Equivalents [Member] | Level 3 [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value
Money Market Funds [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value	17,173	15,275
Money Market Funds [Member] | Level 1 [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value	17,173	15,275
Money Market Funds [Member] | Level 2 [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value
Money Market Funds [Member] | Level 3 [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value
Certificates Of Deposit [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value	3,643	3,555
Certificates Of Deposit [Member] | Level 1 [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value
Certificates Of Deposit [Member] | Level 2 [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value	3,643	3,555
Certificates Of Deposit [Member] | Level 3 [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value
Stock [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value	203	170
Stock [Member] | Level 1 [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value	203	170
Stock [Member] | Level 2 [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value
Stock [Member] | Level 3 [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value
Derivative Instruments - Assets [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value	799	985
Derivative Instruments - Assets [Member] | Level 1 [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value
Derivative Instruments - Assets [Member] | Level 2 [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value	799	985
Derivative Instruments - Assets [Member] | Level 3 [Member]
Fair Value Asset And Liabilities Measured On Recurring Basis [Line Items]
Total assets at fair value