Summary of Significant Accounting Policies (Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 25, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of revenues - Foreign currency revenue forecast contracts	$ 94,894		$ 91,173
Total before tax	(3,786)		(10,902)
Tax benefit	(279)		10,196
Reclassification Out Of Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net of tax	(124)
Reclassification Out Of Accumulated Other Comprehensive Income (Loss) [Member] | Amortization of Pension Plan Items [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Actuarial loss	(389)	[1]
Prior service cost	(1)	[1]
Total before tax	(390)
Tax benefit	108
Net of tax	(282)
Reclassification Out Of Accumulated Other Comprehensive Income (Loss) [Member] | Gains and Losses on Cash flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of revenues - Foreign currency revenue forecast contracts	158
Total before tax	158
Tax benefit	0
Net of tax	$ 158

[1] These accumulated other comprehensive income components are included in the computation of net periodic pension costs. Refer to Note 9 of the Consolidated Financial Statements.