Change In Accounting Principle (Schedule Of Condensed Consolidated Statements Of Comprehensive Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Apr. 01, 2012	Apr. 03, 2011
Change in Accounting Principle [Line Items]
Net income	$ 33,564	$ 96,844
Foreign currency translation reclassification adjustment included in net income		2,266
Unrealized gains on investments	278	15
Pension and post-retirement costs: Prior service costs, net of tax of $0		6
Defined benefit pension and post-retirement plans, total		6
Other comprehensive income	186	2,287
Comprehensive income	33,750	99,131
Originally Reported [Member]
Change in Accounting Principle [Line Items]
Net income		94,872
Foreign currency translation reclassification adjustment included in net income		2,266
Unrealized gains on investments		15
Defined benefit pension and post-retirement plans: Actuarial losses arising during period, net of tax of ($15), $15		(51)
Defined benefit pension and post-retirement plans: Actuarial losses tax portion		(15)
Defined benefit pension and post-retirement plans: Settlement gain, net of tax of $35, ($35)		60
Defined benefit pension and post-retirement plans: Settlement gain, tax portion		35
Pension and post-retirement costs: Actuarial losses, net of tax of $11, ($11)		2,078
Pension and post-retirement costs: Actuarial losses, tax portion		11
Pension and post-retirement costs: Prior service costs, net of tax of $0		6
Pension and post-retirement costs: Prior service costs, tax portion	0
Defined benefit pension and post-retirement plans, total		2,093
Other comprehensive income		4,374
Comprehensive income		99,246
Effect Of Accounting Change [Member]
Change in Accounting Principle [Line Items]
Net income		1,972
Defined benefit pension and post-retirement plans: Actuarial losses arising during period, net of tax of ($15), $15		51
Defined benefit pension and post-retirement plans: Actuarial losses tax portion		15
Defined benefit pension and post-retirement plans: Settlement gain, net of tax of $35, ($35)		(60)
Defined benefit pension and post-retirement plans: Settlement gain, tax portion		(35)
Pension and post-retirement costs: Actuarial losses, net of tax of $11, ($11)		(2,078)
Pension and post-retirement costs: Actuarial losses, tax portion		(11)
Defined benefit pension and post-retirement plans, total		(2,087)
Other comprehensive income		(2,087)
Comprehensive income		(115)
As Adjusted [Member]
Change in Accounting Principle [Line Items]
Net income		$ 96,844