Schedule of Condensed Consolidated Statements of Comprehensive Income (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Oct. 02, 2011	Sep. 30, 2012	Oct. 02, 2011
Change In Accounting Principle
Net income	$ 88,641	$ 56,706	$ 233,592	$ 240,802
Foreign currency translation reclassification adjustment included in net income				2,266
Unrealized gains on marketable securities	1,166	(1,057)	1,872	256
Prior service costs, net of tax of $0 for 3 months and 9 months ended Oct. 2, 2011	(92)	5	(275)	17
Other comprehensive income	1,074	(1,052)	1,597	2,539
Comprehensive income	89,715	55,654	235,189	243,341
Originally Reported
Change In Accounting Principle
Net income		54,745		238,675
Foreign currency translation reclassification adjustment included in net income				2,266
Unrealized gains on marketable securities		(1,057)		256
Actuarial losses arising during period, net of tax of ($0), $0 for 3 months and ($5), $5 for 9 months ended Oct. 2, 2011		(5)		(4,206)
Settlement loss, net of tax of $73, ($73) for 9 months ended Oct. 2, 2012				277
Actuarial losses, net of tax of $11, ($11) for 3 months and $30, ($30) for 9 months ended Oct. 2, 2011		2,226		6,681
Prior service costs, net of tax of $0 for 3 months and 9 months ended Oct. 2, 2011		5		17
Defined benefit pension and post-retirement plans, total		2,231		6,698
Other comprehensive income		1,169		5,291
Comprehensive income		55,914		243,966
Effect Of Accounting Change
Change In Accounting Principle
Net income		1,961		2,127
Actuarial losses arising during period, net of tax of ($0), $0 for 3 months and ($5), $5 for 9 months ended Oct. 2, 2011		5		4,206
Settlement loss, net of tax of $73, ($73) for 9 months ended Oct. 2, 2012				(277)
Actuarial losses, net of tax of $11, ($11) for 3 months and $30, ($30) for 9 months ended Oct. 2, 2011		(2,226)		(6,681)
Defined benefit pension and post-retirement plans, total		(2,226)		(6,681)
Other comprehensive income		(2,221)		(2,752)
Comprehensive income		(260)		(625)
As Adjusted
Change In Accounting Principle
Net income		56,706		240,802
Foreign currency translation reclassification adjustment included in net income				2,266
Unrealized gains on marketable securities		(1,057)		256
Prior service costs, net of tax of $0 for 3 months and 9 months ended Oct. 2, 2011		5		17
Defined benefit pension and post-retirement plans, total		5		17
Other comprehensive income		(1,052)		2,539
Comprehensive income		$ 55,654		$ 243,341