CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jul. 01, 2012	Jun. 30, 2013	Jul. 01, 2012
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 24,620	$ 58,713	$ 43,052	$ 133,910
Other comprehensive (loss)/income before tax:
Foreign currency translation adjustments	(4,965)	(4,844)	(5,307)	(3,397)
Available-for-sale securities:
Unrealized (loss)/gain on investments	(5,396)	195	(3,416)	533
Reclassification of net realized (gain)/loss on investments to net income	(1)	(560)	16	(702)
Derivative financial instruments:
Unrealized loss on derivatives	(1,619)	(1,989)	(1,651)	(1,349)
Reclassification of net realized (gain)/loss on derivatives to net income	(140)	1,335	(302)	2,008
Amortization of net actuarial loss, prior service cost and transition asset on defined benefit pension and post-retirement plans	5,253	4,183	10,297	8,152
Other comprehensive (loss)/income before tax	(6,868)	(1,680)	(363)	5,245
Income tax benefit on unrealized loss on investments	(740)
Other comprehensive (loss)/income, net of tax	(6,128)	(1,680)	(363)	5,245
Comprehensive income	$ 18,492	$ 57,033	$ 42,689	$ 139,155