Schedule of Available for Sale Marketable Securities (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 28, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	$ 965,843	$ 855,786
Available-for-sale marketable securities, Unrealized Gain	4,260	3,689
Available-for-sale marketable securities, Unrealized (Loss)	(494)	(1,515)
Available-for-sale marketable securities, Fair Market Value	969,609	857,960
Available-for-sale marketable securities, Fair Market Value of Investment with Unrealized Losses	212,156	241,760
U.S. Government Agency Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	285,528	202,573
Available-for-sale marketable securities, Unrealized Gain	195	75
Available-for-sale marketable securities, Unrealized (Loss)	(106)	(60)
Available-for-sale marketable securities, Fair Market Value	285,617	202,588
Available-for-sale marketable securities, Fair Market Value of Investment with Unrealized Losses	66,700	84,498
U.S. Treasury Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	458,958	468,084
Available-for-sale marketable securities, Unrealized Gain	373	94
Available-for-sale marketable securities, Unrealized (Loss)	(91)	(283)
Available-for-sale marketable securities, Fair Market Value	459,240	467,895
Available-for-sale marketable securities, Fair Market Value of Investment with Unrealized Losses	64,267	108,212
Commercial Paper
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	99,767	105,583
Available-for-sale marketable securities, Unrealized Gain	11	16
Available-for-sale marketable securities, Unrealized (Loss)	(4)	(1)
Available-for-sale marketable securities, Fair Market Value	99,774	105,598
Available-for-sale marketable securities, Fair Market Value of Investment with Unrealized Losses	23,722	7,993
Corporate Debt Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	92,883	65,747
Available-for-sale marketable securities, Unrealized Gain	1,734	762
Available-for-sale marketable securities, Unrealized (Loss)	(260)	(1,122)
Available-for-sale marketable securities, Fair Market Value	94,357	65,387
Available-for-sale marketable securities, Fair Market Value of Investment with Unrealized Losses	56,393	40,355
Equity And Debt Mutual Funds
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	10,199	10,463
Available-for-sale marketable securities, Unrealized Gain	1,933	2,742
Available-for-sale marketable securities, Unrealized (Loss)	(33)	(49)
Available-for-sale marketable securities, Fair Market Value	12,099	13,156
Available-for-sale marketable securities, Fair Market Value of Investment with Unrealized Losses	1,074	702
Certificates of Deposit and Time Deposits
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	18,508	3,258
Available-for-sale marketable securities, Unrealized Gain	14
Available-for-sale marketable securities, Fair Market Value	18,522	3,258
Non-U.S. Government Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost		78
Available-for-sale marketable securities, Fair Market Value		$ 78