Schedule of Available for Sale Marketable Securities (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 29, 2013	Dec. 31, 2012
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	$ 584,299	$ 663,625
Available-for-sale marketable securities, Unrealized Gain	3,514	3,862
Available-for-sale marketable securities, Unrealized (Loss)	(1,392)	(99)
Available-for-sale marketable securities, Fair Market Value	586,421	667,388
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	150,973	59,100
U.S. Government Agency Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	229,133	217,396
Available-for-sale marketable securities, Unrealized Gain	142	262
Available-for-sale marketable securities, Unrealized (Loss)	(146)	(3)
Available-for-sale marketable securities, Fair Market Value	229,129	217,655
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	103,165	9,018
U.S. Treasury Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	211,966	311,915
Available-for-sale marketable securities, Unrealized Gain	140	216
Available-for-sale marketable securities, Unrealized (Loss)	(150)	(15)
Available-for-sale marketable securities, Fair Market Value	211,956	312,116
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	5,605	1,018
Commercial Paper
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	88,884	70,431
Available-for-sale marketable securities, Unrealized Gain	12	9
Available-for-sale marketable securities, Unrealized (Loss)	(5)	(6)
Available-for-sale marketable securities, Fair Market Value	88,891	70,434
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	25,169	25,209
Corporate Debt Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	44,132	53,405
Available-for-sale marketable securities, Unrealized Gain	905	2,414
Available-for-sale marketable securities, Unrealized (Loss)	(1,055)	(64)
Available-for-sale marketable securities, Fair Market Value	43,982	55,755
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	16,439	23,255
Equity And Debt Mutual Funds
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	9,843	8,767
Available-for-sale marketable securities, Unrealized Gain	2,315	961
Available-for-sale marketable securities, Unrealized (Loss)	(36)	(11)
Available-for-sale marketable securities, Fair Market Value	12,122	9,717
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	595	600
Certificates Of Deposit And Time Deposits
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	261	1,627
Available-for-sale marketable securities, Fair Market Value	261	1,627
Non-U.S. Government Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	80	84
Available-for-sale marketable securities, Fair Market Value	$ 80	$ 84