Financial Instruments And Derivatives (Schedule Of Available-For-Sale Marketable Securities) (Details) (USD $) In Thousands, unless otherwise specified	Apr. 01, 2012	Dec. 31, 2011
Schedule of Available-For-Sale Marketable Securities [Line Items]
Available-for-sale marketable securities, Cost	$ 568,115	$ 591,118
Available-for-sale marketable securities, Unrealized Gain	2,689	2,581
Available-for-sale marketable securities, Unrealized (Loss)	(127)	(297)
Available-for-sale marketable securities, Fair Market Value	570,677	593,402
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	61,704	64,571
Money Market Funds [Member]
Schedule of Available-For-Sale Marketable Securities [Line Items]
Available-for-sale marketable securities, Cost	350,544	396,329
Available-for-sale marketable securities, Unrealized Gain
Available-for-sale marketable securities, Unrealized (Loss)
Available-for-sale marketable securities, Fair Market Value	350,544	396,329
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses
U.S. Government Agency Securities [Member]
Schedule of Available-For-Sale Marketable Securities [Line Items]
Available-for-sale marketable securities, Cost	91,178	83,070
Available-for-sale marketable securities, Unrealized Gain	163	152
Available-for-sale marketable securities, Unrealized (Loss)	(48)	(25)
Available-for-sale marketable securities, Fair Market Value	91,293	83,197
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	26,014	28,510
Corporate Debt Securities [Member]
Schedule of Available-For-Sale Marketable Securities [Line Items]
Available-for-sale marketable securities, Cost	44,602	43,077
Available-for-sale marketable securities, Unrealized Gain	1,514	1,893
Available-for-sale marketable securities, Unrealized (Loss)	(47)	(141)
Available-for-sale marketable securities, Fair Market Value	46,069	44,829
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	13,295	17,033
Commercial Paper [Member]
Schedule of Available-For-Sale Marketable Securities [Line Items]
Available-for-sale marketable securities, Cost	33,542	29,932
Available-for-sale marketable securities, Unrealized Gain	6	2
Available-for-sale marketable securities, Unrealized (Loss)	(9)	(10)
Available-for-sale marketable securities, Fair Market Value	33,539	29,924
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	9,482	9,479
Certificates Of Deposit And Time Deposits [Member]
Schedule of Available-For-Sale Marketable Securities [Line Items]
Available-for-sale marketable securities, Cost	16,186	16,437
Available-for-sale marketable securities, Unrealized Gain
Available-for-sale marketable securities, Unrealized (Loss)	(3)	(5)
Available-for-sale marketable securities, Fair Market Value	16,183	16,432
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	5,810	5,800
U.S. Treasury Securities [Member]
Schedule of Available-For-Sale Marketable Securities [Line Items]
Available-for-sale marketable securities, Cost	23,568	14,141
Available-for-sale marketable securities, Unrealized Gain	50	39
Available-for-sale marketable securities, Unrealized (Loss)	(18)
Available-for-sale marketable securities, Fair Market Value	23,600	14,180
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	6,968
Equity And Debt Mutual Funds [Member]
Schedule of Available-For-Sale Marketable Securities [Line Items]
Available-for-sale marketable securities, Cost	8,230	7,876
Available-for-sale marketable securities, Unrealized Gain	939	477
Available-for-sale marketable securities, Unrealized (Loss)	(2)	(116)
Available-for-sale marketable securities, Fair Market Value	9,167	8,237
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	135	3,749
Non-U.S. Government Securities [Member]
Schedule of Available-For-Sale Marketable Securities [Line Items]
Available-for-sale marketable securities, Cost	265	256
Available-for-sale marketable securities, Unrealized Gain	17	18
Available-for-sale marketable securities, Unrealized (Loss)
Available-for-sale marketable securities, Fair Market Value	282	274
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

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This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities.

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- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

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