Marketable Securities (Details) (USD $) In Thousands, unless otherwise specified	Jan. 01, 2012	Apr. 03, 2011
Schedule of Available-For-Sale Securities
Available-for-sale securities, Amortized Cost	$ 321,037	$ 235,447
Available-for-sale securities, Gross Unrealized Gains	1,223	1,409
Available-for-sale securities, Gross Unrealized Losses	(633)	(560)
Available-for-sale securities, Estimated Fair Value	321,627	236,296
U.S. Government and agency securities [Member]
Schedule of Available-For-Sale Securities
Available-for-sale securities, Amortized Cost	121,512	55,875
Available-for-sale securities, Gross Unrealized Gains	233	94
Available-for-sale securities, Gross Unrealized Losses	(27)	(216)
Available-for-sale securities, Estimated Fair Value	121,718	55,753
Corporate debt obligations [Member]
Schedule of Available-For-Sale Securities
Available-for-sale securities, Amortized Cost	144,650	137,706
Available-for-sale securities, Gross Unrealized Gains	750	1,012
Available-for-sale securities, Gross Unrealized Losses	(531)	(282)
Available-for-sale securities, Estimated Fair Value	144,869	138,436
Asset and mortgage-backed securities [Member]
Schedule of Available-For-Sale Securities
Available-for-sale securities, Amortized Cost	38,895	22,249
Available-for-sale securities, Gross Unrealized Gains	218	293
Available-for-sale securities, Gross Unrealized Losses	(73)	(52)
Available-for-sale securities, Estimated Fair Value	39,040	22,490
Municipal bonds [Member]
Schedule of Available-For-Sale Securities
Available-for-sale securities, Amortized Cost	15,788	17,941
Available-for-sale securities, Gross Unrealized Gains	22	10
Available-for-sale securities, Gross Unrealized Losses	(2)	(10)
Available-for-sale securities, Estimated Fair Value	15,808	17,941
Non-U.S. government and agency securities [Member]
Schedule of Available-For-Sale Securities
Available-for-sale securities, Amortized Cost		1,676
Available-for-sale securities, Gross Unrealized Gains		0
Available-for-sale securities, Gross Unrealized Losses		0
Available-for-sale securities, Estimated Fair Value		1,676
Total debt securities [Member]
Schedule of Available-For-Sale Securities
Available-for-sale securities, Amortized Cost	320,845
Available-for-sale securities, Gross Unrealized Gains	1,223
Available-for-sale securities, Gross Unrealized Losses	(633)
Available-for-sale securities, Estimated Fair Value	321,435
Certificates of deposit [Member]
Schedule of Available-For-Sale Securities
Available-for-sale securities, Amortized Cost	192
Available-for-sale securities, Gross Unrealized Gains	0
Available-for-sale securities, Gross Unrealized Losses	0
Available-for-sale securities, Estimated Fair Value	$ 192

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 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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- Definition

This item represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

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