Financial Instruments (Tables)

12 Months Ended

Mar. 31, 2012

Financial Instruments [Abstract]

Available-for-sale securities

	March 31, 2012									April 2, 2011
(In thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Money market funds	$	232,017	$	—	$	—		$	232,017	$	275,596	$	—	$	—		$	275,596
Bank certificates of deposit		159,972		—		—			159,972		89,984		—		—			89,984
Commercial paper		594,867		1		(1	)		594,867		710,210		2		(1	)		710,211
Corporate bonds		186,455		3,401		(184	)		189,672		25,501		69		(4	)		25,566
Auction rate securities		32,600		—		(3,671	)		28,929		38,250		—		(3,300	)		34,950
Municipal bonds		25,454		734		(28	)		26,160		16,818		192		(52	)		16,958
U.S. government and agency securities		668,702		360		(149	)		668,913		206,052		38		(207	)		205,883
Foreign government and agency securities		249,951		—		—			249,951		546,407		7		(16	)		546,398
Floating rate notes		—		—		—			—		91,927		204		(1	)		92,130
Mortgage-backed securities		878,842		15,094		(1,160	)		892,776		598,046		8,984		(1,363	)		605,667
Debt mutual fund		20,000		—		(219	)		19,781		—		—		—			—
		3,048,860		19,590		(5,412	)		3,063,038	$	2,598,791	$	9,496	$	(4,944	)	$	2,603,343

Fair values and gross unrealized losses of the investments

	April 2, 2011
	Less Than 12 Months					12 Months or Greater					Total
(In thousands)	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Losses
Commercial paper	$	44,982	$	(1	)	$	—	$	—		$	44,982	$	(1	)
Corporate bonds		6,129		(4	)		—		—			6,129		(4	)
Auction rate securities		—		—			34,950		(3,300	)		34,950		(3,300	)
Municipal bonds		4,992		(42	)		936		(10	)		5,928		(52	)
U.S. government and agency securities		108,464		(207	)		—		—			108,464		(207	)
Foreign government and agency securities		67,061		(16	)		—		—			67,061		(16	)
Floating rate notes		25,020		(1	)		—		—			25,020		(1	)
Mortgage-backed securities		178,844		(1,356	)		1,094		(7	)		179,938		(1,363	)
	$	435,492	$	(1,627	)	$	36,980	$	(3,317	)	$	472,472	$	(4,944	)

Amortized cost and estimated fair value of marketable debt securities

	March 31, 2012
(In thousands)	Amortized Cost		Estimated Fair Value
Due in one year or less	$	1,621,892	$	1,621,793
Due after one year through five years		255,577		259,584
Due after five years through ten years		266,223		270,742
Due after ten years		653,151		659,121
	$	2,796,843	$	2,811,240

Information on sale of available-for-sale securities

(In thousands)	2012			2011			2010
Gross realized gains on sale of available-for-sale securities	$	2,916		$	5,169		$	2,947
Gross realized losses on sale of available-for-sale securities		(401	)		(1,348	)		(2,596	)
Net realized gains on sale of available-for-sale securities	$	2,515		$	3,821		$	351
Amortization of premiums (discounts) on available-for-sale securities	$	13,302		$	7,650		$	(4,797	)