Fair Value Measurements (Tables)

12 Months Ended

Mar. 31, 2012

Fair Value Measurements [Abstract]

Assets and Liabilities Measured at Fair Value on a Recurring Basis

	March 31, 2012
	Quoted Prices in Active Markets for Identical Instruments		Significant Other Observable Inputs		Significant Unobservable Inputs		Total Fair
(In thousands)	(Level 1)		(Level 2)		(Level 3)		Value
Assets
Cash and cash equivalents:
Money market funds	$	232,017	$	—	$	—	$	232,017
Bank certificates of deposit		—		29,994		—		29,994
Commercial paper		—		233,980		—		233,980
U.S. government and agency securities		75,036		84,985		—		160,021
Foreign government and agency securities		—		68,993		—		68,993
Short-term investments:
Bank certificates of deposit		—		129,978		—		129,978
Commercial paper		—		360,887		—		360,887
Corporate bonds		—		14,257		—		14,257
U.S. government and agency securities		322,763		119,931		—		442,694
Foreign government and agency securities		—		180,958		—		180,958
Mortgage-backed securities		—		31		—		31
Long-term investments:
Corporate bonds		—		175,415		—		175,415
Auction rate securities		—		—		28,929		28,929
Municipal bonds		—		26,160		—		26,160
U.S. government and agency securities		17,539		48,659		—		66,198
Mortgage-backed securities		—		892,745		—		892,745
Debt mutual fund		—		19,781		—		19,781
Total assets measured at fair value	$	647,355	$	2,386,754	$	28,929	$	3,063,038
Liabilities
Derivative financial instruments, net	$	—	$	3,070	$	—	$	3,070
Convertible debentures – embedded derivative		—		—		931		931
Total liabilities measured at fair value	$	—	$	3,070	$	931	$	4,001
Net assets measured at fair value	$	647,355	$	2,383,684	$	27,998	$	3,059,037

	April 2, 2011
	Quoted Prices in Active Markets for Identical Instruments		Significant Other Observable Inputs		Significant Unobservable Inputs		Total Fair
(In thousands)	(Level 1)		(Level 2)		(Level 3)		Value
Assets
Cash and cash equivalents:
Money market funds	$	275,596	$	—	$	—	$	275,596
Bank certificates of deposit		—		79,984		—		79,984
Commercial paper		—		485,315		—		485,315
U.S. government and agency securities		29,998		99,974		—		129,972
Foreign government and agency securities		—		161,970		—		161,970
Short-term investments:
Bank certificates of deposit		—		10,000		—		10,000
Commercial paper		—		224,896		—		224,896
Municipal bonds		—		45		—		45
U.S. government and agency securities		14,404		7,996		—		22,400
Foreign government and agency securities		—		384,428		—		384,428
Floating rate notes		—		62,261		—		62,261
Mortgage-backed securities		—		24		—		24
Long-term investments:
Corporate bonds		—		25,566		—		25,566
Auction rate securities		—		—		34,950		34,950
Municipal bonds		—		16,913		—		16,913
U.S. government and agency securities		7,941		45,570		—		53,511
Floating rate notes		—		29,869		—		29,869
Mortgage-backed securities		—		605,643		—		605,643
Derivative financial instruments, net		—		5,134		—		5,134
Total assets measured at fair value	$	327,939	$	2,245,588	$	34,950	$	2,608,477
Liabilities
Convertible debentures – embedded derivative	$	—	$	—	$	945	$	945
Total liabilities measured at fair value	$	—	$	—	$	945	$	945
Net assets measured at fair value	$	327,939	$	2,245,588	$	34,005	$	2,607,532

Changes in Level 3 instruments measured at fair value on a recurring basis

(In thousands)	Year Ended March 31, 2012			Year Ended April 2, 2011
Balance as of beginning of period	$	34,005		$	60,796
Total realized and unrealized gains (losses):
Included in interest and other expense, net		14			(676	)
Included in other comprehensive income		(371	)		4,255
Sales and settlements, net (1)		(5,650	)		(30,370	)
Balance as of end of period	$	27,998		$	34,005

Gains or (losses) included in net income attributable to change in unrealized gains or losses relating to assets and liabilities

(In thousands)	March 31, 2012		April 2, 2011			April 3, 2010
Interest and other expense, net	$	14	$	(97	)	$	1,262