Marketable Securities (Tables)

9 Months Ended

Oct. 28, 2012

Notes to financial statements [Abstract]

Cash Equivalents and Marketable Securities

	October 28, 2012
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
	(In thousands)
Debt securities of United States government agencies	$	846,587	$	1,175	$	(166	)	$	847,596
Corporate debt securities	1,187,944		3,841		(127		)	1,191,658
Mortgage backed securities issued by United States government-sponsored enterprises	184,488		6,321		(148		)	190,661
Money market funds	85,030		—		—			85,030
Debt securities issued by United States Treasury	694,591		980		(105		)	695,466
Total	$	2,998,640	$	12,317	$	(546	)	$	3,010,411
Classified as:
Cash equivalents								$	101,027
Marketable securities								2,909,384
Total								$	3,010,411

	January 29, 2012
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
	(In thousands)
Debt securities of United States government agencies	$	769,300	$	1,605	$	(151	)	$	770,754
Corporate debt securities	1,114,439		3,268		(260		)	1,117,447
Mortgage backed securities issued by United States government-sponsored enterprises	156,668		4,964		(73		)	161,559
Money market funds	290,732		—		—			290,732
Debt securities issued by United States Treasury	533,616		2,161		(3		)	535,774
Total	$	2,864,755	$	11,998	$	(487	)	$	2,876,266
Classified as:
Cash equivalents								$	414,566
Marketable securities								2,461,700
Total								$	2,876,266

Schedule of Cash Equivalents and Marketable Securities Available for Sale

	October 28, 2012				January 29, 2012
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
	(In thousands)
Less than one year	$	1,301,359	$	1,303,269	$	1,705,916	$	1,708,154
Due in 1 - 5 years	1,582,124		1,588,451		1,047,956		1,053,265
Mortgage-backed securities issued by government-sponsored enterprises not due at a single maturity date	115,157		118,691		110,883		114,847
Total	$	2,998,640	$	3,010,411	$	2,864,755	$	2,876,266