Marketable Securities (Tables)

6 Months Ended

Jul. 28, 2013

Notes to financial statements [Abstract]

Cash Equivalents and Marketable Securities

	July 28, 2013
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
	(In thousands)
Debt securities of United States government agencies	$	691,223	$	634	$	(393	)	$	691,464
Corporate debt securities	965,222		1,637		(914		)	965,945
Mortgage backed securities issued by United States government-sponsored enterprises	191,265		5,114		(362		)	196,017
Money market funds	164,885		—		—			164,885
Debt securities issued by United States Treasury	496,789		487		(130		)	497,146
Total	$	2,509,384	$	7,872	$	(1,799	)	$	2,515,457
Classified as:
Cash equivalents								$	170,885
Marketable securities								2,344,572
Total								$	2,515,457

	January 27, 2013
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
	(In thousands)
Debt securities of United States government agencies	$	867,087	$	1,199	$	(139	)	$	868,147
Corporate debt securities	1,255,297		3,175		(542		)	1,257,930
Mortgage backed securities issued by United States government-sponsored enterprises	183,034		6,194		(57		)	189,171
Money market funds	195,790		—		—			195,790
Debt securities issued by United States Treasury	785,228		1,102		(105		)	786,225
Total	$	3,286,436	$	11,670	$	(843	)	$	3,297,263
Classified as:
Cash equivalents								$	302,166
Marketable securities								2,995,097
Total								$	3,297,263

Schedule of Cash Equivalents and Marketable Securities Available for Sale

	July 28, 2013				January 27, 2013
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
	(In thousands)
Less than one year	$	991,260	$	992,324	$	1,397,350	$	1,399,304
Due in 1 - 5 years	1,430,967		1,434,002		1,777,785		1,783,103
Mortgage-backed securities issued by government-sponsored enterprises not due at a single maturity date	87,157		89,131		111,301		114,856
Total	$	2,509,384	$	2,515,457	$	3,286,436	$	3,297,263