Marketable Securities (Tables)

3 Months Ended

Apr. 26, 2015

Notes to financial statements [Abstract]

Cash Equivalents and Marketable Securities

	April 26, 2015
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
	(In millions)
Corporate debt securities	$	2,214	$	4	$	(1	)	$	2,217
Debt securities of United States government agencies	968		1		—			969
Asset-backed securities	480		—		—			480
Debt securities issued by United States Treasury	415		1		—			416
Mortgage-backed securities issued by United States government-sponsored enterprises	260		4		—			264
Foreign government bonds	81		—		—			81
Money market funds	19		—		—			19
Total	$	4,437	$	10	$	(1	)	$	4,446
Classified as:
Cash equivalents								$	118
Marketable securities								4,328
Total								$	4,446

	January 25, 2015
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
	(In millions)
Corporate debt securities	$	2,185	$	2	$	(1	)	$	2,186
Debt securities of United States government agencies	750		1		(1		)	750
Asset-backed securities	453		—		—			453
Debt securities issued by United States Treasury	534		3		—			537
Mortgage-backed securities issued by United States government-sponsored enterprises	274		5		(1		)	278
Foreign government bonds	85		—		—			85
Money market funds	132		—		—			132
Total	$	4,413	$	11	$	(3	)	$	4,421
Classified as:
Cash equivalents								$	295
Marketable securities								4,126
Total								$	4,421

Schedule of Unrealized Loss on Investments [Table Text Block]

	Less than 12 months					12 months or greater				Total
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
	(In millions)
Corporate debt securities	$	573	$	(1	)	$	13	$	—	$	586	$	(1	)
Debt securities of United States government agencies	309		—			9		—		318		—
Asset-backed securities	257		—			3		—		260		—
Mortgage-backed securities issued by United States government-sponsored enterprises	74		—			18		—		92		—
Debt securities issued by United States Treasury	58		—			—		—		58		—
Foreign government bonds	14		—			—		—		14		—
Total	$	1,285	$	(1	)	$	43	$	—	$	1,328	$	(1	)

Schedule of Cash Equivalents and Marketable Securities Available for Sale

	April 26, 2015				January 25, 2015
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
	(In millions)
Less than 1 year	$	1,445	$	1,445	$	1,570	$	1,571
Due in 1 - 5 years	2,866		2,872		2,720		2,726
Mortgage-backed securities issued by government-sponsored enterprises not due at a single maturity date	126		129		123		124
Total	$	4,437	$	4,446	$	4,413	$	4,421