Marketable Securities (Tables)

6 Months Ended

Jul. 30, 2017

Schedule of Available-for-sale Securities [Line Items]

Cash Equivalents and Marketable Securities

	July 30, 2017
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value		Reported as
										Cash Equivalents		Marketable Securities
	(In millions)
Corporate debt securities	$	1,664	$	1	$	(5	)	$	1,660	$	—	$	1,660
Debt securities of United States government agencies	1,030		—		(4		)	1,026		—		1,026
Debt securities issued by the United States Treasury	658		—		(2		)	656		—		656
Asset-backed securities	330		—		(1		)	329		—		329
Mortgage-backed securities issued by United States government-sponsored enterprises	153		2		(1		)	154		—		154
Foreign government bonds	64		—		—			64		—		64
Money market funds	1,663		—		—			1,663		1,663		—
Total	$	5,562	$	3	$	(13	)	$	5,552	$	1,663	$	3,889

	January 29, 2017
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value		Reported as
										Cash Equivalents		Marketable Securities
	(In millions)
Corporate debt securities	$	2,397	$	1	$	(10	)	$	2,388	$	33	$	2,355
Debt securities of United States government agencies	1,193		—		(5		)	1,188		27		1,161
Debt securities issued by the United States Treasury	852		—		(2		)	850		55		795
Asset-backed securities	490		—		(1		)	489		—		489
Mortgage-backed securities issued by United States government-sponsored enterprises	161		2		(1		)	162		—		162
Foreign government bonds	70		—		—			70		—		70
Money market funds	321		—		—			321		321		—
Total	$	5,484	$	3	$	(19	)	$	5,468	$	436	$	5,032

Schedule of Unrealized Loss on Investments

	Less than 12 Months					12 Months or Greater					Total
	Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses			Estimated Fair Value		Gross Unrealized Losses
	(In millions)
Corporate debt securities	$	1,243	$	(4	)	$	86	$	(1	)	$	1,329	$	(5	)
Debt securities issued by United States government agencies	881		(3		)	100		(1		)	981		(4		)
Debt securities issued by the United States Treasury	645		(2		)	—		—			645		(2		)
Asset-backed securities	304		(1		)	—		—			304		(1		)
Mortgage-backed securities issued by United States government-sponsored enterprises	40		—			36		(1		)	76		(1		)
	$	3,113	$	(10	)	$	222	$	(3	)	$	3,335	$	(13	)

Schedule of Amortization Cost and Estimated FV of CE and MS

	July 30, 2017				January 29, 2017
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
	(In millions)
Less than 1 year	$	3,086	$	3,085	$	2,209	$	2,209
Due in 1 - 5 years	2,423		2,414		3,210		3,194
Mortgage-backed securities issued by United States government-sponsored enterprises not due at a single maturity date	53		53		65		65
Total	$	5,562	$	5,552	$	5,484	$	5,468