Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended	12 Months Ended
	Jul. 31, 2016	May 01, 2016	Jul. 31, 2016	Jan. 29, 2017		Jan. 31, 2016	Jan. 25, 2015
Current Income Tax Expense
Federal				$ 7		$ (43)	$ 8
State				1		1	1
Foreign				34		25	17
Total current				42		(17)	26
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal				199		134	84
State				0		0	0
Foreign				(2)		0	(1)
Total deferred				197		134	83
Charge in lieu of taxes attributable to employer stock option plans				0		12	15
Income tax expense	$ 56	$ 33	$ 89	239		129	124
Income before Income Taxes
Domestic				600		129	174
Foreign				1,305		614	581
Income before income tax expense				$ 1,905		743	755
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate				35.00%
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Tax expense computed at federal statutory rate				$ 667		260	264
State income taxes, net of federal tax effect				4		1	1
Foreign tax rate differential				(315)		(95)	(120)
U.S. federal R&D tax credit				(52)		(38)	(34)
Stock-based compensation				(70)	[1]	13	4
Tax expense related to inter-company transaction				10		10	10
Restructuring and expiration of statute of limitations				0		(21)	0
Other				(5)		(1)	(1)
Income tax expense	$ 56	$ 33	$ 89	239		129	$ 124
Excess Tax Benefit Related To Stock Based Compensation				82
Components of Deferred Tax Assets [Abstract]
Net operating loss carryforwards				199	[2]	57
Accruals and reserves, not currently deductible for tax purposes				40		58
Property, equipment and intangible assets				50		50
Research and other tax credit carryforwards				728	[2]	404
Stock-based compensation				34		29
Convertible debt				6		9
Gross deferred tax assets				1,057		607
Less valuation allowance				(353)	[2]	(272)
Deferred Tax Assets, Net				704		335
Components of Deferred Tax Liabilities [Abstract]
Acquired intangibles				(11)		(17)
Unremitted earnings of foreign subsidiaries				(827)		(615)
Deferred Tax Liabilities, Gross				(838)		(632)
Net deferred tax asset (liability)				$ (134)		$ (297)
Effective tax rate				12.50%		17.30%	16.50%
Operating Loss Carryforwards [Line Items]
Unrecognized tax benefit related to state tax positions				$ 27
Deferred Tax Assets, Operating Loss Carryforwards, Foreign				219
Undistributed Earnings Of Non United States Subsidiaries				3,130
UNITED STATES
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards				448
Deferred Tax Assets, Tax Credit Carryforwards, Research				541
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards				446
Deferred Tax Assets, Tax Credit Carryforwards, Research				476
CALIFORNIA
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Tax Credit Carryforwards, Research				457
Other states
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Tax Credit Carryforwards, Research				19
Foreign Country
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards				$ 219

[1] We adopted an accounting standard related to stock-based compensation effective February 1, 2016, which required the excess tax benefit to be reflected in our provision for income taxes rather than in additional paid-in-capital. The total related excess tax benefit recognized for fiscal year 2017 was $82 million. Please refer to Note 1 of these Notes to the Consolidated Financial Statements for additional information.

[2] Balances as of January 29, 2017 reflect the adoption of an accounting standard related to stock-based compensation. Please refer to Note 1 of these Notes to the Consolidated Financial Statements for additional information.