Income Taxes (Additional Information) (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended		12 Months Ended
	Feb. 28, 2018	Jul. 28, 2018	Jan. 27, 2018	Jul. 28, 2018	Jul. 29, 2017	Jul. 30, 2016	Dec. 31, 2017
Income Tax [Line Items]
Blended federal tax rate				27.00%	35.00%	35.00%
Undistributed earnings of certain foreign subsidiaries on which tax is not provided		$ 77		$ 77			$ 76,000
Tax Cuts and Jobs Act of 2017, tax expense for foreign withholding tax			$ 1,200	1,200
Foreign earnings repatriated				70,000
Tax Cuts and Jobs Act of 2017, transition tax expense		(863)	9,000	8,100
Tax Cuts and Jobs Act of 2017, provisional tax expense			11,100	10,400
Tax Cuts and Jobs Act of 2017, re-measurement of net deferred tax assets			$ 900	1,100
Unrecognized deferred income tax liability		15		15
Gross income tax benefit attributable to tax incentives				$ 900	$ 1,300	$ 1,200
Gross Income Tax Benefit attributable to tax incentives (in dollars per share)				$ 0.19	$ 0.25	$ 0.23
Unrecognized Tax Benefits, reduced				$ 129	$ 78	$ 457
Unrecognized tax benefits that would affect the effective tax rate if realized		1,700		1,700
Net interest expense, reduction related to unrecognized tax benefits				10	26
Penalties, reduction related to unrecognized tax benefits				1	4
Reduction in net interest expense						55
Reduction in penalties						40
Accrual for interest and penalties		180		180	$ 186	154
Unrecognized tax benefit that could be reduced in next 12 months		300		300
Tax Year 2016
Income Tax [Line Items]
R&D tax benefit						226
Tax Year 2015
Income Tax [Line Items]
R&D tax benefit						81
Foreign Tax Authority
Income Tax [Line Items]
Income taxes paid	$ 1,200			1,200
Operating loss carryforwards		808		808
Valuation allowance		125		125
Tax credit carryforward		5		5
Federal income tax settlement (Year 2008-2010)
Income Tax [Line Items]
Unrecognized Tax Benefits, reduced						563
Accrued income tax interest reduction, tax settlement						63
Federal income tax settlement (Year 2008-2010) | Include reduction of interest expense
Income Tax [Line Items]
Net tax benefit to the income tax provision						367
Federal income tax settlement (Year 2008-2010) | Reduced tax interest expense upon tax settlement
Income Tax [Line Items]
Net tax benefit to the income tax provision						$ 21
Federal
Income Tax [Line Items]
Operating loss carryforwards		703		703
Tax credit carryforward		47		47
State and Local Jurisdiction
Income Tax [Line Items]
Operating loss carryforwards		891		891
Tax credit carryforward		1,000		1,000
Valuation allowance		$ 249		$ 249