Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended	12 Months Ended
	Apr. 27, 2018	Jan. 26, 2018	Jan. 26, 2018	Apr. 27, 2018	Apr. 28, 2017
Income Tax Contingency [Line Items]
U.S. federal corporate tax rate			35.00%
Discrete tax expense on deferred tax assets and liabilities		$ 117
Percentage of transition tax on accumulated foreign earnings and profits, due to TCJA			15.50%
Percentage of transition tax on remaining foreign earnings due to TCJA			8.00%
Discrete tax expense for the estimated U.S. federal and state income tax impacts of the transition tax		739
Payment period for one-time transition tax			8 years
Gross unrecognized tax benefits		338	$ 338
Unrecognized tax benefits included in other long-term liabilities		303	303		$ 148
Unrecognized tax benefits that would affect provision for income taxes		284	284
Unrecognized tax benefits		113	$ 113
Land and Building
Income Tax Contingency [Line Items]
Discrete tax expense related to the sale of certain buildings and land		$ 72
Scenario, Forecast
Income Tax Contingency [Line Items]
U.S. federal corporate tax rate	21.00%			30.50%