Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Oct. 25, 2019	Oct. 26, 2018	Oct. 25, 2019	Oct. 26, 2018	Apr. 26, 2019
Income Tax Disclosure [Abstract]
Effective tax rate	(6.00%)	17.30%	1.00%	13.30%
Certain tax adjustments	$ (251)	$ 58	$ (281)	$ 29
Benefit related to tax legislative changes in Switzerland	251		251
Net charge (benefit) related to measurement period adjustment related to U.S. Tax Reform		37	(30)	(13)
Charge related to recognition of prepaid tax expense		$ 21		$ 42
Gross unrecognized tax benefits	1,800		1,800		$ 1,800
Accrued gross interest and penalties	196		196
Unrecognized tax benefits that would impact effective tax rate	$ 1,800		$ 1,800
Amortizable Asset Created for Swiss Federal Income Tax Purposes
Finite-Lived Intangible Assets [Line Items]
Period over which amortizable asset will be amortized and deducted	10 years		10 years

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in foreign income tax contingency.

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Amount of increase (decrease) to previously recorded tax expense. Includes, but is not limited to, significant settlements of income tax disputes, and unusual tax positions or infrequent actions taken by the entity, including tax assessment reversal, and IRS tax settlement.

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Amount of reasonable estimate for income tax expense for which accounting for tax effect for remeasurement of deferred tax asset from change in tax rate is incomplete pursuant to Tax Cuts and Jobs Act.

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