Income Taxes (Details) - USD ($)	3 Months Ended		6 Months Ended
	Oct. 26, 2018	Oct. 27, 2017	Oct. 26, 2018	Oct. 27, 2017	Apr. 27, 2018
Income Tax Disclosure [Abstract]
Tax Cuts and Jobs Act of 2017, measurement period adjustment to transition tax liability	$ 37,000,000		$ (13,000,000)
Tax Cuts and Jobs Act of 2017, total provisional transition tax charge	2,500,000,000		2,500,000,000
Tax Cuts and Jobs Act of 2017, remeasure of deferred tax assets, liabilities, and valuation allowances, provisional tax benefit	$ 0		$ 0
Effective tax rate	17.30%	(16.50%)	13.30%	(3.40%)
Certain tax adjustments	$ 58,000,000	$ (404,000,000)	$ 29,000,000	$ (344,000,000)
Tax Cuts and Jobs Act of 2017, charge related to recognition of prepaid tax expense	21,000,000		42,000,000
Tax benefit associated with intercompany sales of intellectual property		398,000,000		398,000,000
Tax charge (benefit) related to tax effect from certain restructuring steps taken in anticipation of divestiture		$ (6,000,000)		$ 54,000,000
Gross unrecognized tax benefits	1,700,000,000		1,700,000,000		$ 1,700,000,000
Accrued gross interest and penalties	170,000,000		170,000,000
Unrecognized tax benefits that would impact effective tax rate	$ 1,700,000,000		$ 1,700,000,000