Supplemental Financial Information - Product Warranty Liabilities (Detail) - USD ($) $ in Millions	3 Months Ended
	Jul. 31, 2020	Jul. 26, 2019	Jul. 31, 2020	Apr. 24, 2020
Movement In Standard Product Warranty Accrual [Roll Forward]
Balance at beginning of period	$ 41	$ 40
Expense accrued during the period	1	5
Warranty costs incurred	(5)	(6)
Balance at end of period	37	39
Standard Product Warranty Accrual, Balance Sheet Classification [Abstract]
Accrued expenses			$ 24	$ 26
Other long-term liabilities			13	15
Total warranty liabilities	$ 37	$ 39	$ 37	$ 41