Balance Sheet Details - Product Warranty Liabilities (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Oct. 27, 2017	Oct. 28, 2016	Oct. 27, 2017	Oct. 28, 2016	Oct. 27, 2017	Apr. 28, 2017
Movement In Standard Product Warranty Accrual [Roll Forward]
Balance at beginning of period	$ 44	$ 61	$ 50	$ 70
Expense accrued during the period	7	1	8	5
Warranty costs incurred	(7)	(8)	(14)	(21)
Balance at end of period	44	54	44	54
Standard Product Warranty Accrual, Balance Sheet Classification [Abstract]
Accrued expenses					$ 29	$ 33
Other long-term liabilities					15	17
Total warranty liabilities	$ 44	$ 61	$ 50	$ 70	$ 44	$ 50