Balance Sheet Details - Product Warranty Liabilities (Detail) - USD ($) $ in Millions	3 Months Ended
	Jul. 31, 2015	Jul. 25, 2014	Jul. 31, 2015	Apr. 24, 2015
Movement In Standard Product Warranty Accrual [Roll Forward]
Balance at beginning of period	$ 86	$ 110
Expense accrued during the period	9	10
Warranty costs incurred	(14)	(16)
Balance at end of period	81	104
Standard Product Warranty Accrual, Balance Sheet Classification [Abstract]
Accrued expenses			$ 54	$ 58
Other long-term liabilities			27	28
Total warranty liabilities	$ 86	$ 110	$ 81	$ 86