Purchased Intangible Assets, Net - Amortization Expense for Purchased Intangible Assets (Detail) - USD ($) $ in Millions	3 Months Ended
	Jul. 29, 2016	Jul. 31, 2015
Acquired Finite Lived Intangible Assets [Line Items]
Amortization expense	$ 11	$ 14
Cost of revenues | Developed Technology
Acquired Finite Lived Intangible Assets [Line Items]
Amortization expense	6	14
Operating expenses | Customer Contracts/Relationships
Acquired Finite Lived Intangible Assets [Line Items]
Amortization expense	4	0
Operating expenses | Other Purchased Intangibles
Acquired Finite Lived Intangible Assets [Line Items]
Amortization expense	$ 1	$ 0