Purchased Intangible Assets, Net - Purchased Intangible Assets, Net (Detail) - USD ($) $ in Millions	Jul. 31, 2015	Apr. 24, 2015
Acquired Finite Lived Intangible Assets [Line Items]
Gross Assets	$ 310	$ 321
Accumulated Amortization	(246)	(231)
Net Assets	64	90
Developed Technology
Acquired Finite Lived Intangible Assets [Line Items]
Gross Assets	304	313
Accumulated Amortization	(242)	(225)
Net Assets	62	88
Customer Contracts/Relationships
Acquired Finite Lived Intangible Assets [Line Items]
Gross Assets	5	5
Accumulated Amortization	(3)	(3)
Net Assets	2	2
Other Purchased Intangibles
Acquired Finite Lived Intangible Assets [Line Items]
Gross Assets	1	3
Accumulated Amortization	(1)	(3)
Net Assets	$ 0	$ 0