Goodwill and Purchased Intangible Assets, Net - Amortization Expense for Purchased Intangible Assets (Detail) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Oct. 27, 2017	Oct. 28, 2016	Oct. 27, 2017	Oct. 28, 2016
Acquired Finite Lived Intangible Assets [Line Items]
Amortization expense	$ 14	$ 11	$ 27	$ 22
Cost of revenues \| Developed Technology
Acquired Finite Lived Intangible Assets [Line Items]
Amortization expense	9	7	17	13
Operating expenses \| Customer Contracts/Relationships
Acquired Finite Lived Intangible Assets [Line Items]
Amortization expense	4	3	8	7
Operating expenses \| Other Purchased Intangibles
Acquired Finite Lived Intangible Assets [Line Items]
Amortization expense	$ 1	$ 1	$ 2	$ 2

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16225-109274

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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Balance Type:	debit
Period Type:	duration