Supplemental Financial Information - Product Warranty Liabilities (Detail) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Oct. 26, 2018	Oct. 27, 2017	Oct. 26, 2018	Oct. 27, 2017	Oct. 26, 2018	Apr. 27, 2018
Movement In Standard Product Warranty Accrual [Roll Forward]
Balance at beginning of period	$ 38	$ 44	$ 40	$ 50
Expense accrued during the period	6	7	10	8
Warranty costs incurred	(5)	(7)	(11)	(14)
Balance at end of period	39	44	39	44
Standard Product Warranty Accrual, Balance Sheet Classification [Abstract]
Accrued expenses					$ 26	$ 25
Other long-term liabilities					13	15
Total warranty liabilities	$ 38	$ 44	$ 40	$ 50	$ 39	$ 40

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Amount as of the balance sheet date of the aggregate standard product warranty liability. Does not include the balance for the extended product warranty liability.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (c)(1),(c)(5)
-URI http://asc.fasb.org/extlink&oid=68068213&loc=d3e12565-110249

+ Details

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- References

No definition available.

+ Details

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- Definition

Amount as of the balance sheet date of the aggregate standard product warranty liability that is expected to be paid within one year or the normal operating cycle, if longer. Does not include the balance for the extended product warranty liability.

+ References

No definition available.

+ Details

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- Definition

Amount as of the balance sheet date of the aggregate standard product warranty liability that is expected to be paid after one year or beyond the normal operating cycle, if longer. Does not include the balance for the extended product warranty liability.

+ References

No definition available.

+ Details

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- Definition

Amount of decrease in the standard product warranty accrual from payments made in cash or in kind to satisfy claims under the terms of the standard product warranty. Excludes extended product warranties.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph ((c)(2))
-URI http://asc.fasb.org/extlink&oid=68068213&loc=d3e12565-110249

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- Definition

Amount of increase in the standard product warranty accrual from warranties issued. Excludes extended product warranties.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph ((c)(3))
-URI http://asc.fasb.org/extlink&oid=68068213&loc=d3e12565-110249

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