Income Taxes - Unrecognized Tax Benefits (Detail) - USD ($) $ in Millions	6 Months Ended
Oct. 30, 2015	Oct. 24, 2014
Income Tax Disclosure [Abstract]
Balance at beginning of period	$ 272	$ 236
Additions based on tax positions related to the current year	7	13
Additions for tax positions of prior years	20	99
Decreases for tax positions of prior years	(38)	(19)
Settlements	(52)	(54)
Balance at end of period	$ 209	$ 275

No definition available.

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- Definition

Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 15A

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=SL6600010-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Unrecognized Tax Benefit

-URI http://asc.fasb.org/extlink&oid=6527854

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- Definition

Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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- Definition

Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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