Investments (Gross Realized Gains And Gross Realized Losses Related To Available-For-Sale Investment) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Jul. 27, 2013	Jul. 28, 2012	Jul. 30, 2011
Investments [Abstract]
Gross realized gains	$ 264	$ 561	$ 322
Gross realized losses	(216)	(460)	(143)
Total	$ 48	$ 101	$ 179

This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563

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- Definition

This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

+ References

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- Definition

This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

+ References

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