Investments (Maturities Of Fixed Income Securities) (Details) $ in Millions	Jul. 25, 2015 USD ($)
Schedule of Investments [Line Items]
Amortized Cost	$ 51,952
Fair Value	51,974
Less than 1 year
Schedule of Investments [Line Items]
Amortized Cost	16,534
Fair Value	16,540
Due in 1 to 2 years
Schedule of Investments [Line Items]
Amortized Cost	15,264
Fair Value	15,279
Due in 2 to 5 years
Schedule of Investments [Line Items]
Amortized Cost	18,501
Fair Value	18,499
Due after 5 years
Schedule of Investments [Line Items]
Amortized Cost	1,653
Fair Value	$ 1,656

Amount of available-for-sale debt securities at cost, net of adjustments, that do not have a single maturity date and which the entity has decided to disclose separately rather than allocating the cost over several maturity groupings. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less any cumulative-effect adjustments, as defined) and fair value hedge accounting adjustments.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27198-111563

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.2)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Amount of available-for-sale debt securities at fair value that do not have a single maturity date and which the entity has decided to disclose separately rather than allocating the fair value over several maturity groupings.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27198-111563

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