Goodwill and Purchased Intangible Assets (Schedule Of Intangible Assets Acquired Through Business Combinations) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jul. 27, 2013	Jul. 28, 2012	Jul. 30, 2011
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Amount, acquired indefinite lives intangible assets	$ 194	$ 0
Business Combination, Purchased intangible assets	645	200	114
Technology-Based Intangible Assets [Member]
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Amount, acquired finite lives	1,286	199
Customer Relationships
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Amount, acquired finite lives	883	1
Other Intangible Assets [Member]
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Amount, acquired finite lives	28	0
NDS Group Ltd [Member]
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Amount, acquired indefinite lives intangible assets	94
Business Combination, Purchased intangible assets	1,746
NDS Group Ltd [Member] | Technology-Based Intangible Assets [Member]
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Weighted-Average Useful Life (in Years)	6 years 4 months 24 days
Amount, acquired finite lives	807
NDS Group Ltd [Member] | Customer Relationships
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Weighted-Average Useful Life (in Years)	6 years 8 months 4 days
Amount, acquired finite lives	818
NDS Group Ltd [Member] | Other Intangible Assets [Member]
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Weighted-Average Useful Life (in Years)	7 years 4 months 24 days
Amount, acquired finite lives	27
Meraki Inc [Member]
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Amount, acquired indefinite lives intangible assets	0
Business Combination, Purchased intangible assets	289
Meraki Inc [Member] | Technology-Based Intangible Assets [Member]
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Weighted-Average Useful Life (in Years)	8 years
Amount, acquired finite lives	259
Meraki Inc [Member] | Customer Relationships
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Weighted-Average Useful Life (in Years)	6 years
Amount, acquired finite lives	30
Meraki Inc [Member] | Other Intangible Assets [Member]
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Amount, acquired finite lives	0
Intucell Ltd [Member]
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Amount, acquired indefinite lives intangible assets	36
Business Combination, Purchased intangible assets	106
Intucell Ltd [Member] | Technology-Based Intangible Assets [Member]
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Weighted-Average Useful Life (in Years)	5 years
Amount, acquired finite lives	59
Intucell Ltd [Member] | Customer Relationships
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Weighted-Average Useful Life (in Years)	5 years
Amount, acquired finite lives	11
Intucell Ltd [Member] | Other Intangible Assets [Member]
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Amount, acquired finite lives	0
Ubiquisys Ltd [Member]
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Amount, acquired indefinite lives intangible assets	50
Business Combination, Purchased intangible assets	123
Ubiquisys Ltd [Member] | Technology-Based Intangible Assets [Member]
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Weighted-Average Useful Life (in Years)	4 years
Amount, acquired finite lives	66
Ubiquisys Ltd [Member] | Customer Relationships
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Weighted-Average Useful Life (in Years)	5 years
Amount, acquired finite lives	7
Ubiquisys Ltd [Member] | Other Intangible Assets [Member]
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Amount, acquired finite lives	0
Light Wire [Member]
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Amount, acquired indefinite lives intangible assets		0
Business Combination, Purchased intangible assets		97
Light Wire [Member] | Technology-Based Intangible Assets [Member]
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Weighted-Average Useful Life (in Years)		5 years
Amount, acquired finite lives		97
Light Wire [Member] | Customer Relationships
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Amount, acquired finite lives		0
Light Wire [Member] | Other Intangible Assets [Member]
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Amount, acquired finite lives		0
Other Acquisitions [Member]
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Amount, acquired indefinite lives intangible assets	14	0
Business Combination, Purchased intangible assets	127	103
Other Acquisitions [Member] | Technology-Based Intangible Assets [Member]
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Weighted-Average Useful Life (in Years)	4 years 8 months 12 days	3 years 6 months
Amount, acquired finite lives	95	102
Other Acquisitions [Member] | Customer Relationships
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Weighted-Average Useful Life (in Years)	5 years 9 months 18 days	3 years
Amount, acquired finite lives	17	1
Other Acquisitions [Member] | Other Intangible Assets [Member]
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Weighted-Average Useful Life (in Years)	5 years
Amount, acquired finite lives	1	0
Total acquisitions for the period [Member]
Schedule of Finite Lived and Indefinite Lived Intangible Assets Acquired Through Business Combinations [Line Items]
Business Combination, Purchased intangible assets	$ 2,391	$ 200