Goodwill and Purchased Intangible Assets (Details 2) (USD $)	9 Months Ended	12 Months Ended
	Jul. 31, 2011	Oct. 31, 2010
Purchased intangible assets
Amortizable purchased intangible assets, gross	$ 9,371,000,000	$ 11,071,000,000
Amortizable purchased intangible assets, accumulated amortization	(4,206,000,000)	(4,946,000,000)
Amortizable purchased intangible assets, net	5,165,000,000	6,125,000,000
Purchased intangible assets, gross	10,935,000,000	12,794,000,000
Purchased intangible assets, net	6,729,000,000	7,848,000,000
Intangible assets that have reached end of amortization period	4,500,000,000	2,500,000,000
Customer contracts, customer lists and distribution agreements
Purchased intangible assets
Amortizable purchased intangible assets, gross	5,242,000,000	7,075,000,000
Amortizable purchased intangible assets, accumulated amortization	(2,205,000,000)	(3,436,000,000)
Amortizable purchased intangible assets, net	3,037,000,000	3,639,000,000
Developed and core technology and patents
Purchased intangible assets
Amortizable purchased intangible assets, gross	3,929,000,000	3,797,000,000
Amortizable purchased intangible assets, accumulated amortization	(1,882,000,000)	(1,418,000,000)
Amortizable purchased intangible assets, net	2,047,000,000	2,379,000,000
Product trademarks
Purchased intangible assets
Amortizable purchased intangible assets, gross	200,000,000	199,000,000
Amortizable purchased intangible assets, accumulated amortization	(119,000,000)	(92,000,000)
Amortizable purchased intangible assets, net	81,000,000	107,000,000
In-process research and development
Purchased intangible assets
Indefinite-lived purchased intangible assets	142,000,000	301,000,000
Compaq trade name
Purchased intangible assets
Indefinite-lived purchased intangible assets, trade names	1,422,000,000	1,422,000,000
Vertica Systems, Inc.
Purchased intangible assets
Purchased intangible assets, gross	$ 58,000,000