Acquisitions (Details) (USD $)				12 Months Ended
	Oct. 31, 2013	Oct. 31, 2012	Oct. 31, 2011	Oct. 31, 2011 Acquisitions Item	Oct. 31, 2013 Digital Risk LLC MphasiS Limited	Oct. 31, 2011 Autonomy	Oct. 31, 2012 Autonomy
Acquisitions:
Number of acquisitions				4
Purchase price allocation
Total fair value of purchase consideration				$ 11,400,000,000	$ 174,000,000	$ 11,000,000,000
Goodwill	31,124,000,000	31,069,000,000	44,551,000,000	6,900,000,000	112,000,000		1,200,000,000
Intangible assets				4,700,000,000
Net liabilities assumed				$ 206,000,000