Restructuring Charges (Details) (USD $)	3 Months Ended		3 Months Ended	12 Months Ended	3 Months Ended	1 Months Ended	3 Months Ended		1 Months Ended	3 Months Ended	1 Months Ended	3 Months Ended	1 Months Ended	3 Months Ended
	Jan. 31, 2012	Oct. 31, 2011	Jan. 31, 2012 Fiscal 2010 Acquisitions	Oct. 31, 2011 Fiscal 2010 Acquisitions	Jan. 31, 2012 Fiscal 2010 ES Restructuring Plan	Jun. 30, 2010 Fiscal 2010 ES Restructuring Plan Severance position	Jan. 31, 2012 Fiscal 2010 ES Restructuring Plan Severance position	Jan. 31, 2012 Fiscal 2010 ES Restructuring Plan Infrastructure	May 31, 2009 Fiscal 2009 Restructuring Plan position	Jan. 31, 2012 Fiscal 2009 Restructuring Plan position	Aug. 31, 2008 Fiscal 2008 HP/EDS Restructuring Plan	Jan. 31, 2012 Fiscal 2008 HP/EDS Restructuring Plan	Aug. 31, 2008 Fiscal 2008 HP/EDS Restructuring Plan Severance position	Jan. 31, 2012 Fiscal 2008 HP/EDS Restructuring Plan Severance position	Jan. 31, 2012 Fiscal 2008 HP/EDS Restructuring Plan Infrastructure
Restructuring and related costs
Additional restructuring costs				$ 33,000,000
Expected positions to be eliminated						8,000			4,400				25,000
Positions eliminated							6,000			4,400				25,000
Implementation period (in years)											4 years
Costs reflected in purchase price of Electronic Data Systems Corporation ("EDS")											1,500,000,000
Restructuring Reserve
Balance at the beginning of the period	813,000,000		59,000,000		496,000,000		493,000,000	3,000,000				258,000,000			258,000,000
Charges	40,000,000				4,000,000		(100,000,000)	104,000,000		7,000,000		29,000,000		5,000,000	24,000,000
Cash payments	(174,000,000)		(15,000,000)		(110,000,000)		(42,000,000)	(68,000,000)		(7,000,000)		(42,000,000)		(5,000,000)	(37,000,000)
Non-cash settlements and other adjustments	(59,000,000)		(1,000,000)		(56,000,000)		(18,000,000)	(38,000,000)				(2,000,000)			(2,000,000)
Balance at the end of the period	620,000,000		43,000,000	59,000,000	334,000,000		333,000,000	1,000,000				243,000,000			243,000,000
Total costs and adjustments to date	4,528,000,000		114,000,000		920,000,000		623,000,000	297,000,000		301,000,000		3,193,000,000		2,195,000,000	998,000,000
Total expected costs and adjustments	4,776,000,000		121,000,000	121,000,000	992,000,000		623,000,000	369,000,000		301,000,000		3,362,000,000		2,195,000,000	1,167,000,000
Long-term portion of restructuring reserve, recorded in Other liabilities	258,000,000	159,000,000
Expected cost of the plan						1,000,000,000			301,000,000		3,400,000,000
Short-term portion of restructuring reserve, recorded in Accrued restructuring	$ 362,000,000	$ 654,000,000