Restructuring Charges (Details) (USD $)	3 Months Ended		9 Months Ended			3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	1 Months Ended	3 Months Ended	9 Months Ended	1 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended		1 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended		3 Months Ended	9 Months Ended	12 Months Ended	3 Months Ended	9 Months Ended	1 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended		9 Months Ended	1 Months Ended	9 Months Ended		1 Months Ended	3 Months Ended	9 Months Ended	1 Months Ended	9 Months Ended		3 Months Ended	9 Months Ended
	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2012	Jul. 31, 2011	Oct. 31, 2011	Jul. 31, 2012 U.S. Defined Benefit Plans	Jul. 31, 2012 U.S. Defined Benefit Plans	Jul. 31, 2012 Post-Retirement Benefit Plans	Jul. 31, 2012 Post-Retirement Benefit Plans	May 31, 2012 Fiscal 2012 Restructuring Plan position	Jul. 31, 2012 Fiscal 2012 Restructuring Plan position	Jul. 31, 2012 Fiscal 2012 Restructuring Plan position	May 31, 2012 Fiscal 2012 Restructuring Plan Severance and EER	Jul. 31, 2012 Fiscal 2012 Restructuring Plan Severance and EER	Jul. 31, 2012 Fiscal 2012 Restructuring Plan Severance and EER	Jul. 31, 2012 Fiscal 2012 Restructuring Plan Severance and EER U.S. Defined Benefit Plans	Jul. 31, 2012 Fiscal 2012 Restructuring Plan Severance and EER Retirement medical savings account	May 31, 2012 Fiscal 2012 Restructuring Plan Infrastructure and other items	Jul. 31, 2012 Fiscal 2012 Restructuring Plan Infrastructure and other items	Jul. 31, 2012 Fiscal 2012 Restructuring Plan Infrastructure and other items	Jul. 31, 2012 2012 EER	Jul. 31, 2012 2012 EER	Jul. 31, 2012 2012 EER Retirement medical savings account	Jul. 31, 2012 2012 EER Special Termination Benefit	Jul. 31, 2012 Fiscal 2010 Acquisitions	Oct. 31, 2011 Fiscal 2010 Acquisitions	Jul. 31, 2012 Fiscal 2010 Enterprise Services Business Restructuring Plan	Jul. 31, 2012 Fiscal 2010 Enterprise Services Business Restructuring Plan	Jun. 30, 2010 Fiscal 2010 Enterprise Services Business Restructuring Plan Severance and workforce reductions position	Jan. 31, 2012 Fiscal 2010 Enterprise Services Business Restructuring Plan Severance and workforce reductions	Jul. 31, 2012 Fiscal 2010 Enterprise Services Business Restructuring Plan Severance and workforce reductions position	Jul. 31, 2012 Fiscal 2010 Enterprise Services Business Restructuring Plan Infrastructure	Jan. 31, 2012 Fiscal 2010 Enterprise Services Business Restructuring Plan Infrastructure	Jul. 31, 2012 Fiscal 2010 Enterprise Services Business Restructuring Plan Infrastructure	May 31, 2009 Fiscal 2009 Restructuring Plan position	Jul. 31, 2012 Fiscal 2009 Restructuring Plan	Oct. 31, 2011 Fiscal 2009 Restructuring Plan position	Aug. 31, 2008 Fiscal 2008 HP/EDS Restructuring Plan	Jul. 31, 2012 Fiscal 2008 HP/EDS Restructuring Plan	Jul. 31, 2012 Fiscal 2008 HP/EDS Restructuring Plan	Aug. 31, 2008 Fiscal 2008 HP/EDS Restructuring Plan Severance and workforce reductions position	Jul. 31, 2012 Fiscal 2008 HP/EDS Restructuring Plan Severance and workforce reductions	Oct. 31, 2011 Fiscal 2008 HP/EDS Restructuring Plan Severance and workforce reductions position	Jul. 31, 2012 Fiscal 2008 HP/EDS Restructuring Plan Infrastructure	Jul. 31, 2012 Fiscal 2008 HP/EDS Restructuring Plan Infrastructure
Restructuring and related costs
Expected positions to be eliminated										29,000																			8,000						4,400						25,000
Positions eliminated											3,800	3,800																			7,300						4,400						25,000
Net restructuring charge	$ 1,795,000,000	$ 150,000,000	$ 1,888,000,000	$ 466,000,000
Severance and benefits																					1,700,000,000
Stock-based compensation expense																					41,000,000
Additional restructuring costs																										33,000,000
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	493,000,000		3,000,000	3,000,000						258,000,000					258,000,000
Charges	1,795,000,000		1,888,000,000								1,732,000,000	1,732,000,000		1,680,000,000	1,680,000,000				52,000,000	52,000,000							33,000,000	72,000,000		(100,000,000)	(100,000,000)	33,000,000	104,000,000	172,000,000		7,000,000			30,000,000	77,000,000		5,000,000		30,000,000	72,000,000
Asset impairment charges																				45,000,000
Cash payments			(472,000,000)									(82,000,000)			(81,000,000)					(1,000,000)					(19,000,000)			(248,000,000)			(111,000,000)			(137,000,000)		(9,000,000)				(114,000,000)		(7,000,000)			(107,000,000)
Special Termination Benefits-expected cash payment																								53,000,000
Other adjustments and non-cash settlements			(1,224,000,000)									(1,152,000,000)			(1,106,000,000)					(46,000,000)					(1,000,000)			(64,000,000)			(27,000,000)			(37,000,000)		2,000,000				(9,000,000)		2,000,000			(11,000,000)
Balance at the end of the period	1,005,000,000		1,005,000,000								498,000,000	498,000,000		493,000,000	493,000,000				5,000,000	5,000,000					39,000,000	59,000,000	256,000,000	256,000,000			255,000,000	1,000,000		1,000,000					212,000,000	212,000,000				212,000,000	212,000,000
Total costs and adjustments to date			6,376,000,000									1,732,000,000			1,680,000,000					52,000,000					114,000,000			988,000,000			623,000,000			365,000,000		301,000,000				3,241,000,000		2,195,000,000			1,046,000,000
Total expected costs and adjustments			8,377,000,000									3,683,000,000			3,279,000,000					404,000,000					121,000,000	121,000,000		992,000,000			623,000,000			369,000,000		301,000,000				3,280,000,000		2,195,000,000			1,085,000,000
Special termination benefits						(833,000,000)	(833,000,000)	(227,000,000)	(227,000,000)							833,000,000	227,000,000				(833,000,000)	(833,000,000)	(227,000,000)
Long-term portion of restructuring reserve, recorded in Other liabilities	263,000,000		263,000,000		159,000,000
Expected cost of the plan										3,700,000,000			3,300,000,000					400,000,000											1,000,000,000						301,000,000			3,300,000,000
Short-term portion of restructuring reserve, recorded in Accrued restructuring	$ 742,000,000		$ 742,000,000		$ 654,000,000