Income Taxes (Details) (USD $)	3 Months Ended			9 Months Ended		12 Months Ended	70 Months Ended
	Jul. 31, 2012 country	Jul. 31, 2011	Jan. 31, 2011	Jul. 31, 2012 M country	Jul. 31, 2011	Oct. 31, 2008	Aug. 31, 2008	Oct. 31, 2011
Income Taxes
Effective tax rate (as a percent)	2.20%	19.70%		(10.30%)	20.40%
U.S. federal statutory income tax rate (as a percent)				35.00%
Tax benefits resulting from reconciling items	$ 670,000,000	$ 145,000,000		$ 744,000,000	$ 302,000,000
Tax benefits from restructuring and acquisition charges	564,000,000	62,000,000		614,000,000	174,000,000
Discrete income tax charge to record valuation allowances on certain deferred tax assets related to the Services segment	823,000,000			823,000,000
Tax benefits from reversals of deferred income tax liabilities on foreign earnings	827,000,000			827,000,000
Tax benefits from miscellaneous discrete items	102,000,000			126,000,000
Tax benefits from settlement of tax audit matters and other miscellaneous items		83,000,000			85,000,000
Tax benefit from the retroactive research and development credit			43,000,000
Unrecognized tax benefits	2,700,000,000			2,700,000,000
Unrecognized tax benefits that would affect effective tax rate if realized	1,100,000,000			1,100,000,000
Accrued income tax payable for interest and penalties	196,000,000			196,000,000
Net interest expense on net tax underpayments, net of tax	9,000,000			9,000,000
Net interest income on net tax overpayments, net of tax				10,000,000
Income tax examination, likelihood of no resolution period (in months)				12
Income tax examination, likelihood of conclusion period (in months)				12
Reasonably possible, reduction in existing unrecognized tax benefits within the next 12 months	235,000,000			235,000,000
Number of foreign countries in which HP is subject to income taxes	80			80
Income tax examination, reduction in tax benefits				626,000,000
Income tax examination, additional tax payable						17,000,000	320,000,000
Classification of current and long-term deferred tax assets and liabilities
Current deferred tax assets	4,614,000,000			4,614,000,000				5,374,000,000
Current deferred tax liabilities	(86,000,000)			(86,000,000)				(41,000,000)
Long-term deferred tax assets	1,176,000,000			1,176,000,000				1,283,000,000
Long-term deferred tax liabilities	(3,920,000,000)			(3,920,000,000)				(5,163,000,000)
Total deferred tax assets net of deferred tax liabilities	$ 1,784,000,000			$ 1,784,000,000				$ 1,453,000,000