Income Taxes (Details) (USD $)	3 Months Ended		70 Months Ended
	Jan. 31, 2012 M country	Jan. 31, 2011	Aug. 26, 2008	Oct. 31, 2011
Income Taxes
Effective tax rate (as a percent)	19.40%	21.00%
U.S. federal statutory income tax rate (as a percent)	35.00%
Tax benefits resulting from reconciling items	$ 49,000,000	$ 101,000,000
Tax benefits from restructuring and acquisition charges	28,000,000	58,000,000
Net income tax benefit from reversals of accrued interest expense and penalties on uncertain tax positions, net of tax	23,000,000
Tax benefit from the retroactive research and development credit		43,000,000
Unrecognized tax benefits	2,300,000,000
Unrecognized tax benefits that would affect effective tax rate if realized	1,100,000,000
Accrued income tax payable for interest and penalties	182,000,000
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	238,000,000
Number of foreign countries in which HP is subject to income taxes	80
Income tax examination, reduction in tax benefits	558,000,000
Income tax examination, additional tax payable			320,000,000
Classification of current and long-term deferred tax assets and liabilities
Current deferred tax assets	4,857,000,000			5,374,000,000
Current deferred tax liabilities	(29,000,000)			(41,000,000)
Long-term deferred tax assets	1,439,000,000			1,283,000,000
Long-term deferred tax liabilities	(4,992,000,000)			(5,163,000,000)
Total deferred tax assets net of deferred tax liabilities	$ 1,275,000,000			$ 1,453,000,000