Taxes on Earnings (Details 4) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Oct. 31, 2011	Oct. 31, 2010	Oct. 31, 2009
Differences between the U.S. federal statutory income tax rate and HP's effective tax rate
U.S. federal statutory income tax rate (as a percent)	35.00%	35.00%	35.00%
State income taxes, net of federal tax benefit (as a percent)	0.50%	1.30%	0.90%
Lower rates in other jurisdictions, net (as a percent)	(24.00%)	(18.30%)	(12.20%)
Research and development credit (as a percent)	(0.60%)	(0.10%)	(0.50%)
Foreign net operating loss (as a percent)			(4.10%)
Valuation allowance (as a percent)	5.20%	0.80%	(0.60%)
Accrued taxes due to post acquisition integration (as a percent)			0.60%
Nondeductible goodwill (as a percent)	3.40%
Other, net (as a percent)	1.70%	1.50%	(0.50%)
Effective income tax rate (as a percent)	21.20%	20.20%	18.60%
Income tax expense (benefit) related to items unique to the year	$ 325	$ (26)	$ (547)
Income tax benefits for adjustments to prior year foreign income tax accruals or net deferred tax assets for foreign net operating loss	78		383
Income tax benefit, prior period liability	63		154
Tax charges for increases to foreign and state valuation allowances or valuation allowance reversals	468		(60)
Net tax charge (benefit) associated with miscellaneous prior period items	(2)		50
Income tax benefits, reduced rates for subsidiaries in certain countries	$ 1,300	$ 966	$ 853
Income tax benefits, reduced rates for subsidiaries in certain countries (in basic earnings dollars per share)	$ 0.62	$ 0.41	$ 0.35