Retirement and Post-Retirement Benefit Plans - Defined Benefit Plans (Narrative) (Details) - USD ($) $ in Millions	Oct. 31, 2018	Oct. 31, 2017
DPSP
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	$ 536	$ 580

Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits under both defined benefit and deferred profit sharing plans, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those non-benefit obligations may be considered as reductions of plan assets.

No definition available.

Name:	hpq_DefinedContributionPlanandDeferredProfitSharingPlanFairValueofPlanAssets
Namespace Prefix:	hpq_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant