Taxes on Earnings - Uncertain Tax Positions (Narrative) (Details) $ in Millions	12 Months Ended
	Oct. 31, 2017 USD ($) country	Oct. 31, 2016 USD ($)	Oct. 31, 2015 USD ($)	Oct. 31, 2014 USD ($)
Income Tax Disclosure [Abstract]
Unrecognized tax benefits	$ 10,808	$ 10,858	$ 6,546	$ 1,545
Unrecognized tax benefits that would affect effective tax rate if realized	3,900	$ 3,900
Accrued income tax for interest and penalties	$ 257
Likelihood of no resolution period	12 months
Conclusion of federal, foreign and state tax issues, period	12 months
Reasonably possible decrease in existing unrecognized tax benefits within the next 12 months	$ 2,700
Number of other countries in which HP is subject to income taxes | country	58
Income tax examination, reduction in tax benefits	$ 377
Undistributed earnings from non-U.S. operations	$ 21,700