Taxes on Earnings (Details) $ in Millions	3 Months Ended		12 Months Ended
	Jan. 31, 2017 USD ($) country	Jan. 31, 2016 USD ($)	Oct. 31, 2016 USD ($)	Oct. 31, 2015
Differences between the U.S. federal statutory income tax rate and HP's effective tax rate
Effective tax rate (as a percent)	22.60%	16.30%
U.S. federal statutory income tax rate (as a percent)	35.00%
Net income tax charges (benefits) related to discrete items	$ (108)	$ (110)
Other benefits	138	$ 104
Income tax charges for various prior period adjustments	$ 19
Number of countries other than the United States where the entity is subject to income tax | country	110
Unrecognized tax benefits	$ 11,700		$ 11,600
Unrecognized tax benefits that would affect effective tax rate if realized			3,100
Accrued income tax for interest and penalties	$ 426		423
Likelihood of no resolution period	12 months
Reasonably possible reduction in existing unrecognized tax benefits within the next 12 months	$ 2,700
Likelihood of conclusion period for certain federal, foreign and state tax issues	12 months
Deferred tax assets - long-term	$ 4,477		4,430
Deferred tax liabilities - long-term	(140)		(143)
Deferred tax assets net of deferred tax liabilities	4,337		4,287
Advance royalty proceeds received from multi-year intercompany licensing arrangements	$ 439		$ 3,700
Royalty recognition term				5 years