Taxes on Earnings (Detail 4) $ in Millions	12 Months Ended
	Oct. 31, 2017 USD ($) country	Oct. 31, 2016 USD ($)	Oct. 31, 2015 USD ($)
Reconciliation of unrecognized tax benefits
Balance at beginning of year	$ 11,411	$ 4,901	$ 1,024
Increases:
For current year's tax positions	28	1,456	1,428
For prior years' tax positions	311	820	3,538
Net transfers from former Parent through equity	0	4,455	0
Decreases:
For prior years' tax positions	(202)	(114)	(70)
Statute of limitations expiration	(70)	(47)	(2)
Settlements with taxing authorities	(216)	(60)	(7)
Net transfers to former Parent through equity	0	0	(1,010)
Balance at end of year	11,262	11,411	4,901
Unrecognized tax benefits that would affect effective tax rate if realized	3,000	2,700	$ 200
Increase in unrecognized tax benefit related to the timing of intercompany royalty income recognition	149
Increase in unrecognized tax benefits		6,500
Accrued income tax for interest and penalties	$ 304	$ 197
Likelihood of no resolution period	12 months
Likelihood of conclusion period for certain federal, foreign and state tax issues	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	120
Income tax examination, proposed assessment amount	$ 456
Undistributed earnings from non-U.S. operations	$ 12,000