Equity Method Investments (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017	May 31, 2016
Schedule of Equity Method Investments [Line Items]
Investments in equity interests	$ 2,254	$ 2,398
Earnings (loss) from equity interests	20	38	$ (23)
Equity Method Investee | H3C
Schedule of Equity Method Investments [Line Items]
Sales to related party	897	1,300	1,200
Purchases from related party	202	273	331
Payable to H3C	39	43
Receivables due from H3C	32	10
H3C
Schedule of Equity Method Investments [Line Items]
Investments in equity interests	$ 2,300	2,400
Ownership	49.00%
Cash dividend	$ 156	164
Basis difference				$ 2,534
Equity method goodwill				1,674
Intangible assets				749
In-process research and development				188
Deferred tax liabilities				(152)
Other				$ 75
Weighted-average useful life	5 years
Earnings (loss) from equity interests	$ 20	38	(23)
Investment's earnings	167	192	127
Amortization of difference in basis	(152)	(151)	(155)
Elimination of intra-entity sales	$ 5	$ (3)	$ 5