Supplementary Financial Information - Interest and Other, Net (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Tax indemnifications	$ (784)	$ (3)	$ (769)	$ (676)
Loss on extinguishment of debt	0	0	0	(126)
Interest expense on borrowings	(57)	(66)	(182)	(241)
Other, net	10	69	49	212
Interest and other, net	(831)	$ 0	(902)	(831)
Change in Tax Indemnification	$ 764		$ 764	$ 676