Discontinued Operations - Schedule of Discontinued Operations, Financial Results (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2018	Jul. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net loss from discontinued operations	$ (1)	$ (120)	$ (119)	$ (238)
Separation and merger transactions | Discontinued Operations, Disposed of by Means Other than Sale, Spinoff
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net revenue	0	708	0	8,337
Cost of revenue	0	218	0	5,838
Expenses	0	647	51	2,888
Interest and other, net	0	10	68	13
Loss from discontinued operations before taxes	0	(167)	(119)	(402)
(Provision) benefit for taxes	(1)	47	0	164
Net loss from discontinued operations	$ (1)	$ (120)	$ (119)	$ (238)