Discontinued Operations - Schedule of Discontinued Operations, Financial Results (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net loss from discontinued operations	$ (92)	$ (76)	$ (179)
Everett SpinCo, Inc. and Seattle SpinCo, Inc. | Spinoff
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net revenue	8,511	19,843	21,030
Cost of revenue	5,890	15,000	16,155
Expenses	3,063	4,596	5,298
Interest and other, net	39	28	42
(Loss) earnings from discontinued operations before taxes	(481)	219	(465)
Benefit (provision) for taxes	389	(295)	286
Net loss from discontinued operations	$ (92)	$ (76)	$ (179)