Fair Value Measurements - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2018	Oct. 31, 2017	Oct. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset impairment charges	$ 14	$ 13	$ 27
Goodwill	$ 38	$ 38
Cash and Cash Equivalents, Maturity Term	90 days
Marketable Securities, Maturity Term	90 days