Fair Value Measurements - Narrative (Details) - USD ($) $ in Millions	3 Months Ended				12 Months Ended
	Oct. 31, 2016	Jul. 31, 2016	Jul. 31, 2015	Apr. 30, 2014	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2014	Oct. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset impairment charges					$ 27	$ 30	$ 183
Goodwill	$ 38				38	38	38	$ 184
Cash and Cash Equivalents, Maturity Term	90 days
Marketable Securities, Maturity Term	90 days
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)					1	7	7
Brazilian Reporting Unit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Indefinite-Lived Intangible Assets (Excluding Goodwill)			$ 24	$ 43
Goodwill				142
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)		$ 1	$ 3	$ 7
North America Truck [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset impairment charges					17	11	33
Goodwill	$ 0				0	0	$ 0	$ 0
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)					$ 8	$ 9