Summary of Significant Accounting Policies Related Party Transactions (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018	Oct. 31, 2018
Traton Group [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	$ 42	$ 33	$ 113	$ 114
Costs and Expenses, Related Party	11	$ 2	29	$ 21
Accounts Receivable, Related Parties	16		16		$ 10
Accounts Payable, Related Parties	48		48		$ 25
Navistar Defense [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	9		43
Accounts Receivable, Related Parties	$ 29		$ 29

Amount for accounts payable to related parties.

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