Common Merger Consideration Price, Canceled or Converted

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Equity Interest, Percent Sold

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Amount for accounts payable to related parties.

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For an unclassified balance sheet, amount of receivables arising from transactions with related parties.

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Face amount or stated value per share of common stock.

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Costs of sales and operating expenses for the period incurred from transactions with related parties.

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.

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Summary of Significant Accounting Policies - Related Party Transactions (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended
	Dec. 31, 2018	Apr. 30, 2021	Apr. 30, 2020	Apr. 30, 2021	Apr. 30, 2020	Oct. 31, 2020
Related Party Transaction [Line Items]
Common stock, par value (in dollars per share)		$ 0.10		$ 0.10		$ 0.10
Common merger consideration price, canceled or converted (in dollars per share)				$ 44.50
Navistar Defense
Related Party Transaction [Line Items]
Ownership percentage		30.00%		30.00%
Traton Group
Related Party Transaction [Line Items]
Revenue recognized		$ 60	$ 12	$ 110	$ 43
Net expense incurred		15	7	39	24
Accounts receivable		10		10		$ 18
Accounts payable		111		111		90
Navistar Defense
Related Party Transaction [Line Items]
Revenue recognized		4	$ 11	8	$ 25
Accounts receivable		$ 10		$ 10		$ 8
Equity interest percentage	70.00%
Series D Stock
Related Party Transaction [Line Items]
Preferred stock, par value (in dollars per share)		$ 1.00		$ 1.00
Series B Stock
Related Party Transaction [Line Items]
Preferred stock, par value (in dollars per share)		$ 1.00		$ 1.00