Summary of Significant Accounting Policies - Narrative (Details) $ in Millions	3 Months Ended				6 Months Ended
	Apr. 30, 2020 USD ($) employees segments	Jan. 31, 2020 USD ($)	Apr. 30, 2019 USD ($)	Jan. 31, 2019 USD ($)	Apr. 30, 2020 USD ($) employees segments	Apr. 30, 2019 USD ($)	Oct. 31, 2019 USD ($)	Nov. 01, 2018 USD ($)
Accounting Policies [Line Items]
Document Period End Date					Apr. 30, 2020
Cumulative Effect of New Accounting Principle in Period of Adoption								$ (27)
Selling, General and Administrative Expense	$ (170)		$ (373)		$ (352)	$ (559)
Net Cash Provided by (Used in) Investing Activities					(89)	37
Sales of Manufactured Products	1,877		2,948		3,671	5,334
Accounts Receivable, Net, Current	(225)				(225)		$ (338)
Property and equipment, net	(1,207)				(1,207)		(1,309)
Liabilities, Current	(2,683)				(2,683)		(3,575)
Long-term Debt and Capital Lease Obligations	(4,859)				(4,859)		(4,317)
Other Liabilities, Noncurrent	722				722		645
Liabilities	(10,296)				(10,296)		(10,640)
Assets	(6,440)	$ (6,440)			(6,440)		(6,917)
Debt, Current	(570)				(570)		(871)
Other Liabilities, Current	1,075				1,075		1,363
Cost of Goods and Services Sold	$ (1,624)		(2,493)		$ (3,153)	(4,472)
Number Of Segments | segments	4				4
Goodwill	$ 38				$ 38		38
Interest expense	(63)		(82)		(128)	(167)
Income (Loss) Attributable to Parent, before Tax	(26)		(44)		(63)	(46)
Capital expenditures	31		22		90	66
Proceeds from finance lease obligations					0	9
Product Warranty Accrual, Preexisting, Increase (Decrease)					$ 17	2
Document Type					10-Q
Inventory, Gross	232				$ 232		200
Tax expense	(7)		1		(2)	20
Stockholders' Equity Attributable to Parent	(3,858)				(3,858)		(3,726)
Inventory, Net	(1,012)				(1,012)		(911)
Other Assets, Current	265				265		277
Assets, Current	4,525				4,525		4,952
Other Assets, Noncurrent	(102)				(102)		(107)
Liabilities and Equity	(6,440)				(6,440)		(6,917)
Other expense, net	2		18		13	115
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ (33)	$ (32)	(43)	$ 17	$ (65)	(26)
Unionized Employees Concentration Risk [Member] | Number Of Employees Hourly Workers [Member]
Accounting Policies [Line Items]
Concentration Risk Number Of Employees | employees	7,100				7,100
concentration risk number of employees percentage	99.00%				99.00%
Unionized Employees Concentration Risk [Member] | Number of Employees Salaried Workers [Member]
Accounting Policies [Line Items]
Concentration Risk Number Of Employees | employees	700				700
concentration risk number of employees percentage	13.00%				13.00%
Traton Group [Member]
Accounting Policies [Line Items]
Less: Intercompany revenues	$ 12		42		$ 43	71
Costs and Expenses, Related Party	7		5		24	18
Accounts Receivable, Related Parties	4				4		13
Accounts Payable, Related Parties	75				75		55
Navistar Defense [Member]
Accounting Policies [Line Items]
Less: Intercompany revenues	11		28		25	34
Accounts Receivable, Related Parties	27				27		29
North America Truck [Member]
Accounting Policies [Line Items]
Assets	(1,840)				(1,840)		$ (1,705)
Interest expense	0		0		0	0
Capital expenditures	28		21		75	52
Tax expense	$ 0		$ 0		$ 0	$ 0