Summary of Significant Accounting Policies - Narrative (Details) $ in Millions	3 Months Ended
	Jan. 31, 2020 USD ($) segments	Jan. 31, 2019 USD ($)	Oct. 31, 2019 USD ($)	Jul. 31, 2019 USD ($) employees	Nov. 01, 2018 USD ($)
Accounting Policies [Line Items]
Document Period End Date	Jan. 31, 2020
Cumulative Effect of New Accounting Principle in Period of Adoption					$ (27)
Selling, General and Administrative Expense	$ (182)	$ (186)
Net Cash Provided by (Used in) Investing Activities	(54)	74
Sales of Manufactured Products	1,794	2,386
Accounts Receivable, Net, Current	(269)		$ (338)
Property and equipment, net	(1,283)		(1,309)
Liabilities, Current	(3,031)		(3,575)
Long-term Debt and Capital Lease Obligations	(4,283)		(4,317)
Other Liabilities, Noncurrent	732		645
Liabilities	(10,102)		(10,640)
Assets	(6,363)		(6,917)
Debt, Current	(452)		(871)
Other Liabilities, Current	1,293		1,363
Cost of Goods and Services Sold	$ (1,529)	(1,979)
Number Of Segments | segments	4
Goodwill	$ 38		38
Interest expense	(65)	(85)
Income (Loss) Attributable to Parent, before Tax	(37)	(2)
Capital expenditures	59	44
Proceeds from finance lease obligations	0	6
Product Warranty Accrual, Preexisting, Increase (Decrease)	$ 4	(7)
Document Type	10-Q
Inventory, Gross			200	$ 253
Tax expense	$ 5	19
Stockholders' Equity Attributable to Parent	(3,741)		(3,726)
Inventory, Net	(1,074)		(911)	$ (1,074)
Other Assets, Current	279		277
Assets, Current	4,287		4,952
Deferred Tax Assets, Net of Valuation Allowance, Noncurrent	(127)		(117)
Other Assets, Noncurrent	(103)		(107)
Liabilities and Equity	(6,363)		(6,917)
Other Operating Income (Expense), Net	(11)	(97)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(32)	17
Unionized Employees Concentration Risk [Member] | Number Of Employees Hourly Workers [Member]
Accounting Policies [Line Items]
Concentration Risk Number Of Employees | employees				7,200
concentration risk number of employees percentage				99.00%
Unionized Employees Concentration Risk [Member] | Number of Employees Salaried Workers [Member]
Accounting Policies [Line Items]
Concentration Risk Number Of Employees | employees				700
concentration risk number of employees percentage				13.00%
Traton Group [Member]
Accounting Policies [Line Items]
Less: Intercompany revenues	31	29
Costs and Expenses, Related Party	17	13
Accounts Receivable, Related Parties			13	$ 17
Accounts Payable, Related Parties			55	69
Navistar Defense [Member]
Accounting Policies [Line Items]
Less: Intercompany revenues	14	6
Accounts Receivable, Related Parties			29	$ 27
North America Truck [Member]
Accounting Policies [Line Items]
Assets	(1,844)		$ (1,705)
Interest expense	0	0
Capital expenditures	47	31
Tax expense	$ 0	0
Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations [Member]
Accounting Policies [Line Items]
Extended Product Warranty Accrual		$ 2