Debt - Narrative (Details)	1 Months Ended			3 Months Ended				12 Months Ended
	Oct. 31, 2020 USD ($)	Oct. 31, 2019 USD ($)	May 31, 2019 USD ($)	Oct. 31, 2019 USD ($)	Jan. 31, 2019 USD ($)	Jan. 31, 2018 USD ($)	Apr. 30, 2014 USD ($)	Oct. 31, 2020 USD ($) $ / shares	Oct. 31, 2019 USD ($)	Oct. 31, 2018 USD ($)	Jun. 30, 2019 USD ($)	Apr. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Sep. 30, 2018 USD ($)	Jul. 31, 2018 USD ($)	Jul. 31, 2017 USD ($)	Feb. 28, 2017 USD ($)	Dec. 31, 2016 USD ($)	Jan. 31, 2015 USD ($)	Apr. 30, 2013	Aug. 31, 2012 USD ($)
Debt Instrument [Line Items]
Debt Instrument, Coupon Rate, Increase (Decrease)					0.0675	0.0650
Long-Term Debt, Maturity, Year One	$ 640,000,000							$ 640,000,000
Amortization								0	$ 0	$ 2,000,000
Line of Credit Facility, Increase (Decrease) for Period, Description					$ 1,700,000,000
Debt Instrument, Unamortized Discount	43,000,000							43,000,000
Payments of Debt Issuance Costs								18,000,000	9,000,000	41,000,000
Long-term Debt	5,330,000,000							5,330,000,000
Proceeds from issuance of securitized debt								389,000,000	363,000,000	339,000,000
Long-Term Debt, Maturity, Year Two	460,000,000							460,000,000
Long-Term Debt, Maturity, Year Three	238,000,000							238,000,000
Long-Term Debt, Maturity, Year Four	615,000,000							615,000,000
Long-Term Debt, Maturity, Year Five	619,000,000							619,000,000
Long-term Debt, Maturities, Repayments of Principal in Rolling after Year Five	2,801,000,000							2,801,000,000
Long-term Debt, Gross	5,373,000,000							5,373,000,000
Payments to subsidiary to meet convenant requirement								0	0	0
Payments of Dividends	30,000,000	$ 20,000,000
Write-off of debt issuance cost and discount								$ 5,000,000	6,000,000	43,000,000
Four Point Seven Five Senior Subordinated Convertible Notes [Member] [Member]
Debt Instrument [Line Items]
Debt Instrument, Convertible, Conversion Ratio				18.4946
Option Indexed to Issuer's Equity, Strike Price | $ / shares								$ 54.07
Manufacturing Operations [Member]
Debt Instrument [Line Items]
Long-Term Debt, Maturity, Year One	45,000,000							$ 45,000,000
Debt Instrument, Unamortized Discount	39,000,000							39,000,000
Long-term Debt	3,496,000,000							3,496,000,000
Long-Term Debt, Maturity, Year Two	28,000,000							28,000,000
Long-Term Debt, Maturity, Year Three	27,000,000							27,000,000
Long-Term Debt, Maturity, Year Four	18,000,000							18,000,000
Long-Term Debt, Maturity, Year Five	616,000,000							616,000,000
Long-term Debt, Maturities, Repayments of Principal in Rolling after Year Five	2,801,000,000							2,801,000,000
Long-term Debt, Gross	3,535,000,000							3,535,000,000
Financial Services Operations
Debt Instrument [Line Items]
Long-Term Debt, Maturity, Year One	595,000,000							595,000,000
Pledged Assets, Other, Not Separately Reported on Statement of Financial Position		1,100,000,000		$ 1,100,000,000					1,100,000,000	1,300,000,000
Debt Instrument, Unamortized Discount	4,000,000							4,000,000
Long-term Debt	1,834,000,000							1,834,000,000
Long-Term Debt, Maturity, Year Two	432,000,000							432,000,000
Long-Term Debt, Maturity, Year Three	211,000,000							211,000,000
Long-Term Debt, Maturity, Year Four	597,000,000							597,000,000
Long-Term Debt, Maturity, Year Five	3,000,000							3,000,000
Long-term Debt, Maturities, Repayments of Principal in Rolling after Year Five	0							0
Long-term Debt, Gross	1,838,000,000							1,838,000,000
Financial Services Operations | Trac Funding Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		200,000,000		200,000,000					200,000,000			$ 150,000,000	$ 100,000,000
Repayments of Long-term Lines of Credit								334,000,000	743,000,000	336,000,000
Debt Instrument, Increase (Decrease), Net								294,000,000	800,000,000	336,000,000
Financial Services Operations | VFN Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	300,000,000	1,495,000,000		1,495,000,000		$ 350,000,000		300,000,000	1,495,000,000	590,000,000	$ 350,000,000	$ 550,000,000
Repayments of Long-term Lines of Credit								515,000,000	1,540,000,000	455,000,000
Debt Instrument, Face Amount						425,000,000
Financial Services Operations | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity						100,000,000
Revolving Credit Facility [Member] | Financial Services Operations | Bank Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	538,000,000	623,000,000	$ 748,000,000	623,000,000				538,000,000	623,000,000						$ 269,000,000			$ 275,000,000
Term Loan [Member] | Manufacturing Operations [Member]
Debt Instrument [Line Items]
Long-term Line of Credit						1,600,000,000
Amortization					4,000,000
Extinguishment of Debt, Amount						16,000,000
Long-term Debt	1,543,000,000	1,556,000,000		1,556,000,000				1,543,000,000	1,556,000,000
Write-off of debt issuance cost and discount								5,000,000
Term Loan [Member] | Financial Services Operations
Debt Instrument [Line Items]
Long-term Debt			398,000,000
Write-off of debt issuance cost and discount			$ 6,000,000
Asset-Based Credit Facility [Member]
Debt Instrument [Line Items]
Repayments of Long-term Lines of Credit								60,000,000
Line of Credit Facility, Current Borrowing Capacity										125,000,000
Debt Instrument, Liquidity Block																					$ 13,000,000
Long-term Line of Credit	0							0		0
Proceeds from Lines of Credit								60,000,000
Line of Credit [Member] | Manufacturing Operations [Member]
Debt Instrument [Line Items]
Debt Instrument, Unamortized Discount		0		0					0	7,000,000
Debt Issuance Costs, Net		0		0					0	9,000,000
Line of Credit [Member] | Financial Services Operations
Debt Instrument [Line Items]
Debt Issuance Costs, Net		2,000,000		2,000,000					2,000,000	$ 2,000,000
Long-term Debt	940,000,000	1,059,000,000		1,059,000,000				940,000,000	1,059,000,000
Notes Payable to Banks [Member] | Manufacturing Operations [Member]
Debt Instrument [Line Items]
Extinguishment of Debt, Amount						30,000,000
Long-term Debt	$ 1,087,000,000	$ 1,085,000,000		$ 1,085,000,000				$ 1,087,000,000	$ 1,085,000,000
Notes Issued					$ 1,100,000,000	$ 1,450,000,000
Notes Payable to Banks [Member] | Manufacturing Operations [Member] | Six Point Six Two Five Senior Subordinated Convertible Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		6.625%		6.625%					6.625%	6.625%
Notes Payable to Banks [Member] | Manufacturing Operations [Member] | Eight Point Two Five Percent Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Unamortized Discount		$ 0		$ 0					$ 0	$ 13,000,000
Debt Issuance Costs, Net		$ 0		$ 0					$ 0	14,000,000
Debt Instrument, Interest Rate, Stated Percentage		8.25%		8.25%					8.25%
Convertible Subordinated Debt [Member] | Four Point Seven Five Senior Subordinated Convertible Notes [Member] [Member]
Debt Instrument [Line Items]
Debt Instrument, Unamortized Discount		$ 1,000,000		$ 1,000,000					$ 1,000,000
Convertible Subordinated Debt [Member] | Manufacturing Operations [Member] | Six Point Six Two Five Senior Subordinated Convertible Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.625%							6.625%
Convertible Subordinated Debt [Member] | Manufacturing Operations [Member] | Four Point Five Zero Senior Subordinated Convertible Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Unamortized Discount		0		0					0	5,000,000
Debt Issuance Costs, Net		$ 0		$ 0					$ 0	$ 1,000,000
Debt Instrument, Interest Rate, Stated Percentage		4.50%		4.50%					4.50%	4.75%
Long-term Debt, Fair Value							$ 177,000,000
Convertible Subordinated Debt [Member] | Manufacturing Operations [Member] | Four Point Seven Five Senior Subordinated Convertible Notes [Member] [Member]
Debt Instrument [Line Items]
Debt Instrument, Unamortized Discount		$ 5,000,000		$ 5,000,000					$ 5,000,000	$ 14,000,000
Debt Issuance Costs, Net		$ 1,000,000		$ 1,000,000					$ 1,000,000	3,000,000
Debt Instrument, Interest Rate, Stated Percentage		4.75%		4.75%					4.75%
Long-term Debt, Fair Value							367,000,000
Debt Instrument, Convertible, Carrying Amount of Equity Component		$ 44,000,000		$ 44,000,000			22,000,000		$ 44,000,000
Notes Payable, Other Payables [Member] | Manufacturing Operations [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 9,000,000	11,000,000		11,000,000				$ 9,000,000	11,000,000
Notes Payable, Other Payables [Member] | Financial Services Operations
Debt Instrument [Line Items]
Debt Instrument, Face Amount		300,000,000		300,000,000					300,000,000					$ 300,000,000		$ 250,000,000
Tax Exempt Bond [Member] | Manufacturing Operations [Member]
Debt Instrument [Line Items]
Debt Issuance Costs, Net		$ 5,000,000		$ 5,000,000					$ 5,000,000	$ 5,000,000
Debt Instrument, Interest Rate, Stated Percentage		6.75%		6.75%					6.75%	6.75%
Long-term Debt	0	$ 220,000,000		$ 220,000,000				0	$ 220,000,000
Secured Debt [Member] | Financial Services Operations
Debt Instrument [Line Items]
Debt Issuance Costs, Net		4,000,000		4,000,000					4,000,000	$ 5,000,000
Long-term Debt	724,000,000	991,000,000		991,000,000				724,000,000	991,000,000
Base Rate [Member] | Term Loan [Member] | Manufacturing Operations [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate						2.50%
Eurodollar [Member] | Term Loan [Member] | Manufacturing Operations [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate						3.50%
Additional Paid-in Capital | Convertible Subordinated Debt [Member] | Manufacturing Operations [Member] | Four Point Seven Five Senior Subordinated Convertible Notes [Member] [Member]
Debt Instrument [Line Items]
Debt Related Commitment Fees and Debt Issuance Costs							$ 1,000,000
United States Dollars and Mexican Pesos [Member] | Financial Services Operations
Debt Instrument [Line Items]
Long-term Debt	$ 402,000,000	437,000,000		437,000,000				$ 402,000,000	437,000,000
Mexico, Pesos
Debt Instrument [Line Items]
Commercial Paper		$ 3,000,000,000.0		$ 3,000,000,000.0					$ 3,000,000,000.0										$ 1,800,000,000
Mexico, Pesos | Financial Services Operations
Debt Instrument [Line Items]
Debt instrument, percentage of borrowings denominated in countries currency	80.00%	89.00%		89.00%				80.00%	89.00%
United States of America, Dollars
Debt Instrument [Line Items]
Commercial Paper	$ 140,000,000							$ 140,000,000									$ 84,000,000
United States of America, Dollars | Financial Services Operations
Debt Instrument [Line Items]
Debt instrument, percentage of borrowings denominated in countries currency	20.00%	11.00%		11.00%				20.00%	11.00%
International Truck Leasing Corporation [Member] | Financial Services Operations
Debt Instrument [Line Items]
Proceeds from issuance of securitized debt								$ 61,000,000	$ 31,000,000
Secured Debt	$ 117,000,000	$ 91,000,000		$ 91,000,000				117,000,000	91,000,000
Loans Pledged as Collateral	$ 144,000,000	109,000,000		109,000,000				$ 144,000,000	109,000,000
Navistar Financial Corporation [Member]
Debt Instrument [Line Items]
Debt Instrument, Covenant Compliance, Fixed Charge Coverage Ratio, Maximum	125.00%							125.00%
Navistar Financial Corporation [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 53,000,000	31,000,000		31,000,000				$ 53,000,000	31,000,000
Debt Instrument, Collateral Amount	$ 51,000,000	$ 30,000,000		$ 30,000,000				51,000,000	30,000,000
Debt Instrument, Increase (Decrease), Net								$ 28,000,000	$ 31,000,000
Interest Rate Floor [Member] | Financed lease obligations [Member] | Manufacturing Operations [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage																				3.77%
Interest Rate Cap [Member] | Financed lease obligations [Member] | Manufacturing Operations [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage																				5.91%
Affiliated Entity [Member] | NFM [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Long-term Debt										$ 13,000,000