Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Millions	1 Months Ended	2 Months Ended	3 Months Ended		9 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Disaggregation of Revenue [Line Items]
Finance revenues			$ 46	$ 40	$ 141	$ 118
Sales and revenues, net			3,042	2,606	8,471	6,933
Truck products and services [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			2,118		5,900
Truck contract manufacturing [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			144		274
Used Trucks [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			54		151
Engines [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			136		385
Parts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			517		1,535
Extended warranty contracts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			27	24	85	80
Manufactured products, net [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			2,996		8,330
Retail [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			35		106
Interest income			15	42
Wholesale financing [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			11		35
Interest income			11			35
Military Sales [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net		$ 62
North America Truck [Member]
Disaggregation of Revenue [Line Items]
Sales and revenues, net			2,342		6,405
North America Truck [Member] | Truck products and services [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			2,115		5,891
North America Truck [Member] | Truck contract manufacturing [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			144		274
North America Truck [Member] | Used Trucks [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			54		151
North America Truck [Member] | Engines [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0		0
North America Truck [Member] | Parts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			2		4
North America Truck [Member] | Extended warranty contracts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			27		85
North America Truck [Member] | Manufactured products, net [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			2,342		6,405
North America Truck [Member] | Retail [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			0		0
North America Truck [Member] | Wholesale financing [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			0		0
North America Parts [Member]
Disaggregation of Revenue [Line Items]
Sales and revenues, net			569		1,693
North America Parts [Member] | Truck products and services [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0		0
North America Parts [Member] | Truck contract manufacturing [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0		0
North America Parts [Member] | Used Trucks [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0		0
North America Parts [Member] | Engines [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			73		217
North America Parts [Member] | Parts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			496		1,476
North America Parts [Member] | Extended warranty contracts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0		0
North America Parts [Member] | Manufactured products, net [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			569		1,693
North America Parts [Member] | Retail [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			0		0
North America Parts [Member] | Wholesale financing [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			0		0
Global Operations [Member]
Disaggregation of Revenue [Line Items]
Sales and revenues, net			82		223
Global Operations [Member] | Truck products and services [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0		0
Global Operations [Member] | Truck contract manufacturing [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0		0
Global Operations [Member] | Used Trucks [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0		0
Global Operations [Member] | Engines [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			63		168
Global Operations [Member] | Parts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			19		55
Global Operations [Member] | Extended warranty contracts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0		0
Global Operations [Member] | Manufactured products, net [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			82		223
Global Operations [Member] | Retail [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			0		0
Global Operations [Member] | Wholesale financing [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			0		0
Financial Services Operations
Disaggregation of Revenue [Line Items]
Finance revenues			46	$ 40	141	$ 118
Sales and revenues, net			46		141
Financial Services Operations | Truck products and services [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0		0
Financial Services Operations | Truck contract manufacturing [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0		0
Financial Services Operations | Used Trucks [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0		0
Financial Services Operations | Engines [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0		0
Financial Services Operations | Parts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0		0
Financial Services Operations | Extended warranty contracts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0		0
Financial Services Operations | Manufactured products, net [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0		0
Financial Services Operations | Retail [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			35		106
Financial Services Operations | Wholesale financing [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			11		35
Corporate And Eliminations [Member]
Disaggregation of Revenue [Line Items]
Sales and revenues, net			3		9
Corporate And Eliminations [Member] | Truck products and services [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			3		9
Corporate And Eliminations [Member] | Truck contract manufacturing [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0		0
Corporate And Eliminations [Member] | Used Trucks [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0		0
Corporate And Eliminations [Member] | Engines [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0		0
Corporate And Eliminations [Member] | Parts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0		0
Corporate And Eliminations [Member] | Extended warranty contracts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0		0
Corporate And Eliminations [Member] | Manufactured products, net [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			3		9
Corporate And Eliminations [Member] | Retail [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			0		0
Corporate And Eliminations [Member] | Wholesale financing [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			$ 0		$ 0
Navistar Defense [Member]
Disaggregation of Revenue [Line Items]
Equity Interest, Percent Sold	70.00%