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, 2020	Jul. 31, 2019	Jul. 31, 2020	Jul. 31, 2019
Disaggregation of Revenue [Line Items]
Finance revenues			$ 36	$ 46	$ 128	$ 141
Sales and revenues, net			1,675	3,042	5,438	8,471
Truck products and services [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			1,043	2,118	3,381	5,900
Truck contract manufacturing [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			71	144	227	274
Used Trucks [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			42	54	125	151
Engines [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			83	136	265	385
Parts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			377	517	1,238	1,535
Extended warranty contracts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			23	27	74	85
Manufactured products, net [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			1,639	2,996	5,310	8,330
Retail [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			30	35	104	106
Wholesale financing [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			6	11	24	35
Interest income			6	11	24	35
Military Sales [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net		$ 62
Finance Revenue, Net [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			36	46	128	141
North America Truck [Member]
Disaggregation of Revenue [Line Items]
Sales and revenues, net			1,177	2,342	3,800	6,405
North America Truck [Member] | Truck products and services [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			1,040	2,115	3,372	5,891
North America Truck [Member] | Truck contract manufacturing [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			71	144	227	274
North America Truck [Member] | Used Trucks [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			42	54	125	151
North America Truck [Member] | Engines [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0	0	0	0
North America Truck [Member] | Parts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			1	2	2	4
North America Truck [Member] | Extended warranty contracts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			23	27	74	85
North America Truck [Member] | Manufactured products, net [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			1,177	2,342	3,800	6,405
North America Truck [Member] | Retail [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			0	0	0	0
North America Truck [Member] | Wholesale financing [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			0	0	0	0
North America Truck [Member] | Finance Revenue, Net [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			0	0	0	0
North America Parts [Member]
Disaggregation of Revenue [Line Items]
Sales and revenues, net			413	569	1,347	1,693
North America Parts [Member] | Truck products and services [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0	0	0	0
North America Parts [Member] | Truck contract manufacturing [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0	0	0	0
North America Parts [Member] | Used Trucks [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0	0	0	0
North America Parts [Member] | Engines [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			48	73	147	217
North America Parts [Member] | Parts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			365	496	1,200	1,476
North America Parts [Member] | Extended warranty contracts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0	0	0	0
North America Parts [Member] | Manufactured products, net [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			413	569	1,347	1,693
North America Parts [Member] | Retail [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			0	0	0	0
North America Parts [Member] | Wholesale financing [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			0	0	0	0
North America Parts [Member] | Finance Revenue, Net [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			0	0	0	0
Global Operations [Member]
Disaggregation of Revenue [Line Items]
Sales and revenues, net			46	82	154	223
Global Operations [Member] | Truck products and services [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0	0	0	0
Global Operations [Member] | Truck contract manufacturing [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0	0	0	0
Global Operations [Member] | Used Trucks [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0	0	0	0
Global Operations [Member] | Engines [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			35	63	118	168
Global Operations [Member] | Parts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			11	19	36	55
Global Operations [Member] | Extended warranty contracts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0	0	0	0
Global Operations [Member] | Manufactured products, net [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			46	82	154	223
Global Operations [Member] | Retail [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			0	0	0	0
Global Operations [Member] | Wholesale financing [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			0	0	0	0
Global Operations [Member] | Finance Revenue, Net [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			0	0	0	0
Financial Services Operations
Disaggregation of Revenue [Line Items]
Finance revenues			39	46	135	141
Sales and revenues, net			39	46	135	141
Interest Revenue (Expense), Net			29	53	103	161
Financial Services Operations | Truck products and services [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0	0	0	0
Financial Services Operations | Truck contract manufacturing [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0	0	0	0
Financial Services Operations | Used Trucks [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0	0	0	0
Financial Services Operations | Engines [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0	0	0	0
Financial Services Operations | Parts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0	0	0	0
Financial Services Operations | Extended warranty contracts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0	0	0	0
Financial Services Operations | Manufactured products, net [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0	0	0	0
Financial Services Operations | Retail [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			33	35	111	106
Interest Revenue (Expense), Net			13	15	44	42
Financial Services Operations | Wholesale financing [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			6	11	24	35
Financial Services Operations | Finance Revenue, Net [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			39	46	135	141
Corporate And Eliminations [Member]
Disaggregation of Revenue [Line Items]
Sales and revenues, net			0	3	2	9
Corporate And Eliminations [Member] | Truck products and services [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			3	3	9	9
Corporate And Eliminations [Member] | Truck contract manufacturing [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0	0	0	0
Corporate And Eliminations [Member] | Used Trucks [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0	0	0	0
Corporate And Eliminations [Member] | Engines [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0	0	0	0
Corporate And Eliminations [Member] | Parts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0	0	0	0
Corporate And Eliminations [Member] | Extended warranty contracts [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			0	0	0	0
Corporate And Eliminations [Member] | Manufactured products, net [Member]
Disaggregation of Revenue [Line Items]
Sales of manufactured products, net			3	3	9	9
Corporate And Eliminations [Member] | Retail [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			(3)	0	(7)	0
Corporate And Eliminations [Member] | Wholesale financing [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			0	0	0	0
Corporate And Eliminations [Member] | Finance Revenue, Net [Member]
Disaggregation of Revenue [Line Items]
Finance revenues			$ (3)	$ 0	$ (7)	$ 0
Navistar Defense [Member]
Disaggregation of Revenue [Line Items]
Equity Interest, Percent Sold	70.00%