Restructuring, Impairments and Divestitures - Narrative (Details) - USD ($)	1 Months Ended	3 Months Ended
	Dec. 31, 2018	Jan. 31, 2020	Jan. 31, 2019	Oct. 31, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ (1,000,000)	$ 0
Liability, Defined Benefit Plan, Noncurrent		2,056,000,000		$ 2,103,000,000
Asset impairment charges		0	2,000,000
Goodwill		38,000,000		$ 38,000,000
Gain (Loss) on Sales of Investments and Businesses, Net		$ 0	59,000,000
Navistar Defense [Member]
Restructuring Cost and Reserve [Line Items]
Proceeds from Divestiture of Businesses	$ 140,000,000
Equity Interest, Percent Sold	70.00%
Gain (Loss) on Sales of Investments and Businesses, Net	$ 54,000,000
Assets Leased to Others [Member]
Restructuring Cost and Reserve [Line Items]
Asset impairment charges			$ 2,000,000