INVESTMENTS IN NON-CONSOLIDATED JOINT VENTURES - Investments In Non-Consolidated Joint Ventures (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Investments in non-consolidated joint ventures	$ 101	$ 100
Commercial Truck & Industrial
Segment Reporting Information [Line Items]
Investments in non-consolidated joint ventures	101	100
Aftermarket & Trailer
Segment Reporting Information [Line Items]
Investments in non-consolidated joint ventures	$ 0	$ 0

Total investments in (A) an entity in which the entity has significant influence, but does not have control, (B) subsidiaries that are not required to be consolidated and are accounted for using the equity and or cost method, and (C) an entity in which the reporting entity shares control of the entity with another party or group. Includes long-term advances receivable from a party that is affiliated with the reporting entity by means of direct or indirect ownership.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant