RESTRUCTURING COSTS - Additional Information (Details) $ in Millions	3 Months Ended						6 Months Ended		12 Months Ended			22 Months Ended
	Sep. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Mar. 31, 2016 USD ($)	Mar. 31, 2015 USD ($) position	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($) position	Sep. 30, 2015 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 2	$ 4	$ 7	$ 6	$ 2	$ 1			$ 6	$ 16	$ 16
Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring costs	2								0	2	2
Employee separation
Restructuring Cost and Reserve [Line Items]
Restructuring costs									5	15	15
Commercial Truck & Industrial
Restructuring Cost and Reserve [Line Items]
Restructuring costs									2	6	14
Aftermarket & Trailer
Restructuring Cost and Reserve [Line Items]
Restructuring costs									4	8	0
Commercial Truck and Industrial, Aftermarket and Trailer
Restructuring Cost and Reserve [Line Items]
Restructuring costs				$ 5					4
Aftermarket actions
Restructuring Cost and Reserve [Line Items]
Restructuring costs										8
Aftermarket actions | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring costs										2
Aftermarket actions | Commercial Truck & Industrial
Restructuring Cost and Reserve [Line Items]
Restructuring costs	5									5
Aftermarket actions | Aftermarket & Trailer
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 1									1
Other
Restructuring Cost and Reserve [Line Items]
Restructuring costs									2	3	1
Other | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring costs									0	0	0
Other | Commercial Truck & Industrial
Restructuring Cost and Reserve [Line Items]
Restructuring costs									2	1	1
Other | Aftermarket & Trailer
Restructuring Cost and Reserve [Line Items]
Restructuring costs									$ 0	$ 2	0
Other | Commercial Truck and Industrial, Aftermarket and Trailer
Restructuring Cost and Reserve [Line Items]
Restructuring costs							$ 3
M2016 footprint actions
Restructuring Cost and Reserve [Line Items]
Restructuring costs											5
M2016 footprint actions | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring costs											0
M2016 footprint actions | Commercial Truck & Industrial
Restructuring Cost and Reserve [Line Items]
Restructuring costs											5	$ 7
M2016 footprint actions | Aftermarket & Trailer
Restructuring Cost and Reserve [Line Items]
Restructuring costs											$ 0
M2016 footprint actions | Hourly and Salaried Positions | Commercial Truck & Industrial
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | position											140
South America labor reduction I | Commercial Truck & Industrial
Restructuring Cost and Reserve [Line Items]
Restructuring costs											$ 13
South America labor reduction I | Hourly Positions | Commercial Truck & Industrial
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | position											420
South America labor reduction I | Salaried Positions | Commercial Truck & Industrial
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | position											40
Closure of engineering facility
Restructuring Cost and Reserve [Line Items]
Restructuring costs											$ 2
Closure of engineering facility | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring costs											2
Closure of engineering facility | Employee separation
Restructuring Cost and Reserve [Line Items]
Cost incurred to date								$ 2
Closure of engineering facility | Commercial Truck & Industrial
Restructuring Cost and Reserve [Line Items]
Restructuring costs											0
Closure of engineering facility | Aftermarket & Trailer
Restructuring Cost and Reserve [Line Items]
Restructuring costs											0
Closure of engineering facility | Hourly and Salaried Positions
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | position								30
European labor reductions
Restructuring Cost and Reserve [Line Items]
Restructuring costs											2
European labor reductions | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring costs											0
European labor reductions | Commercial Truck & Industrial
Restructuring Cost and Reserve [Line Items]
Restructuring costs											2
Cost incurred to date								$ 2
European labor reductions | Aftermarket & Trailer
Restructuring Cost and Reserve [Line Items]
Restructuring costs											$ 0
European labor reductions | Hourly Positions | Commercial Truck & Industrial
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | position								20
European labor reductions | Salaried Positions | Commercial Truck & Industrial
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | position								20