Business Segment Information (Details 2) - USD ($) $ in Millions	Jun. 30, 2015	Sep. 30, 2014
Segment Reporting Information [Line Items]
Total assets	$ 2,453	$ 2,502
Less: Accounts receivable sold under off-balance sheet factoring programs	(315)	(244)
Operating Segments
Segment Reporting Information [Line Items]
Total assets	2,155	2,213
Operating Segments | Commercial Truck & Industrial
Segment Reporting Information [Line Items]
Total assets	1,710	1,755
Operating Segments | Aftermarket & Trailer
Segment Reporting Information [Line Items]
Total assets	445	458
Corporate
Segment Reporting Information [Line Items]
Total assets	613	533
Segment Reconciling Items
Segment Reporting Information [Line Items]
Less: Accounts receivable sold under off-balance sheet factoring programs	$ (315)	$ (244)