Business Segment Information (Details 2) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Sep. 30, 2011
Total assets	$ 2,565	$ 2,663
Less: Accounts receivable sold under off-balance sheet factoring programs	(287)	(280)
Commercial Truck Segment [Member]
Total assets	1,512	1,482
Industrial Segment [Member]
Total assets	480	470
Aftermarket and Trailer Segment [Member]
Total assets	526	504
Segment Assets [Member]
Total assets	2,518	2,456
Corporate [Member]
Total assets	334	483
Segment, Discontinued Operations [Member]
Total assets	$ 0	$ 4