Net Property (Details) - USD ($) $ in Millions	Jun. 30, 2015	Sep. 30, 2014
Property, Plant and Equipment [Line Items]
Property at cost	$ 1,298	$ 1,397
Less accumulated depreciation	(905)	(973)
Net property	393	424
Land and land improvements
Property, Plant and Equipment [Line Items]
Property at cost	32	34
Buildings
Property, Plant and Equipment [Line Items]
Property at cost	216	236
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property at cost	867	906
Company-owned tooling
Property, Plant and Equipment [Line Items]
Property at cost	127	155
Construction in progress
Property, Plant and Equipment [Line Items]
Property at cost	$ 56	$ 66