Stock-Based Compensation (Stock-Based Compensation Expenses) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense before tax	$ 15	$ 15	$ 18
Income tax benefit	(5)	(5)	(7)
Net stock-based compensation expense	10	10	11
Cost Of Sales [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense before tax	5	5	6
Selling And Administrative Expenses [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense before tax	9	9	11
Research And Technical Expenses [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense before tax	$ 1	$ 1	$ 1