Goodwill and Other Intangible Assets - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	1 Months Ended				12 Months Ended
	May 31, 2013	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2013 Cost of Sales and Selling and Administrative Expenses [Member]	Sep. 30, 2012 Cost of Sales and Selling and Administrative Expenses [Member]	Sep. 30, 2013 Maximum [Member]	Sep. 30, 2011 Maximum [Member] Cost of Sales [Member]	Sep. 30, 2013 Minimum [Member]	Sep. 30, 2013 Weighted Average [Member]
Goodwill And Intangible Assets [Line Items]
Goodwill		$ 504	$ 480	$ 40
Goodwill annual impairment	0
Useful life of intangible assets							20 years		6 years	19 years
Amortization of intangible assets					14	3		1
Amortization expense estimated for year one		14
Amortization expense estimated for year two		14
Amortization expense estimated for year three		14
Amortization expense estimated for year four		14
Amortization expense estimated for year five		14
Asset impairment charges	$ 0