Goodwill And Other Intangible Assets (Schedule of Goodwill Balances) (Detail) (USD $) In Millions, unless otherwise specified			9 Months Ended
	Jun. 30, 2012	Sep. 30, 2011	Jun. 30, 2012 Rubber Blacks	Jun. 30, 2012 Fumed Metal Oxides Business	Jun. 30, 2012 Security Materials	Sep. 30, 2011 Security Materials
Goodwill [Line Items]
Balance at September 30, 2011	$ 40	$ 40	$ 27	$ 11	$ 2	$ 2
Foreign currency translation adjustment			1	(1)
Balance at June 30, 2012	$ 40	$ 40	$ 28	$ 10	$ 2	$ 2