Restructuring (Restructuring Activities and Related Reserves) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Restructuring Cost and Reserve [Line Items]
Reserve balance	$ 11	$ 19
Charges	15	18	46
Costs charged against assets and other	10	(6)
Proceeds from sale	4	6
Cash paid	(14)	(26)
Foreign currency translation adjustment	(1)
Reserve balance	5	11	19
Severance And Employee Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Reserve balance	9	18
Charges	3	8
Costs charged against assets and other		1
Cash paid	(10)	(17)
Foreign currency translation adjustment		(1)
Reserve balance	2	9
Environmental Remediation [Member]
Restructuring Cost and Reserve [Line Items]
Reserve balance		1
Charges	3	3
Cash paid	(2)	(4)
Reserve balance	1
Asset Impairment And Accelerated Depreciation [Member]
Restructuring Cost and Reserve [Line Items]
Charges	7	3
Costs charged against assets and other	7	(3)
Asset Sales [Member]
Restructuring Cost and Reserve [Line Items]
Charges	(1)	(1)
Costs charged against assets and other	3	(4)
Proceeds from sale	4	6
Cash paid		(1)
Other [Member]
Restructuring Cost and Reserve [Line Items]
Reserve balance	2
Charges	3	5
Cash paid	(2)	(4)
Foreign currency translation adjustment	(1)	1
Reserve balance	$ 2	$ 2