Derivative Instruments and Hedging Activities - Cash Flow Hedges (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives, Net of Tax			$ (34)
Cash flow hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives, Net of Tax	2		(34)
Gain (Loss) Reclassified from Accumulated OCI into Income, Net of Tax	(4)	(5)	(1)
Cash flow hedges [Member] | Interest rate swaps [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives, Net of Tax		1	(34)
Cash flow hedges [Member] | Commodity forward contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives, Net of Tax	2	(1)
Cash flow hedges [Member] | Interest expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income, Net of Tax	(5)	(5)	(1)
Cash flow hedges [Member] | Cost of products sold [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income, Net of Tax	$ 1