Significant Restructuring and Impairment Costs (Changes in Company's Restructuring Reserve) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended					12 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Sep. 30, 2012	Jun. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning balance						$ 228	$ 297
Restructuring and impairment costs	758	143	84	245	52	985	297	0
Utilized - cash						(148)	(22)
Utilized - noncash						(588)	(47)
Restructuring held for sale						(31)
Restructuring reserve, ending balance	446			228		446	228	297
Employee Severance and Termination Benefits
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning balance						221	237
Restructuring and impairment costs						392
Utilized - cash						(141)	(16)
Utilized - noncash						0	0
Restructuring held for sale						(31)
Restructuring reserve, ending balance	441			221		441	221
Fixed Asset Impairment
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning balance						0	39
Restructuring and impairment costs						156
Utilized - cash						0	0
Utilized - noncash						(156)	(39)
Restructuring held for sale						0
Restructuring reserve, ending balance	0			0		0	0
Goodwill Impairment
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning balance						0	0
Restructuring and impairment costs						430
Utilized - cash						0	0
Utilized - noncash						(430)	0
Restructuring held for sale						0
Restructuring reserve, ending balance	0			0		0	0
Other
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning balance						7	21
Restructuring and impairment costs						7
Utilized - cash						(7)	(6)
Utilized - noncash						(4)	(8)
Restructuring held for sale						0
Restructuring reserve, ending balance	3			7		3	7
Currency Translation
Restructuring Cost and Reserve [Line Items]
Restructuring reserve, beginning balance						0	0
Restructuring and impairment costs						0
Utilized - cash						0	0
Utilized - noncash						2	0
Restructuring held for sale						0
Restructuring reserve, ending balance	$ 2			$ 0		$ 2	$ 0