Segment Reporting (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Segment Reporting Information [Line Items]
Net sales	$ 5,960	$ 5,919	$ 11,513	$ 11,228
Earnings before income taxes	831	814	1,504	1,367
Differences in accounting methods	54	55	104	104
Corporate and other	(139)	(119)	(262)	(248)
Interest expense	(57)	(58)	(111)	(116)
Number of active performance share plans			2
Process Management [Member]
Segment Reporting Information [Line Items]
Net sales	2,020	1,869	3,916	3,396
Earnings before income taxes	403	341	736	531
Industrial Automation [Member]
Segment Reporting Information [Line Items]
Net sales	1,213	1,284	2,350	2,513
Earnings before income taxes	186	203	350	385
Intersegment sales	177	163	298	273
Network Power [Member]
Segment Reporting Information [Line Items]
Net sales	1,481	1,549	2,940	3,044
Earnings before income taxes	111	134	216	256
Climate Technologies [Member]
Segment Reporting Information [Line Items]
Net sales	988	926	1,740	1,659
Earnings before income taxes	175	158	276	258
Commercial & Residential Solutions [Member]
Segment Reporting Information [Line Items]
Net sales	457	475	910	932
Earnings before income taxes	98	100	195	197
Segment Total [Member]
Segment Reporting Information [Line Items]
Net sales	6,159	6,103	11,856	11,544
Earnings before income taxes	973	936	1,773	1,627
Intersegment Elimination [Member]
Segment Reporting Information [Line Items]
Net sales	$ (199)	$ (184)	$ (343)	$ (316)