Segment Reporting (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 employees	Jun. 30, 2011
Segment Reporting Information [Line Items]
Segment Sales	$ 6,715	$ 6,506	$ 18,259	$ 18,229
Segment Earnings	1,242	1,097	2,869	2,904
Net sales	6,484	6,288	17,712	17,677
Earnings before income taxes	1,155	992	2,522	2,538
Change in stock compensation expense	(23)		(55)
Interest expense	(51)	(56)	(167)	(174)
Charge for the elimination of post-65 supplemental retiree medical benefits			17
Approximate number of active employees affected by elimination of post-65 supplemental retiree medical benefits			8,000
Joint Venture Ownership Acquisition Gain				15
Purchase Accounting Adjustments				15
Process Management [Member]
Segment Reporting Information [Line Items]
Segment Sales	2,122	1,789	5,518	4,984
Segment Earnings	490	366	1,021	952
Industrial Automation [Member]
Segment Reporting Information [Line Items]
Segment Sales	1,378	1,391	3,891	3,909
Segment Earnings	259	230	644	625
Intersegment sales	206	198	479	500
Network Power [Member]
Segment Reporting Information [Line Items]
Segment Sales	1,588	1,683	4,632	4,968
Segment Earnings	163	176	419	508
Climate Technologies [Member]
Segment Reporting Information [Line Items]
Segment Sales	1,146	1,171	2,805	2,995
Segment Earnings	232	229	490	539
Commercial & Residential Solutions [Member]
Segment Reporting Information [Line Items]
Segment Sales	481	472	1,413	1,373
Segment Earnings	98	96	295	280
Differences In Accounting Methods [Member]
Segment Reporting Information [Line Items]
Differences in accounting methods	59	60	163	169
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Segment Earnings	(95)	(109)	(343)	(361)
Eliminations Interest [Member]
Segment Reporting Information [Line Items]
Segment Sales	(231)	(218)	(547)	(552)
Interest expense	$ (51)	$ (56)	$ (167)	$ (174)