Segment Reporting (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2012	Mar. 31, 2011
Segment Reporting Information [Line Items]
Segment Sales	$ 6,103	$ 6,046	$ 11,544	$ 11,723
Segment Earnings	936	934	1,627	1,807
Net sales	5,919	5,854	11,228	11,389
Earnings before income taxes	814	833	1,367	1,546
Change in stock compensation expense			(31)
Interest expense	(58)	(57)	(116)	(118)
Acquisition-related costs				15
Joint Venture Ownership Acquisition Gain		15
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
Process Management [Member]
Segment Reporting Information [Line Items]
Segment Sales	1,869	1,653	3,396	3,195
Segment Earnings	341	296	531	586
Industrial Automation [Member]
Segment Reporting Information [Line Items]
Segment Sales	1,284	1,308	2,513	2,518
Segment Earnings	203	210	385	395
Intersegment sales	163	176	273	302
Network Power [Member]
Segment Reporting Information [Line Items]
Segment Sales	1,549	1,616	3,044	3,285
Segment Earnings	134	150	256	332
Climate Technologies [Member]
Segment Reporting Information [Line Items]
Segment Sales	926	1,014	1,659	1,824
Segment Earnings	158	187	258	310
Commercial & Residential Solutions [Member]
Segment Reporting Information [Line Items]
Segment Sales	475	455	932	901
Segment Earnings	100	91	197	184
Differences In Accounting Methods [Member]
Segment Reporting Information [Line Items]
Differences in accounting methods	55	56	104	109
Corporate And Other [Member]
Segment Reporting Information [Line Items]
Segment Earnings	(119)	(100)	(248)	(252)
Eliminations/Interest [Member]
Segment Reporting Information [Line Items]
Segment Sales	(184)	(192)	(316)	(334)
Interest expense	$ (58)	$ (57)	$ (116)	$ (118)