Business Segments Information (Financial Information By Geographic Area) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Net sales	$ 4,947	$ 4,697	$ 4,431	$ 4,161	$ 4,558	$ 3,914	$ 4,162	$ 4,151	$ 18,236	$ 16,785	$ 18,372
United States
Segment Reporting Information [Line Items]
Net sales									7,952	7,420	8,390
Property, Plant and Equipment	2,141				2,124				2,141	2,124	2,128
China
Segment Reporting Information [Line Items]
Net sales									2,252	1,845	1,962
Reportable Geographical Components [Member]
Segment Reporting Information [Line Items]
Net sales									18,263	16,798	18,371
Property, Plant and Equipment	3,738				3,688				3,738	3,688	3,642
Reportable Geographical Components [Member] | Americas [Member]
Segment Reporting Information [Line Items]
Net sales									9,613	8,947	10,103
Property, Plant and Equipment	2,375				2,345				2,375	2,345	2,339
Reportable Geographical Components [Member] | Asia, Middle East & Africa
Segment Reporting Information [Line Items]
Net sales									5,323	4,854	5,083
Property, Plant and Equipment	678				679				678	679	671
Reportable Geographical Components [Member] | Europe [Member]
Segment Reporting Information [Line Items]
Net sales									3,327	2,997	3,185
Property, Plant and Equipment	$ 685				$ 664				685	664	632
Automation Solutions [Member] | Reportable Geographical Components [Member]
Segment Reporting Information [Line Items]
Net sales									11,610	11,155	12,202
Automation Solutions [Member] | Reportable Geographical Components [Member] | Americas [Member]
Segment Reporting Information [Line Items]
Net sales									5,100	5,051	5,850
Automation Solutions [Member] | Reportable Geographical Components [Member] | Asia, Middle East & Africa
Segment Reporting Information [Line Items]
Net sales									4,046	3,801	3,891
Automation Solutions [Member] | Reportable Geographical Components [Member] | Europe [Member]
Segment Reporting Information [Line Items]
Net sales									2,464	2,303	2,461
Commercial & Residential Solutions [Member] | Reportable Geographical Components [Member]
Segment Reporting Information [Line Items]
Net sales									6,653	5,643	6,169
Commercial & Residential Solutions [Member] | Reportable Geographical Components [Member] | Americas [Member]
Segment Reporting Information [Line Items]
Net sales									4,513	3,896	4,253
Commercial & Residential Solutions [Member] | Reportable Geographical Components [Member] | Asia, Middle East & Africa
Segment Reporting Information [Line Items]
Net sales									1,277	1,053	1,192
Commercial & Residential Solutions [Member] | Reportable Geographical Components [Member] | Europe [Member]
Segment Reporting Information [Line Items]
Net sales									$ 863	$ 694	$ 724