Business Segments Information (Financial Information By Geographic Area) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Net sales	$ 5,360	$ 5,005	$ 4,791	$ 4,473	$ 4,947	$ 4,697	$ 4,431	$ 4,161	$ 19,629	$ 18,236	$ 16,785
United States
Segment Reporting Information [Line Items]
Net sales									9,084	7,952	7,420
Property, Plant and Equipment	2,006				2,141				2,006	2,141	2,124
China
Segment Reporting Information [Line Items]
Net sales									2,331	2,252	1,845
Reportable Geographical Components [Member]
Segment Reporting Information [Line Items]
Net sales									19,647	18,264	16,800
Property, Plant and Equipment	3,361				3,738				3,361	3,738	3,688
Reportable Geographical Components [Member] | Americas [Member]
Segment Reporting Information [Line Items]
Net sales									11,016	9,614	8,940
Property, Plant and Equipment	2,255				2,375				2,255	2,375	2,345
Reportable Geographical Components [Member] | Asia, Middle East & Africa
Segment Reporting Information [Line Items]
Net sales									5,456	5,323	4,856
Property, Plant and Equipment	576				678				576	678	679
Reportable Geographical Components [Member] | Europe [Member]
Segment Reporting Information [Line Items]
Net sales									3,175	3,327	3,004
Property, Plant and Equipment	$ 530				$ 685				530	685	664
Automation Solutions [Member] | Reportable Geographical Components [Member]
Segment Reporting Information [Line Items]
Net sales									11,758	11,292	11,026
Automation Solutions [Member] | Reportable Geographical Components [Member] | Americas [Member]
Segment Reporting Information [Line Items]
Net sales									5,548	4,901	5,004
Automation Solutions [Member] | Reportable Geographical Components [Member] | Asia, Middle East & Africa
Segment Reporting Information [Line Items]
Net sales									4,049	3,986	3,761
Automation Solutions [Member] | Reportable Geographical Components [Member] | Europe [Member]
Segment Reporting Information [Line Items]
Net sales									2,161	2,405	2,261
Commercial & Residential Solutions [Member] | Reportable Geographical Components [Member]
Segment Reporting Information [Line Items]
Net sales									7,233	6,653	5,643
Commercial & Residential Solutions [Member] | Reportable Geographical Components [Member] | Americas [Member]
Segment Reporting Information [Line Items]
Net sales									5,106	4,513	3,896
Commercial & Residential Solutions [Member] | Reportable Geographical Components [Member] | Asia, Middle East & Africa
Segment Reporting Information [Line Items]
Net sales									1,267	1,277	1,053
Commercial & Residential Solutions [Member] | Reportable Geographical Components [Member] | Europe [Member]
Segment Reporting Information [Line Items]
Net sales									860	863	694
AspenTech [Member] | Reportable Geographical Components [Member]
Segment Reporting Information [Line Items]
Net sales									656	319	131
AspenTech [Member] | Reportable Geographical Components [Member] | Americas [Member]
Segment Reporting Information [Line Items]
Net sales									362	200	40
AspenTech [Member] | Reportable Geographical Components [Member] | Asia, Middle East & Africa
Segment Reporting Information [Line Items]
Net sales									140	60	42
AspenTech [Member] | Reportable Geographical Components [Member] | Europe [Member]
Segment Reporting Information [Line Items]
Net sales									$ 154	$ 59	$ 49