Business Segments Information - Results of Operations by Business Segments (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Segment Reporting Information [Line Items]
Sales	$ 4,090	$ 3,946	$ 3,756	$ 3,373	$ 3,892	$ 3,465	$ 3,291	$ 3,156	$ 15,165	$ 13,804	$ 12,932
Earnings (Loss)									2,726	2,432	1,762
Total Assets	42,746				35,672				42,746	35,672	24,715
Total stock compensation expense									271	144	224
Gain on subordinated interest								$ (453)	(161)	(453)	0
Eliminations/Interest									(34)	(194)	(155)
Segment Reconciling Items
Segment Reporting Information [Line Items]
Total stock compensation expense									(250)	(125)	(197)
Unallocated pension and postretirement costs									171	99	94
Gain on subordinated interest									161	453	0
Loss on Copeland equity method investment									177	0	0
Segment Reconciling Items | Related Party
Segment Reporting Information [Line Items]
Interest income from related party									41	0	0
Corporate and other
Segment Reporting Information [Line Items]
Earnings (Loss)									(224)	(419)	(184)
Total Assets	13,226				6,879				13,226	6,879	7,729
Eliminations/Interest
Segment Reporting Information [Line Items]
Sales									(71)	(86)	(88)
Eliminations/Interest									(34)	(194)	(155)
Intelligent Devices
Segment Reporting Information [Line Items]
Sales									11,588	10,836	10,380
Earnings (Loss)									2,616	2,169	1,829
Total Assets	13,321				12,609				13,321	12,609	13,223
Intelligent Devices | Operating Segments | Final Control
Segment Reporting Information [Line Items]
Sales									3,970	3,607	3,488
Earnings (Loss)									865	592	432
Total Assets	5,614				4,805				5,614	4,805	5,245
Intelligent Devices | Operating Segments | Measurement & Analytical
Segment Reporting Information [Line Items]
Sales									3,595	3,215	3,078
Earnings (Loss)									936	785	684
Total Assets	3,976				4,395				3,976	4,395	4,410
Intelligent Devices | Operating Segments | Discrete Automation
Segment Reporting Information [Line Items]
Sales									2,635	2,612	2,474
Earnings (Loss)									509	542	457
Total Assets	2,493				2,284				2,493	2,284	2,405
Intelligent Devices | Operating Segments | Safety & Productivity
Segment Reporting Information [Line Items]
Sales									1,388	1,402	1,340
Earnings (Loss)									306	250	256
Total Assets	1,238				1,125				1,238	1,125	1,163
Software and Control
Segment Reporting Information [Line Items]
Sales									3,648	3,054	2,640
Earnings (Loss)									422	449	375
Total Assets	16,199				16,184				16,199	16,184	3,763
Software and Control | Operating Segments | Control Systems & Software
Segment Reporting Information [Line Items]
Sales									2,606	2,398	2,321
Earnings (Loss)									529	437	382
Total Assets	2,151				1,700				2,151	1,700	1,674
Software and Control | Operating Segments | AspenTech
Segment Reporting Information [Line Items]
Sales									1,042	656	319
Earnings (Loss)									(107)	12	(7)
Total Assets	$ 14,048				$ 14,484				$ 14,048	$ 14,484	$ 2,089