Segment Information - Financial Information Related to Company's Reportable Segments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Segment Reporting Information [Line Items]
Total net sales	$ 7,133	$ 6,614	$ 19,887	$ 18,574
Total segment EBITA	1,170	998	2,913	2,521
Corporate expenses	(122)	(96)	(362)	(226)
Amortization of intangible assets	(111)	(102)	(319)	(326)
Restructuring and impairment costs	(81)	(121)	(844)	(554)
Net mark-to-market adjustments	17	(126)	16	(158)
Net financing charges	(80)	(49)	(218)	(153)
Income before income taxes	793	504	1,186	1,104
Building Solutions North America
Segment Reporting Information [Line Items]
Total net sales	2,665	2,426	7,552	6,805
Total segment EBITA	385	260	967	745
Building Solutions EMEA/LA
Segment Reporting Information [Line Items]
Total net sales	1,045	952	3,051	2,869
Total segment EBITA	90	83	234	266
Building Solutions Asia Pacific
Segment Reporting Information [Line Items]
Total net sales	736	665	2,049	1,963
Total segment EBITA	102	85	249	227
Global Products
Segment Reporting Information [Line Items]
Total net sales	2,687	2,571	7,235	6,937
Total segment EBITA	$ 593	$ 570	$ 1,463	$ 1,283