Segment Information - Financial Information Related to Company's Reportable Segments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Segment Reporting Information [Line Items]
Total net sales	$ 6,686	$ 6,098	$ 12,754	$ 11,960
Total segment EBITA	951	800	1,743	1,523
Corporate expenses	(131)	(60)	(240)	(130)
Amortization of intangible assets	(104)	(106)	(208)	(224)
Restructuring and impairment costs	(418)	(384)	(763)	(433)
Net mark-to-market adjustments	(4)	(89)	(1)	(32)
Net financing charges	(71)	(51)	(138)	(104)
Income before income taxes	223	110	393	600
Building Solutions North America
Segment Reporting Information [Line Items]
Total net sales	2,520	2,227	4,887	4,379
Total segment EBITA	315	235	582	485
Building Solutions EMEA/LA
Segment Reporting Information [Line Items]
Total net sales	1,031	958	2,006	1,917
Total segment EBITA	69	79	144	183
Building Solutions Asia Pacific
Segment Reporting Information [Line Items]
Total net sales	667	623	1,313	1,298
Total segment EBITA	79	74	147	142
Global Products
Segment Reporting Information [Line Items]
Total net sales	2,468	2,290	4,548	4,366
Total segment EBITA	$ 488	$ 412	$ 870	$ 713