Discontinued Operations - Financial Results (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales	$ 3,205	$ 5,824	$ 5,304
Cost of sales	2,029	3,943	3,471
SG&A	397	633	685
Disposal group, loss on disposal	(13,393)	(486)	0
Other deductions, net	87	81	(2)
Earnings before income taxes	14,085	1,653	1,150
Income taxes	3,012	306	239
Earnings, net of tax	11,073	1,347	911
Climate Technologies
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales	3,156	4,976	4,401
Cost of sales	2,000	3,405	2,899
SG&A	390	514	560
Disposal group, loss on disposal	(10,610)	0	0
Other deductions, net	75	55	(10)
Earnings before income taxes	11,301	1,002	952
Income taxes	2,358	209	196
Earnings, net of tax	8,943	793	756
ISE and TOD
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales	49	848	903
Cost of sales	29	538	572
SG&A	7	119	125
Disposal group, loss on disposal	(2,783)	(486)	0
Other deductions, net	12	26	8
Earnings before income taxes	2,784	651	198
Income taxes	654	97	43
Earnings, net of tax	$ 2,130	$ 554	$ 155