Equity Method Investment and Note Receivable (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended		6 Months Ended	9 Months Ended
	May 31, 2023	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2023	Jun. 30, 2022
Schedule of Equity Method Investments [Line Items]
Loss from equity method investment		$ 61	$ 0		$ 61	$ 0
Income tax benefit		(158)	(123)		(390)	(399)
Interest income		58	11		96	18
Settlement of notes receivable					918	0
Settlement of notes payable					918	0
Interest income from related party		(10)	$ 0		(10)	$ 0
Copeland
Schedule of Equity Method Investments [Line Items]
Equity method investment	$ 1,359	1,296		$ 1,296	1,296
Notes receivable	2,052	2,063		$ 2,063	2,063
Loss from equity method investment		61			61
Income tax benefit		$ 10			$ 10
Loss from equity method investment (in usd per share)		$ (0.09)			$ 0.09
Settlement of notes receivable		$ 918
Settlement of notes payable		918
Interest income from related party		$ 10
Climate Technologies (excluding Therm-O-Disc)
Schedule of Equity Method Investments [Line Items]
Noncontrolling interest, ownership percentage by parent		40.00%		40.00%	40.00%
Climate Technologies (excluding Therm-O-Disc)
Schedule of Equity Method Investments [Line Items]
Proceeds from divestiture	9,700			$ 9,700
Notes receivable, consideration	$ 2,250