Acquisitions and Divestitures (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Sep. 30, 2022
Business Acquisition [Line Items]
Cash paid for business acquisition	$ 79	$ 108
Goodwill	17,684		$ 17,328
Business divestitures, net of cash divested	0	16
Global Products
Business Acquisition [Line Items]
Goodwill	5,661		5,516
Building Solutions EMEA/LA
Business Acquisition [Line Items]
Goodwill	1,866		1,725
Building Solutions EMEA/LA | Business Divestitures, Not Specific
Business Acquisition [Line Items]
Proceeds from divestiture of businesses		18
Business divestitures, net of cash divested		16
Goodwill, written off related to sale of business unit		5
Building Solutions Asia Pacific
Business Acquisition [Line Items]
Goodwill	1,178		1,116
Building Solutions North America
Business Acquisition [Line Items]
Goodwill	8,979		$ 8,971
Individually Immaterial Acquisitions
Business Acquisition [Line Items]
Purchase price, net of cash acquired	105	142
Cash paid for business acquisition	79	108
Individually Immaterial Acquisitions | Global Products
Business Acquisition [Line Items]
Goodwill	53	10
Individually Immaterial Acquisitions | Building Solutions EMEA/LA
Business Acquisition [Line Items]
Goodwill	$ 2	19
Individually Immaterial Acquisitions | Building Solutions Asia Pacific
Business Acquisition [Line Items]
Goodwill		45
Individually Immaterial Acquisitions | Building Solutions North America
Business Acquisition [Line Items]
Goodwill		$ 20