Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Total	$ 6,068	$ 5,862
Products and systems
Disaggregation of Revenue [Line Items]
Total	4,556	4,420
Services
Disaggregation of Revenue [Line Items]
Total	1,512	1,442
Building Solutions North America
Disaggregation of Revenue [Line Items]
Total	2,367	2,152
Building Solutions North America | Products and systems
Disaggregation of Revenue [Line Items]
Total	1,451	1,299
Building Solutions North America | Services
Disaggregation of Revenue [Line Items]
Total	916	853
Building Solutions EMEA/LA
Disaggregation of Revenue [Line Items]
Total	975	959
Building Solutions EMEA/LA | Products and systems
Disaggregation of Revenue [Line Items]
Total	552	544
Building Solutions EMEA/LA | Services
Disaggregation of Revenue [Line Items]
Total	423	415
Building Solutions Asia Pacific
Disaggregation of Revenue [Line Items]
Total	646	675
Building Solutions Asia Pacific | Products and systems
Disaggregation of Revenue [Line Items]
Total	473	501
Building Solutions Asia Pacific | Services
Disaggregation of Revenue [Line Items]
Total	173	174
Global Products
Disaggregation of Revenue [Line Items]
Total	2,080	2,076
Global Products | Products and systems
Disaggregation of Revenue [Line Items]
Total	2,080	2,076
Global Products | HVAC
Disaggregation of Revenue [Line Items]
Total	1,440	1,483
Global Products | Fire & Security
Disaggregation of Revenue [Line Items]
Total	570	544
Global Products | Industrial Refrigeration
Disaggregation of Revenue [Line Items]
Total	70	49
Global Products | Services
Disaggregation of Revenue [Line Items]
Total	$ 0	$ 0