Significant Restructuring and Impairment Costs - Schedule of Restructuring Reserve by Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Restructuring Cost and Reserve [Line Items]
Restructuring costs and asset impairment charges	$ 418	$ 384	$ 763	$ 433
Various 2023 Restructuring Plans
Restructuring Cost and Reserve [Line Items]
Restructuring costs and asset impairment charges	24		81
Building Solutions North America | Various 2023 Restructuring Plans
Restructuring Cost and Reserve [Line Items]
Restructuring costs and asset impairment charges	4		6
Building Solutions EMEA/LA | Various 2023 Restructuring Plans
Restructuring Cost and Reserve [Line Items]
Restructuring costs and asset impairment charges	0		21
Building Solutions Asia Pacific | Various 2023 Restructuring Plans
Restructuring Cost and Reserve [Line Items]
Restructuring costs and asset impairment charges	1		6
Global Products | Various 2023 Restructuring Plans
Restructuring Cost and Reserve [Line Items]
Restructuring costs and asset impairment charges	4		27
Corporate | Various 2023 Restructuring Plans
Restructuring Cost and Reserve [Line Items]
Restructuring costs and asset impairment charges	$ 15		$ 21