Restructuring Costs (Details) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Sep. 30, 2021 USD ($)
Restructuring Reserve [Roll Forward]
Beginning restructuring liability			$ 181
Restructuring expense	$ 28	$ 88	111	$ 216
Restructuring utilized/paid			117
Ending restructuring liability	175		$ 175
Total number of employee workforce reductions			1,900
Cost of sales and selling, general, and administrative expenses [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	4	6	$ 11	15
Severance and benefits [Member]
Restructuring Reserve [Roll Forward]
Beginning restructuring liability			176
Restructuring expense			87
Restructuring utilized/paid			95
Ending restructuring liability	168		168
Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Beginning restructuring liability			5
Restructuring expense			24
Restructuring utilized/paid			22
Ending restructuring liability	7		7
Automation Solutions [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	18	76	94	182
Commercial & Residential Solutions [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	6	9	12	26
Climate Technologies [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	4	5	8	14
Tools & Home Products [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	2	4	4	12
Corporate [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	$ 4	$ 3	$ 5	$ 8
Forecast [Member]
Restructuring Reserve [Roll Forward]
Expected fiscal year restructuring expense					$ 200