Restructuring (Details) $ in Millions	3 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2020 USD ($)
Restructuring Reserve [Roll Forward]
Beginning restructuring liability	$ 69
Restructuring expense	97	$ 10
Restructuring utilized/paid	39
Ending restructuring liability	$ 127
Total number of employee workforce reductions	1,100
Severance and benefits [Member]
Restructuring Reserve [Roll Forward]
Beginning restructuring liability	$ 62
Restructuring expense	80
Restructuring utilized/paid	20
Ending restructuring liability	122
Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Beginning restructuring liability	7
Restructuring expense	17
Restructuring utilized/paid	19
Ending restructuring liability	5
Automation Solutions [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	83	5
Commercial & Residential Solutions [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	10	5
Climate Technologies [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	7	3
Tools & Home Products [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	3	2
Corporate [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	$ 4	$ 0
Forecast [Member]
Restructuring Reserve [Roll Forward]
Expected fiscal year restructuring expense			$ 215