Restructuring Costs (Details) $ in Millions	3 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2021 USD ($)
Restructuring Reserve [Roll Forward]
Beginning restructuring liability	$ 181
Restructuring expense	66	$ 97
Restructuring utilized/paid	34
Ending restructuring liability	$ 213
Total number of employee workforce reductions	800
Cost of sales and selling, general, and administrative expenses [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	$ 3
Severance and benefits [Member]
Restructuring Reserve [Roll Forward]
Beginning restructuring liability	176
Restructuring expense	61
Restructuring utilized/paid	28
Ending restructuring liability	209
Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Beginning restructuring liability	5
Restructuring expense	5
Restructuring utilized/paid	6
Ending restructuring liability	4
Automation Solutions [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	64	83
Commercial & Residential Solutions [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	2	10
Climate Technologies [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	1	7
Tools & Home Products [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	1	3
Corporate [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	$ 0	$ 4
Forecast [Member]
Restructuring Reserve [Roll Forward]
Expected fiscal year restructuring expense			$ 200