Restructuring Costs (Details) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Sep. 30, 2020 USD ($)
Restructuring Reserve [Roll Forward]
Beginning restructuring liability			$ 69
Restructuring expense	$ 31	$ 10	128	$ 20
Restructuring utilized/paid			83
Ending restructuring liability	114		$ 114
Total number of employee workforce reductions			1,800
Cost of Sales [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	9		$ 9
Severance and benefits [Member]
Restructuring Reserve [Roll Forward]
Beginning restructuring liability			62
Restructuring expense			105
Restructuring utilized/paid			57
Ending restructuring liability	110		110
Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Beginning restructuring liability			7
Restructuring expense			23
Restructuring utilized/paid			26
Ending restructuring liability	4		4
Automation Solutions [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	23	6	106	11
Commercial & Residential Solutions [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	7	3	17	8
Climate Technologies [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	2	1	9	4
Tools & Home Products [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	5	2	8	4
Corporate [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	$ 1	$ 1	$ 5	$ 1
Forecast [Member]
Restructuring Reserve [Roll Forward]
Expected fiscal year restructuring expense					$ 280
Increase (decrease) in expected restructuring related costs					$ 65