Restructuring (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Restructuring Reserve [Roll Forward]
Beginning restructuring liability	$ 52
Restructuring expense	10	$ 15
Restructuring utilized/paid	17
Ending restructuring liability	45
Severance and benefits [Member]
Restructuring Reserve [Roll Forward]
Beginning restructuring liability	46
Restructuring expense	5
Restructuring utilized/paid	11
Ending restructuring liability	40
Lease and other contract terminations [Member]
Restructuring Reserve [Roll Forward]
Beginning restructuring liability	3
Restructuring expense	0
Restructuring utilized/paid	1
Ending restructuring liability	2
Assets Write Downs [Member]
Restructuring Reserve [Roll Forward]
Beginning restructuring liability	0
Restructuring expense	1
Restructuring utilized/paid	1
Ending restructuring liability	0
Vacant facility and other shutdown costs [Member]
Restructuring Reserve [Roll Forward]
Beginning restructuring liability	3
Restructuring expense	2
Restructuring utilized/paid	2
Ending restructuring liability	3
Start-up and moving costs [Member]
Restructuring Reserve [Roll Forward]
Beginning restructuring liability	0
Restructuring expense	2
Restructuring utilized/paid	2
Ending restructuring liability	0
Automation Solutions [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	5	10
Commercial & Residential Solutions [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	5	5
Climate Technologies [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	3	5
Tools & Home Products [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	$ 2	$ 0