Restructuring (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Sep. 30, 2018
Restructuring Reserve [Roll Forward]
Beginning restructuring liability			$ 65
Restructuring expense	$ 14	$ 21	38	$ 45
Restructuring utilized/paid			60
Ending restructuring liability	43		43
Severance and benefits [Member]
Restructuring Reserve [Roll Forward]
Beginning restructuring liability			60
Restructuring expense			24
Restructuring utilized/paid			48
Ending restructuring liability	36		36
Lease and other contract terminations [Member]
Restructuring Reserve [Roll Forward]
Beginning restructuring liability			4
Restructuring expense			2
Restructuring utilized/paid			2
Ending restructuring liability	4		4
Assets Write Downs [Member]
Restructuring Reserve [Roll Forward]
Beginning restructuring liability			0
Restructuring expense			1
Restructuring utilized/paid			1
Ending restructuring liability	0		0
Vacant facility and other shutdown costs [Member]
Restructuring Reserve [Roll Forward]
Beginning restructuring liability			1
Restructuring expense			4
Restructuring utilized/paid			3
Ending restructuring liability	2		2
Start-up and moving costs [Member]
Restructuring Reserve [Roll Forward]
Beginning restructuring liability			0
Restructuring expense			7
Restructuring utilized/paid			6
Ending restructuring liability	1		1
Automation Solutions [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	9	20	26	35
Commercial & Residential Solutions [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	4	1	11	9
Climate Technologies [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	4	1	11	8
Tools & Home Products [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	0	0	0	1
Corporate Segment [Member]
Restructuring Reserve [Roll Forward]
Restructuring expense	$ 1	$ 0	$ 1	$ 1
Scenario, Forecast [Member]
Restructuring Reserve [Roll Forward]
Expected fiscal year restructuring expense					$ 80