Impairment of Long-Lived Assets (Details) - USD ($) $ in Millions	12 Months Ended			24 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020
Impairment of Long Lived Assets [Line Items]
Asset Impairment Charges	$ 98	$ 582	$ 235
Impairment of Long-Lived Assets Held-for-use	98	81
Building Solutions Asia Pacific
Impairment of Long Lived Assets [Line Items]
Impairment of Long-Lived Assets Held-for-use	4	24
Building Solutions EMEA/LA
Impairment of Long Lived Assets [Line Items]
Impairment of Long-Lived Assets Held-for-use	5
Building Solutions North America
Impairment of Long Lived Assets [Line Items]
Impairment of Long-Lived Assets Held-for-use	33	15
Global Products
Impairment of Long Lived Assets [Line Items]
Impairment of Long-Lived Assets to be Disposed of		15	$ 235	$ 250
Impairment of Long-Lived Assets Held-for-use	50	$ 42
Corporate
Impairment of Long Lived Assets [Line Items]
Impairment of Long-Lived Assets Held-for-use	$ 6