Restructuring and Impairment Costs (Details) $ in Millions	3 Months Ended
	Dec. 31, 2019 USD ($) plant employee	Dec. 31, 2018 USD ($)	Sep. 30, 2019 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment costs	$ 2	$ 31
Restructuring reserve	$ 109		$ 123
Number of positions eliminated to date | employee	8,900
Number of positions eliminated | employee	6,200
Number of plants expected to close | plant	18
Number of plants closed | plant	15
2020 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment costs	$ 7
Restructuring reserve accrual adjustment	5
Restructuring reserve	5		7
2020 Restructuring Plan | Employee Severance and Termination Benefits
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	5		6
2020 Restructuring Plan | Asia
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment costs	2
2020 Restructuring Plan | Americas
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment costs	3
2020 Restructuring Plan | EMEA
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment costs	2
2019 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring reserve accrual adjustment	1
Restructuring reserve	60		70
2019 Restructuring Plan | Employee Severance and Termination Benefits
Restructuring Cost and Reserve [Line Items]
Restructuring reserve accrual adjustment	2
Restructuring reserve	58		69
2018 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring reserve accrual adjustment	2
Restructuring reserve	13		20
2018 Restructuring Plan | Employee Severance and Termination Benefits
Restructuring Cost and Reserve [Line Items]
Restructuring reserve accrual adjustment	3
Restructuring reserve	16		$ 24
2017 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	$ 5