Restructuring and Impairment Costs - Narrative (Details) employee in Thousands, $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Jun. 30, 2021 USD ($) employee	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) employee plant	Jun. 30, 2020 USD ($)	Sep. 30, 2020 USD ($)
Restructuring Cost and Reserve [Line Items]
Noncash adjustment—underspend/other					$ 20
Restructuring and impairment costs	$ 8	$ 49	$ 20	$ 103
Restructuring reserve	$ 135		$ 135		237
Number of positions eliminated to date | employee	18		18
Number of positions eliminated | employee			14
Number of plants expected to close | plant			25
Number of plants closed | plant			19
2021 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Expected restructuring costs	$ 24		$ 24
Noncash adjustment—underspend/other			14
Utilized—cash			2
Restructuring reserve	22		22		24
2021 Restructuring Plan | EMEA
Restructuring Cost and Reserve [Line Items]
Expected restructuring costs	23		23
2021 Restructuring Plan | Asia
Restructuring Cost and Reserve [Line Items]
Expected restructuring costs	1		1
2020 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Noncash adjustment—underspend/other			0
Restructuring and impairment costs					205
Utilized—cash			77
Restructuring reserve	92		92		169
2020 Restructuring Plan | EMEA
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment costs					175
2020 Restructuring Plan | Asia
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment costs					10
2020 Restructuring Plan | Americas
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment costs					$ 20
Restructuring Plan 2018, 2017, 2016
Restructuring Cost and Reserve [Line Items]
Utilized—cash			18
2018 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	4		4
2017 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	3		3
2016 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	$ 2		$ 2