Income Taxes - Narrative (Details) $ in Millions	12 Months Ended
	Sep. 30, 2024 USD ($) component	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)
Income Tax Contingency [Line Items]
Foreign tax rate differential	$ 9	$ 22	$ (1)
Tax rate differential from mix of income and losses in the significant jurisdictions	20	33	9
Tax from nonconsolidated partially owned affiliates	11	11	8
Net operating loss carryforwards	4,700
Net operating loss carryforwards set to expire between 2025 and 2044	2,400
Operating loss carryforwards, valuation allowance	3,400
Unrecognized tax benefits	422	527	499	$ 499
Unrecognized tax benefits that would impact effective tax rate	106
Net accrued interest	21	31	22
Settlements with taxing authorities	115	11	3
Benefit from settlements with taxing authorities	63
Unremitted earnings of foreign subsidiaries	39	38
Income taxes paid	96	94	77
Income tax provision	$ 32	0	94
Number of components | component	2
Receita Federal do Brasil
Income Tax Contingency [Line Items]
Tax adjustments			32
Income tax provision			4
Foreign tax authority
Income Tax Contingency [Line Items]
Increase in valuation allowance	$ 38
Foreign tax authority | State Administration of Taxation, China
Income Tax Contingency [Line Items]
Decrease in valuation allowance	14
Foreign tax authority | Mexico
Income Tax Contingency [Line Items]
Decrease in valuation allowance	8
Increase in valuation allowance	5
Deferred tax asset, release of valuation allowance		$ 114
Foreign tax authority | Ministry of the Economy, Finance and Industry, France
Income Tax Contingency [Line Items]
Decrease in valuation allowance	7
Foreign tax authority | Japan
Income Tax Contingency [Line Items]
Decrease in valuation allowance	6
Increase in valuation allowance			3
Foreign tax authority | National Revenue Administration, Poland
Income Tax Contingency [Line Items]
Increase in valuation allowance	$ 14
Foreign tax authority | Canada
Income Tax Contingency [Line Items]
Increase in valuation allowance			12
Foreign tax authority | Other Jurisdictions
Income Tax Contingency [Line Items]
Decrease in valuation allowance			2
Increase in valuation allowance			3
Foreign tax authority | Czech Tax Authority
Income Tax Contingency [Line Items]
Decrease in valuation allowance			$ 11