Debt and Financing Arrangements - Long-term Debt (Details) € in Millions, $ in Millions	12 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Aug. 30, 2024 USD ($)	Aug. 30, 2024 EUR (€)	Oct. 31, 2023
Debt Instrument [Line Items]
Less: debt issuance costs	$ (28)	$ (31)
Gross long-term debt	2,404	2,533
Less: current portion	8	132
Long-term debt	2,396	2,401
Short-term debt:
Short-term debt	$ 1	$ 2
Weighted average interest rate on short-term debt outstanding (as percent)	5.40%	10.10%
Term Loan B due in 2031
Debt Instrument [Line Items]
Long-term debt, gross	$ 632	$ 635
Other bank borrowings
Short-term debt:
Short-term debt	$ 1	2
Unsecured debt | 8.25% Notes due 2031
Debt Instrument [Line Items]
Interest rate	8.25%
Long-term debt, gross	$ 500	500
Unsecured debt | 4.875% Notes due in 2026
Debt Instrument [Line Items]
Interest rate	4.875%
Long-term debt, gross	$ 795	$ 795
Unsecured debt | 3.50% Notes due in 2024
Debt Instrument [Line Items]
Interest rate	3.50%	3.50%			3.50%
Long-term debt, gross	$ 0	$ 130	$ 132	€ 123
Unsecured debt | Other bank borrowings and finance lease obligations
Debt Instrument [Line Items]
Long-term debt, gross	$ 5	4
Term loan | 7.00% Secured Notes due 2028
Debt Instrument [Line Items]
Interest rate	7.00%
Long-term debt, gross	$ 500	$ 500