Nonconsolidated Partially-Owned Affiliates - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2025	Sep. 30, 2024
Schedule of Equity Method Investments [Line Items]
Investments in partially-owned affiliates		$ 276	$ 338
Asia
Schedule of Equity Method Investments [Line Items]
Non-cash impairment charges	$ 3
EMEA
Schedule of Equity Method Investments [Line Items]
Non-cash impairment charges	$ 3