Other Operating Income, Net and Other Non-Operating Income (Expense), Net - Schedule of Other Non-Operating (Expense) Income, Net (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Component of Operating Income [Abstract]
(Losses) gains on foreign currency contracts, net	$ (19)	$ (23)	$ 63
Amortization of excluded components of certain net investment hedges	5	7	7
Pension and other postretirement plans non-service income, net	6	9	5
Total other non-operating (expense) income, net	$ (8)	$ (7)	$ 75