Other Income (Expense), Net Other Income (Expense), Net (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Other Income (Expense), Net
Interest income	$ 52	$ 42	$ 34
External services	28	17	15
Gain (Loss) on Investments	14	23	13
Miscellaneous	(2)	(11)	(1)
Other income (expense), net	$ 92	$ 71	$ 61