Income Taxes - Schedule of Principal Components of Income Tax Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Current:
U.S. federal	$ 465	$ 315	$ 17
State and local	47	36	14
Non-U.S.	369	306	258
Deferred:
U.S. federal	(198)	(92)	84
State and local	(23)	(13)	(2)
Non-U.S.	(61)	(3)	(25)
Income tax expense	$ 599	$ 549	$ 346