Income Taxes - Income Before Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Domestic	$ 362	$ 647	$ 424
Foreign	1,025	1,342	243
Income before income taxes	$ 1,387	$ 1,989	$ 667