Income Taxes - Components of Income from Continuing Operations Before Income Taxes (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Domestic, including Puerto Rico	$ 133	$ (489)	$ 799
Foreign	2,109	1,474	377
Income Before Income Taxes	$ 2,242	$ 985	$ 1,176