Supplemental Financial Information - Other Income (Expense), Net (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Equity Securities, FV-NI, Unrealized Gain (Loss)		$ 57	$ 13	$ 18
Foreign Currency Transaction Gain (Loss), Realized		(13)	(17)	(23)
Losses on debt extinguishment	$ (1)	(178)	(8)	(59)
Royalty Income, Nonoperating		0	17	64
Insurance Recoveries		0	0	35
Other Nonoperating Income		(3)	(3)	4
Other Nonoperating Income (Expense)		(97)	23	43
Other Nonoperating Income (Expense)
Deferred Compensation Investment Income (Expense)		43	24	6
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)		(1)	7	(2)
Gains (Losses) on Product Related Matters		$ (2)	$ (9)	$ 0