Business Restructuring Charges - Changes in Restructuring Balance (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Restructuring Reserve [Roll Forward]
Beginning balance	$ 35	$ 19	$ 36
Charged to expense	239	123	44
Cash payments	(165)	(82)	(56)
Non-cash settlements	(30)	(25)	(4)
Other adjustments	1	(1)
Ending balance	80	35	19
Employee Termination
Restructuring Reserve [Roll Forward]
Beginning balance	24	14	32
Charged to expense	117	21	14
Cash payments	(62)	(11)	(31)
Non-cash settlements	0	0	0
Other adjustments	0	0
Ending balance	79	24	14
Other
Restructuring Reserve [Roll Forward]
Beginning balance	11	5	4
Charged to expense	122	103	30
Cash payments	(103)	(71)	(25)
Non-cash settlements	(30)	(25)	(4)
Other adjustments	1	(1)
Ending balance	$ 1	$ 11	$ 5