Business Restructuring Charges - Changes in Restructuring Balance (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Restructuring Reserve [Roll Forward]
Beginning balance	$ 19	$ 36	$ 57
Charged to expense	123	44	84
Cash payments	(82)	(56)	(80)
Non-cash settlements	(25)	(4)	(26)
Other adjustments	1
Ending balance	35	19	36
Employee Termination
Restructuring Reserve [Roll Forward]
Beginning balance	14	32	53
Charged to expense	21	14	20
Cash payments	(11)	(31)	(41)
Non-cash settlements	0	0	0
Other adjustments	0
Ending balance	24	14	32
Other
Restructuring Reserve [Roll Forward]
Beginning balance	5	4	4
Charged to expense	103	30	65
Cash payments	(71)	(25)	(39)
Non-cash settlements	(25)	(4)	(26)
Other adjustments	1
Ending balance	$ 11	$ 5	$ 4