Benefit Plans - Change in Benefit Obligation, Change in Fair Value of Plan Assets (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Amounts recognized in the Consolidated Balance Sheets at September 30:
Long-term Employee Benefit Obligations	$ (1,023)	$ (902)
Pension Plans
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning obligation	2,634	3,889
Service cost	91	134	$ 150
Interest cost	129	77	71
Plan amendments	0	1
Benefits paid	(67)	(64)
Impact of Embecta spin-off	0	(7)
Actuarial gain	(24)	(1,007)
Curtailments/settlements	(214)	(246)
Other, includes translation	68	(143)
Ending obligation	2,617	2,634	3,889
Change in fair value of plan assets:
Beginning fair value	2,242	3,222
Actual return on plan assets	33	(740)
Employer contribution	62	198
Benefits paid	(67)	(64)
Impact of Embecta spin-off	0	(6)
Settlements	(200)	(241)
Other, includes translation	59	(127)
Ending fair value	2,129	2,242	$ 3,222
Funded Status at September 30:
Unfunded benefit obligation	(488)	(392)
Amounts recognized in the Consolidated Balance Sheets at September 30:
Other Assets	81	70
Salaries, wages and related items	(15)	(15)
Long-term Employee Benefit Obligations	(554)	(447)
Net amount recognized	(488)	(392)
Amounts recognized in Accumulated other comprehensive income (loss) before income taxes at September 30:
Prior service credit	3	24
Net actuarial loss	(689)	(728)
Net amount recognized	$ (686)	$ (704)