PENSION AND POSTRETIREMENT PLANS - Reconciliations of Actuarial Present Value of Projected Benefit Obligations and Fair Value of Plan Assets for Defined Benefit Pension Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Change in fair value of plan assets [Roll Forward]
Noncurrent asset	$ 1,229	$ 1,194
Pension Plan
Change in fair value of plan assets [Roll Forward]
Fair value of plan assets, beginning	4,855
Fair value of plan assets, ending	4,705	4,855
U.S. Plans | Pension Plan
Change in projected benefit obligation [Roll Forward]
Projected benefit obligation, beginning	3,089	2,934
Service cost	50	17	$ 25
Interest cost	140	169	164
Actuarial (gain) loss	(80)	283
Curtailments	0	(4)
Benefits paid	(227)	(205)
Settlements	(43)	(108)
Acquisitions (Divestitures), net	0	0
Foreign currency translation and other	0	3
Projected benefit obligation, ending	2,929	3,089	2,934
Change in fair value of plan assets [Roll Forward]
Fair value of plan assets, beginning	3,889	3,590
Actual return on plan assets	151	598
Employer contributions	15	14
Benefits paid	(227)	(205)
Settlements	(43)	(108)
Acquisitions (Divestitures), net	0	0
Foreign currency translation and other	0	0
Fair value of plan assets, ending	3,785	3,889	3,590
Net amount recognized in the balance sheet	856	800
Noncurrent asset	1,017	961
Current liability	(14)	(14)
Noncurrent liability	(147)	(147)
Pretax accumulated other comprehensive loss	(242)	(243)
Non-U.S. Plans | Pension Plan
Change in projected benefit obligation [Roll Forward]
Projected benefit obligation, beginning	1,004	926
Service cost	22	20	20
Interest cost	46	49	50
Actuarial (gain) loss	(24)	13
Curtailments	(4)	0
Benefits paid	(40)	(41)
Settlements	(35)	(39)
Acquisitions (Divestitures), net	0	6
Foreign currency translation and other	16	70
Projected benefit obligation, ending	985	1,004	926
Change in fair value of plan assets [Roll Forward]
Fair value of plan assets, beginning	966	864
Actual return on plan assets	(11)	73
Employer contributions	31	24
Benefits paid	(40)	(41)
Settlements	(35)	(39)
Acquisitions (Divestitures), net	0	(2)
Foreign currency translation and other	9	87
Fair value of plan assets, ending	920	966	$ 864
Net amount recognized in the balance sheet	(65)	(38)
Noncurrent asset	212	233
Current liability	(18)	(17)
Noncurrent liability	(259)	(254)
Pretax accumulated other comprehensive loss	$ (187)	$ (163)