RESTRUCTURING COSTS - Schedule of Restructuring Reserve by Type of Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Restructuring Costs [Roll Forward]
Restructuring reserve, beginning balance	$ 112	$ 87
Expense	136	228	$ 72
Utilized/Paid	128	203
Restructuring reserve, ending balance	120	112	87
Severance and benefits
Restructuring Costs [Roll Forward]
Restructuring reserve, beginning balance	105	85
Expense	120	191
Utilized/Paid	109	171
Restructuring reserve, ending balance	116	105	85
Other
Restructuring Costs [Roll Forward]
Restructuring reserve, beginning balance	7	2
Expense	16	37
Utilized/Paid	19	32
Restructuring reserve, ending balance	$ 4	$ 7	$ 2