SHORT-TERM BORROWINGS AND LINES OF CREDIT - Narrative (Details) - USD ($) $ in Millions	Feb. 11, 2025	Sep. 30, 2025	Sep. 30, 2024
Debt Instrument [Line Items]
Commercial paper		$ 4,192	$ 0
Revolving Credit Facility | 364-Day Revolving Backup Credit Facility | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 3,000
Debt instrument, term	364 days
Revolving Credit Facility | Five Year Revolving Backup Credit Facility | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 3,500
Debt instrument, term	5 years