DERIVATIVE ASSETS AND DERIVATIVE LIABILITIES, Income Statement Location (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on derivatives	$ 15	$ 11	$ 20
Foreign exchange
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on derivatives	13	(21)	(23)
Gains/(losses) on derivatives, net of gains/(losses) on related hedged item	10	7	6
Other
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(losses) on derivatives	$ (4)	$ 4	$ 2