LEASES - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Leases [Abstract]
Cash paid for operating leases, operating cash flows	$ 190	$ 202	$ 170
Operating lease right-of-use asset additions	$ 141	$ 250	$ 247
Operating leases, weighted-average remaining term	7 years 3 months 18 days	7 years 8 months 12 days
Operating leases, weighted-average discount rate	4.40%	4.40%