STOCK-BASED COMPENSATION - Schedule of Supplemental Information for Incentive Awards (Details) - Incentive Shares Member - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total fair value of shares earned/vested (in shares)	$ 256	$ 284	$ 158
Share awards distributed in cash, primarily for tax withholding (in shares)	$ 59	$ 81	$ 73