OTHER ASSETS (Details) - USD ($) $ in Millions	Dec. 31, 2023	Sep. 30, 2023
Prepaid Expense and Other Assets [Abstract]
Investments in company-owned life insurance policies	$ 1,228	$ 1,110
Property and equipment, net	580	561
Lease right-of-use (“ROU”) assets	552	560
Prepaid expenses	257	209
Investments in FHLB and FRB stock	114	114
Client-owned fractional shares	110	98
All other	219	141
Total other assets	$ 3,060	$ 2,793