COMMITMENTS, CONTINGENCIES AND GUARANTEES, Summary of Commitments to Extend Credit and Other Credit-Related Off-Balance Sheet Financial Instruments Outstanding (Details) - USD ($) $ in Millions	Dec. 31, 2022	Sep. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Open-end consumer lines of credit (primarily SBL)	$ 35,159	$ 33,641
Commercial lines of credit	3,809	3,792
Unfunded loan commitments	1,227	1,255
Standby letters of credit	$ 99	$ 94