DERIVATIVE ASSETS AND DERIVATIVE LIABILITIES, Derivative Assets and Liability Fair Value (Details) - USD ($) $ in Millions	Jun. 30, 2022	Sep. 30, 2021
Derivative assets
Derivative assets	$ 387	$ 342
Counterparty netting	(31)	(46)
Cash collateral netting	(204)	(41)
Total amounts offset	(235)	(87)
Derivative assets	152	255
Financial instruments	(85)	(205)
Net amount	67	50
Derivative liabilities
Derivative liabilities	437	316
Counterparty netting	(31)	(46)
Cash collateral netting	(27)	(42)
Total amounts offset	(58)	(88)
Net amounts presented on the Condensed Consolidated Statements of Financial Condition	379	228
Financial instruments	(84)	(193)
Net amount	295	35
Notional amount	21,739	19,989
Derivatives not designated as hedging instruments
Derivative assets
Derivative assets	376	340
Derivative liabilities
Derivative liabilities	437	316
Notional amount	19,529	18,200
Derivatives not designated as hedging instruments | Interest rate - matched book
Derivative assets
Interest rate - matched book	84	193
Derivative liabilities
Interest rate - matched book	84	193
Notional amount	1,340	1,736
Derivatives not designated as hedging instruments | Interest rate - other
Derivative assets
Derivative assets	288	144
Derivative liabilities
Derivative liabilities	352	122
Notional amount	16,551	15,087
Derivatives not designated as hedging instruments | Foreign exchange
Derivative assets
Derivative assets	2	3
Derivative liabilities
Derivative liabilities	0	0
Notional amount	1,037	826
Derivatives not designated as hedging instruments | Other
Derivative assets
Derivative assets	2	0
Derivative liabilities
Derivative liabilities	1	1
Notional amount	601	551
Derivatives designated as hedging instruments
Derivative assets
Derivative assets	11	2
Derivative liabilities
Derivative liabilities	0	0
Notional amount	2,210	1,789
Derivatives designated as hedging instruments | Interest rate - other
Derivative assets
Derivative assets	9	0
Derivative liabilities
Derivative liabilities	0	0
Notional amount	1,050	850
Derivatives designated as hedging instruments | Foreign exchange
Derivative assets
Derivative assets	2	2
Derivative liabilities
Derivative liabilities	0	0
Notional amount	$ 1,160	$ 939