DERIVATIVE ASSETS AND DERIVATIVE LIABILITIES, Derivative Asset and Liability Fair Value (Details) - USD ($) $ in Millions	Sep. 30, 2024	Sep. 30, 2023
Derivative assets
Derivative assets	$ 349	$ 526
Counterparty netting	(86)	(29)
Cash collateral netting	(160)	(232)
Total amounts offset	(246)	(261)
Net amounts presented on the Consolidated Statements of Financial Condition	103	265
Financial instruments	(5)	(131)
Net amount	98	134
Derivative liabilities
Derivative liabilities	347	578
Counterparty netting	(86)	(29)
Cash collateral netting	(37)	(59)
Total amounts offset	(123)	(88)
Net amounts presented on the Consolidated Statements of Financial Condition	224	490
Financial instruments	0	0
Net amount	224	490
Notional amount	25,159	22,441
Derivatives not designated as hedging instruments
Derivative assets
Derivative assets	342	513
Derivative liabilities
Derivative liabilities	347	578
Notional amount	22,683	20,069
Derivatives not designated as hedging instruments | Interest rate
Derivative assets
Derivative assets	336	509
Derivative liabilities
Derivative liabilities	346	576
Notional amount	20,629	18,270
Derivatives not designated as hedging instruments | Foreign exchange
Derivative assets
Derivative assets	2	4
Derivative liabilities
Derivative liabilities	1	2
Notional amount	949	1,191
Derivatives not designated as hedging instruments | Other
Derivative assets
Derivative assets	4	0
Derivative liabilities
Derivative liabilities	0	0
Notional amount	1,105	608
Derivatives designated as hedging instruments
Derivative assets
Derivative assets	7	13
Derivative liabilities
Derivative liabilities	0	0
Notional amount	2,476	2,372
Derivatives designated as hedging instruments | Interest rate
Derivative assets
Derivative assets	2	8
Derivative liabilities
Derivative liabilities	0	0
Notional amount	1,250	1,200
Derivatives designated as hedging instruments | Foreign exchange
Derivative assets
Derivative assets	5	5
Derivative liabilities
Derivative liabilities	0	0
Notional amount	$ 1,226	$ 1,172