COLLATERALIZED AGREEMENTS AND FINANCINGS, Schedule of Offsetting Transactions (Details) - USD ($) $ in Millions	Jun. 30, 2023	Sep. 30, 2022
Reverse repurchase agreements
Gross amounts of recognized assets/liabilities	$ 181	$ 367
Gross amounts offset on the Condensed Consolidated Statements of Financial Condition	0	0
Net amounts included in the Condensed Consolidated Statements of Financial Condition	181	367
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(181)	(367)
Net amounts	0	0
Securities borrowed
Gross amounts of recognized assets/liabilities	229	337
Gross amounts offset on the Condensed Consolidated Statements of Financial Condition	0	0
Net amounts included in the Condensed Consolidated Statements of Financial Condition	229	337
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(223)	(327)
Net amounts	6	10
Gross amounts of recognized assets/liabilities	410	704
Gross amounts offset on the Condensed Consolidated Statements of Financial Condition	0	0
Net amounts included in the Condensed Consolidated Statements of Financial Condition	410	704
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(404)	(694)
Net amounts	6	10
Repurchase agreements
Gross amounts of recognized assets/liabilities	110	294
Gross amounts offset on the Condensed Consolidated Statements of Financial Condition	0	0
Net amounts included in the Condensed Consolidated Statements of Financial Condition	110	294
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(110)	(294)
Net amounts	0	0
Securities loaned
Gross amounts of recognized assets/liabilities	71	172
Gross amounts offset on the Condensed Consolidated Statements of Financial Condition	0	0
Net amounts included in the Condensed Consolidated Statements of Financial Condition	71	172
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(68)	(162)
Net amounts	3	10
Gross amounts of recognized assets/liabilities	181	466
Gross amounts offset on the Condensed Consolidated Statements of Financial Condition	0	0
Net amounts included in the Condensed Consolidated Statements of Financial Condition	181	466
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(178)	(456)
Net amounts	$ 3	$ 10