COLLATERALIZED AGREEMENTS AND FINANCINGS, Schedule of Offsetting Transactions (Details) - USD ($) $ in Millions	Jun. 30, 2022	Sep. 30, 2021
Reverse repurchase agreements
Gross amounts of recognized assets/liabilities	$ 168	$ 279
Gross amounts offset on the Condensed Consolidated Statements of Financial Condition	0	0
Net amounts presented on the Condensed Consolidated Statements of Financial Condition	168	279
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(168)	(279)
Net amounts	0	0
Securities borrowed
Gross amounts of recognized assets/liabilities	463	201
Gross amounts offset on the Condensed Consolidated Statements of Financial Condition	0	0
Net amounts presented on the Condensed Consolidated Statements of Financial Condition	463	201
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(452)	(195)
Net amounts	11	6
Gross amounts of recognized assets/liabilities	631	480
Gross amounts offset on the Condensed Consolidated Statements of Financial Condition	0	0
Net amounts presented on the Condensed Consolidated Statements of Financial Condition	631	480
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(620)	(474)
Net amounts	11	6
Repurchase agreements
Gross amounts of recognized assets/liabilities	100	205
Gross amounts offset on the Condensed Consolidated Statements of Financial Condition	0	0
Net amounts presented on the Condensed Consolidated Statements of Financial Condition	100	205
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(100)	(205)
Net amounts	0	0
Securities loaned
Gross amounts of recognized assets/liabilities	337	72
Gross amounts offset on the Condensed Consolidated Statements of Financial Condition	0	0
Net amounts presented on the Condensed Consolidated Statements of Financial Condition	337	72
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(320)	(68)
Net amounts	17	4
Gross amounts of recognized assets/liabilities	437	277
Gross amounts offset on the Condensed Consolidated Statements of Financial Condition	0	0
Net amounts presented on the Condensed Consolidated Statements of Financial Condition	437	277
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(420)	(273)
Net amounts	$ 17	$ 4