COLLATERALIZED AGREEMENTS AND FINANCINGS, Schedule of Offsetting Transactions (Details) - USD ($) $ in Millions	Dec. 31, 2021	Sep. 30, 2021
Reverse repurchase agreements
Gross amounts of recognized assets/liabilities	$ 204	$ 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	204	279
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(204)	(279)
Net amounts	0	0
Securities borrowed
Gross amounts of recognized assets/liabilities	143	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	143	201
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(139)	(195)
Net amounts	4	6
Gross amounts of recognized assets/liabilities	347	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	347	480
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(343)	(474)
Net amounts	4	6
Repurchase agreements
Gross amounts of recognized assets/liabilities	203	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	203	205
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(203)	(205)
Net amounts	0	0
Securities loaned
Gross amounts of recognized assets/liabilities	65	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	65	72
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(62)	(68)
Net amounts	3	4
Gross amounts of recognized assets/liabilities	268	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	268	277
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(265)	(273)
Net amounts	$ 3	$ 4