COLLATERALIZED AGREEMENTS AND FINANCINGS, Schedule of Offsetting Transactions (Details) - USD ($) $ in Millions	Sep. 30, 2024	Sep. 30, 2023
Reverse repurchase agreements
Gross amounts of recognized assets/liabilities	$ 413	$ 187
Gross amounts offset on the Consolidated Statements of Financial Condition	0	0
Net amounts included in the Consolidated Statements of Financial Condition	413	187
Gross amounts not offset on the Consolidated Statements of Financial Condition	(413)	(187)
Net amounts	0	0
Securities borrowed
Gross amounts of recognized assets/liabilities	336	231
Gross amounts offset on the Consolidated Statements of Financial Condition	0	0
Net amounts included in the Consolidated Statements of Financial Condition	336	231
Gross amounts not offset on the Consolidated Statements of Financial Condition	(326)	(224)
Net amounts	10	7
Gross amounts of recognized assets/liabilities	749	418
Gross amounts offset on the Consolidated Statements of Financial Condition	0	0
Net amounts included in the Consolidated Statements of Financial Condition	749	418
Gross amounts not offset on the Consolidated Statements of Financial Condition	(739)	(411)
Net amounts	10	7
Repurchase agreements
Gross amounts of recognized assets/liabilities	402	157
Gross amounts offset on the Consolidated Statements of Financial Condition	0	0
Net amounts included in the Consolidated Statements of Financial Condition	402	157
Gross amounts not offset on the Consolidated Statements of Financial Condition	(402)	(157)
Net amounts	0	0
Securities loaned
Gross amounts of recognized assets/liabilities	536	180
Gross amounts offset on the Consolidated Statements of Financial Condition	0	0
Net amounts included in the Consolidated Statements of Financial Condition	536	180
Gross amounts not offset on the Consolidated Statements of Financial Condition	(522)	(173)
Net amounts	14	7
Gross amounts of recognized assets/liabilities	938	337
Gross amounts offset on the Consolidated Statements of Financial Condition	0	0
Net amounts included in the Consolidated Statements of Financial Condition	938	337
Gross amounts not offset on the Consolidated Statements of Financial Condition	(924)	(330)
Net amounts	$ 14	$ 7