COLLATERALIZED AGREEMENTS AND FINANCINGS, Schedule of Offsetting Transactions (Details) - USD ($) $ in Millions	Dec. 31, 2023	Sep. 30, 2023
Reverse repurchase agreements
Gross amounts of recognized assets/liabilities	$ 194	$ 187
Gross amounts offset on the Condensed Consolidated Statements of Financial Condition	0	0
Net amounts included in the Condensed Consolidated Statements of Financial Condition	194	187
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(194)	(187)
Net amounts	0	0
Securities borrowed
Gross amounts of recognized assets/liabilities	260	231
Gross amounts offset on the Condensed Consolidated Statements of Financial Condition	0	0
Net amounts included in the Condensed Consolidated Statements of Financial Condition	260	231
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(248)	(224)
Net amounts	12	7
Gross amounts of recognized assets/liabilities	454	418
Gross amounts offset on the Condensed Consolidated Statements of Financial Condition	0	0
Net amounts included in the Condensed Consolidated Statements of Financial Condition	454	418
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(442)	(411)
Net amounts	12	7
Repurchase agreements
Gross amounts of recognized assets/liabilities	169	157
Gross amounts offset on the Condensed Consolidated Statements of Financial Condition	0	0
Net amounts included in the Condensed Consolidated Statements of Financial Condition	169	157
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(169)	(157)
Net amounts	0	0
Securities loaned
Gross amounts of recognized assets/liabilities	347	180
Gross amounts offset on the Condensed Consolidated Statements of Financial Condition	0	0
Net amounts included in the Condensed Consolidated Statements of Financial Condition	347	180
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(332)	(173)
Net amounts	15	7
Gross amounts of recognized assets/liabilities	516	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	516	337
Gross amounts not offset on the Condensed Consolidated Statements of Financial Condition	(501)	(330)
Net amounts	$ 15	$ 7