COLLATERALIZED AGREEMENTS AND FINANCINGS, Schedule of Offsetting Transactions (Details) - USD ($) $ in Millions	Sep. 30, 2021	Sep. 30, 2020
Reverse repurchase agreements
Gross amounts of recognized assets/liabilities	$ 279	$ 207
Gross amounts offset on the Consolidated Statements of Financial Condition	0	0
Net amounts presented on the Consolidated Statements of Financial Condition	279	207
Gross amounts not offset on the Consolidated Statements of Financial Condition	(279)	(207)
Net amounts	0	0
Securities borrowed
Gross amounts of recognized assets/liabilities	201	215
Gross amounts offset on the Consolidated Statements of Financial Condition	0	0
Net amounts presented on the Consolidated Statements of Financial Condition	201	215
Gross amounts not offset on the Consolidated Statements of Financial Condition	(195)	(209)
Net amounts	6	6
Assets, Total
Gross amounts of recognized assets/liabilities	480	422
Gross amounts offset on the Consolidated Statements of Financial Condition	0	0
Net amounts presented on the Consolidated Statements of Financial Condition	480	422
Gross amounts not offset on the Consolidated Statements of Financial Condition	(474)	(416)
Net amounts	6	6
Repurchase agreements
Gross amounts of recognized assets/liabilities	205	165
Gross amounts offset on the Consolidated Statements of Financial Condition	0	0
Net amounts presented on the Consolidated Statements of Financial Condition	205	165
Gross amounts not offset on the Consolidated Statements of Financial Condition	(205)	(165)
Net amounts	0	0
Securities loaned
Gross amounts of recognized assets/liabilities	72	85
Gross amounts offset on the Consolidated Statements of Financial Condition	0	0
Net amounts presented on the Consolidated Statements of Financial Condition	72	85
Gross amounts not offset on the Consolidated Statements of Financial Condition	(68)	(79)
Net amounts	4	6
Liabilities, Total
Gross amounts of recognized assets/liabilities	277	250
Gross amounts offset on the Consolidated Statements of Financial Condition	0	0
Net amounts presented on the Consolidated Statements of Financial Condition	277	250
Gross amounts not offset on the Consolidated Statements of Financial Condition	(273)	(244)
Net amounts	$ 4	$ 6