BANK DEPOSITS, Bank Deposits by Insured and Uninsured (Details) - USD ($) $ in Millions	Jun. 30, 2023	Sep. 30, 2022
Deposits [Abstract]
FDIC-insured bank deposits	$ 46,884	$ 43,520
Bank deposits exceeding FDIC insurance limit	6,884	7,837
Total bank deposits	$ 53,768	$ 51,357
FDIC-insured bank deposits as a % of total bank deposits	87.00%	85.00%

The aggregate of all deposit liabilities held by the entity, including foreign and domestic, interest and noninterest bearing; may include demand deposits, saving deposits, Negotiable Order of Withdrawal (NOW) and time deposits among others.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.12)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1

Name:	us-gaap_Deposits
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant