BANK DEPOSITS, Summary of Interest Expense on Deposits (Details) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Deposits [Abstract]
Money market and savings accounts	$ 527	$ 78	$ 3
Interest-bearing demand deposits	469	38	3
Certificates of deposit	84	15	17
Total interest expense on deposits	$ 1,080	$ 131	$ 23

No definition available.

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- Definition

Aggregate amount of interest expense on all deposits.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.6)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1

+ Details

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- Definition

Amount of interest expense on domestic checking deposit liabilities.

+ References

+ Details

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- Definition

The aggregate interest expense incurred on the following for deposits in domestic offices: (1) transaction accounts (NOW, and telephone and preauthorized transfer accounts), (2) money market deposits and (3) savings deposits.

+ References

+ Details

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- Definition

The aggregate interest expense incurred on time deposits, including certificates of deposits, in domestic offices.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1402
-Paragraph (a)
-Publisher SEC

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1402
-Paragraph (b)
-Subparagraph (1)
-Publisher SEC

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.6)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483589/942-220-S99-1

+ Details

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