VARIABLE INTEREST ENTITIES, Primary Beneficiary - Aggregate Assets and Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2025	Sep. 30, 2024
Variable interest entity, consolidated, aggregate assets and liabilities [Abstract]
Aggregate assets	$ 84,815	$ 82,992
Aggregate liabilities	72,554	71,325
Variable Interest Entity, Primary Beneficiary
Variable interest entity, consolidated, aggregate assets and liabilities [Abstract]
Aggregate assets	117	155
Aggregate liabilities	61	79
Variable Interest Entity, Primary Beneficiary \| LIHTC funds
Variable interest entity, consolidated, aggregate assets and liabilities [Abstract]
Aggregate assets	89	136
Aggregate liabilities	33	60
Variable Interest Entity, Primary Beneficiary \| Restricted Stock Trust Fund
Variable interest entity, consolidated, aggregate assets and liabilities [Abstract]
Aggregate assets	28	19
Aggregate liabilities	$ 28	$ 19

Amount of asset recognized for present right to economic benefit.

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+ Details

- Definition

Amount of liability recognized for present obligation requiring transfer or otherwise providing economic benefit to others.

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+ Details