VARIABLE INTEREST ENTITIES, Primary Beneficiary - Aggregate Assets and Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2024	Sep. 30, 2023
Variable interest entity, consolidated, aggregate assets and liabilities [Abstract]
Aggregate assets	$ 82,992	$ 78,360
Aggregate liabilities	71,325	68,173
Variable Interest Entity, Primary Beneficiary
Variable interest entity, consolidated, aggregate assets and liabilities [Abstract]
Aggregate assets	155	71
Aggregate liabilities	79	26
Variable Interest Entity, Primary Beneficiary | LIHTC funds
Variable interest entity, consolidated, aggregate assets and liabilities [Abstract]
Aggregate assets	136	51
Aggregate liabilities	60	6
Variable Interest Entity, Primary Beneficiary | Restricted Stock Trust Fund
Variable interest entity, consolidated, aggregate assets and liabilities [Abstract]
Aggregate assets	19	20
Aggregate liabilities	$ 19	$ 20