VARIABLE INTEREST ENTITIES VARIABLE INTEREST ENTITIES, Primary Beneficiary - Aggregate Assets and Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2020	Sep. 30, 2019
Variable interest entity, consolidated, aggregate assets and liabilities [Abstract]
Aggregate assets	$ 47,482	$ 38,830
Aggregate liabilities	40,306	32,187
Variable Interest Entity, Primary Beneficiary
Variable interest entity, consolidated, aggregate assets and liabilities [Abstract]
Aggregate assets	221	159
Aggregate liabilities	94	23
Private Equity Interests | Variable Interest Entity, Primary Beneficiary
Variable interest entity, consolidated, aggregate assets and liabilities [Abstract]
Aggregate assets	39	65
Aggregate liabilities	4	4
LIHTC funds | Variable Interest Entity, Primary Beneficiary
Variable interest entity, consolidated, aggregate assets and liabilities [Abstract]
Aggregate assets	168	80
Aggregate liabilities	76	5
Restricted Stock Trust Fund | Variable Interest Entity, Primary Beneficiary
Variable interest entity, consolidated, aggregate assets and liabilities [Abstract]
Aggregate assets	14	14
Aggregate liabilities	$ 14	$ 14