VARIABLE INTEREST ENTITIES, Not the Primary Beneficiary - Aggregate Assets, Liabilities Exposure to Loss (Details) - USD ($) $ in Millions	Jun. 30, 2022	Sep. 30, 2021
Variable Interest Entity [Line Items]
Aggregate assets	$ 86,111	$ 61,891
Aggregate liabilities	76,619	53,588
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Aggregate assets	9,595	14,869
Aggregate liabilities	2,971	2,482
Our risk of loss	180	163
Private Equity Interests | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Aggregate assets	2,108	7,318
Aggregate liabilities	418	47
Our risk of loss	100	82
LIHTC funds | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Aggregate assets	7,315	7,032
Aggregate liabilities	2,431	2,280
Our risk of loss	71	71
Other | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Aggregate assets	172	519
Aggregate liabilities	122	155
Our risk of loss	$ 9	$ 10