COMMITMENTS, CONTINGENCIES AND GUARANTEES, Commitments and Contingencies (Details) $ in Millions	3 Months Ended
	Dec. 31, 2021 USD ($)
Independent venture capital or private equity investment commitment
Commitments [Line Items]
Amount of commitment	$ 25
Commitment to lend to RJTCF
Commitments [Line Items]
Amount of commitment	$ 97
Number of days that investments in project partnerships typically sold	90 days
Forward GNMA MBS purchase commitments
Commitments [Line Items]
Amount of commitment	$ 140
Expected time of purchase (in days)	90 days