COMMITMENTS, CONTINGENCIES AND GUARANTEES, Commitments Narrative (Details) $ in Millions	12 Months Ended
	Sep. 30, 2023 USD ($) agreement
Underwriting commitment
Commitments [Line Items]
Number of open underwriting commitments | agreement	1
Various Investment Commitment
Commitments [Line Items]
Amount of commitment	$ 69
Commitment to lend to RJTCF
Commitments [Line Items]
Amount of commitment	$ 93
Number of days that investments in project partnerships are typically sold (in days)	90 days