COMMITMENTS, CONTINGENCIES AND GUARANTEES, Commitments Narrative (Details) $ in Millions	12 Months Ended
	Sep. 30, 2024 USD ($) commitment
Underwriting commitment
Commitments [Line Items]
Number of open underwriting commitments | commitment	3
Unfunded lending commitments
Commitments [Line Items]
Amount of commitment	$ 19
Various investment commitment
Commitments [Line Items]
Amount of commitment	76
Commitment to lend to RJTCF
Commitments [Line Items]
Amount of commitment	$ 46
Number of days that investments in project partnerships are typically sold (in days)	90 days