INVESTMENTS - Receivables from Portfolio Companies Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Investments, Debt and Equity Securities [Abstract]
Uncollectible receivables allowance, minimum required day for uncollectible adjustment	90 days
Gross receivables from portfolio companies	$ 2,400	$ 1,700
Allowance for uncollectible receivables	$ 52	$ 75