INVESTMENT SECURITIES - Schedule of reconciliation of the beginning and ending balance for investments that use Level 3 inputs (Details) - Investments - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2025	Sep. 30, 2024
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Investments beginning	$ 18,320	$ 20,442
Reclassification to Level 3	1,041
Sale of investments that use Level 3 inputs	0
Purchase of investments that use Level 3 inputs	2,018
Revaluation of investments that use Level 3 inputs	(807)	$ (2,122)
Investments ending	$ 20,572