INCOME TAXES - RIC Accumulated Earnings (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2023
Income Tax Disclosure [Abstract]
Undistributed ordinary income - tax basis	$ 41,594	$ 28,845	$ 16,070
Undistributed net realized (loss) gain	(130,951)	(60,056)	(30,201)
Unrealized (depreciation) appreciation on investments	(80,308)	(68,529)	(61,710)
Other temporary differences	(4,201)	(9,584)	(13,639)
Components of distributable earnings at year-end	$ (173,866)	$ (109,324)	$ (89,480)