INCOME TAXES - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended					9 Months Ended
	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2021
Income Tax Contingency [Line Items]
Dividends	$ 19,300	$ 14,300	$ 16,600	$ 11,800
Dividends cash paid (in usd per share)			$ 0.63	$ 0.48
Dividends declared (in usd per share)	$ 0.57	$ 0.50
Cost of investments	$ 1,150,600			$ 852,400		$ 1,150,600
Gross unrealized appreciation	66,900			67,800		66,900
Gross unrealized depreciation	(66,700)			(61,700)		(66,700)
Net unrealized appreciation (depreciation)	200			6,100		200
Deferred tax liability	11,427			$ 5,747		11,427
Income tax provision	(746)				$ (62)	(20)	$ 648
Excise tax	200				100	468	191
RIC
Income Tax Contingency [Line Items]
Cost of investments	1,116,800					1,116,800
Gross unrealized appreciation	9,700					9,700
Gross unrealized depreciation	(64,300)					(64,300)
Net unrealized appreciation (depreciation)	(54,600)					(54,600)
Taxable Subsidiary
Income Tax Contingency [Line Items]
Cost of investments	33,800					33,800
Gross unrealized appreciation	57,200					57,200
Gross unrealized depreciation	(2,400)					(2,400)
Net unrealized appreciation (depreciation)	54,800					54,800
Income tax provision	$ (900)				$ 200	$ (488)	$ 457
Regular Dividends
Income Tax Contingency [Line Items]
Dividends cash paid (in usd per share)			0.48
Dividends declared (in usd per share)	$ 0.52
Special Dividend
Income Tax Contingency [Line Items]
Dividends cash paid (in usd per share)			$ 0.15
Supplemental dividend
Income Tax Contingency [Line Items]
Dividends declared (in usd per share)	$ 0.05