INCOME TAXES - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended													12 Months Ended
	Mar. 31, 2025	Dec. 31, 2024	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Tax Contingency [Line Items]
Dividends	$ 33,700
Dividends declared (in usd per share)	$ 0.64
Dividends cash paid (in usd per share)		$ 0.63	$ 0.64	$ 0.63	$ 0.63	$ 0.63	$ 0.62	$ 0.59	$ 0.58	$ 0.57	$ 0.50	$ 0.63	$ 0.48	$ 2.53	$ 2.42	$ 2.18
Total distributions (in percent)														92.89%	94.17%
Undistributed ordinary income - tax basis	$ 41,594				$ 28,845				$ 16,070
Cumulative undistributed taxable income (in usd per share)	$ 0.79
Cost of investments	$ 1,776,100				1,471,100
Gross unrealized appreciation	117,400				96,300
Gross unrealized depreciation	108,200				96,400
Net unrealized appreciation (depreciation)	9,200				100
Total net deferred tax (liabilities) assets	(16,780)				$ (11,997)
RIC
Income Tax Contingency [Line Items]
Cost of investments	1,718,800
Gross unrealized appreciation	15,300
Gross unrealized depreciation	95,600
Net unrealized appreciation (depreciation)	(80,300)
Taxable Subsidiary
Income Tax Contingency [Line Items]
Cost of investments	57,300
Gross unrealized appreciation	102,100
Gross unrealized depreciation	12,600
Net unrealized appreciation (depreciation)	$ 89,500
Non-U.S.
Income Tax Contingency [Line Items]
Total distributions (in percent)														92.89%
Regular Dividends
Income Tax Contingency [Line Items]
Dividends declared (in usd per share)	$ 0.58
Supplemental Dividends
Income Tax Contingency [Line Items]
Dividends declared (in usd per share)	$ 0.06