SIGNIFICANT SUBSIDIARIES - Summarized Financial Information Operation Statement (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2021
Investment Company, Nonconsolidated Subsidiary [Line Items]
Net investment income	$ 22,404	$ 19,425	$ 14,444	$ 12,438	$ 12,019	$ 11,899	$ 9,726	$ 9,043	$ 68,711	$ 42,687	$ 31,671
Net unrealized depreciation (appreciation) on investments	$ (4,600)	$ (5,390)	$ 3,649	$ (12,248)	$ 7,161	$ (2,054)	$ (691)	$ 7,051	(18,589)	11,467	28,755
I-45 SLF LLC
Investment Company, Nonconsolidated Subsidiary [Line Items]
Total revenues									16,914	12,804	13,930
Total expenses									(7,542)	(4,166)	(4,565)
Net investment income									9,372	8,638	9,365
Net unrealized depreciation (appreciation) on investments									(15,153)	(4,569)	30,467
Net realized gains (losses)									1,224	1,047	(15,313)
Net (decrease) increase in members’ equity resulting from operations									$ (4,557)	$ 5,116	$ 24,519