CONSOLIDATED STATEMENTS OF CHANGES IN NET ASSETS - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Mar. 31, 2025	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2023
Investment Company, Net Assets [Roll Forward]
Beginning balance (in shares)		45,050,759		36,076,000	45,050,759	36,076,000	24,959,000
Beginning balance		$ 755,676		$ 590,408	$ 755,676	$ 590,408	$ 420,867
Issuance of common stock					178,472	181,387	202,781
Cancellation of treasury shares						0
Share-based compensation					6,963	4,518	3,705
Issuance of common stock under restricted stock plan, net of forfeitures					0	0	0
Common stock withheld for payroll taxes upon vesting of restricted stock					(2,708)	(1,063)	(1,021)
Dividends to shareholders					(125,267)	(102,925)	(71,102)
Change in restoration plan liability					(51)	(38)	2,085
Reclassification for certain permanent book-to-tax differences					0	0	0
Net investment income	$ 27,842	28,859	$ 29,396	24,556	118,182	110,005	68,711
Net realized loss on investments and extinguishment of debt					(50,057)	(40,256)	(17,029)
Net unrealized (depreciation) appreciation on investments	$ 16,997	$ (15,535)	$ 3,734	$ 12,038	$ 2,423	$ 13,640	$ (18,589)
Ending balance (in shares)	52,912,796		45,050,759		52,912,796	45,050,759	36,076,000
Ending balance	$ 883,633		$ 755,676		$ 883,633	$ 755,676	$ 590,408
Common Stock
Investment Company, Net Assets [Roll Forward]
Beginning balance (in shares)		45,050,759		36,076,425	45,050,759	36,076,425	24,958,520
Beginning balance		$ 11,263		$ 9,604	$ 11,263	$ 9,604	$ 6,825
Issuance of common stock (in shares)					7,694,740	8,733,315	10,969,898
Issuance of common stock					$ 1,924	$ 2,183	$ 2,742
Cancellation of treasury shares						$ (585)
Issuance of common stock under restricted stock plan, net of forfeitures (in shares)					274,575	293,816	197,597
Issuance of common stock under restricted stock plan, net of forfeitures					$ 68	$ 74	$ 49
Common stock withheld for payroll taxes upon vesting of restricted stock (in shares)					(107,278)	(52,797)	(49,590)
Common stock withheld for payroll taxes upon vesting of restricted stock					$ (27)	$ (13)	$ (12)
Ending balance (in shares)	52,912,796		45,050,759		52,912,796	45,050,759	36,076,425
Ending balance	$ 13,228		$ 11,263		$ 13,228	$ 11,263	$ 9,604
Treasury Stock
Investment Company, Net Assets [Roll Forward]
Beginning balance		$ 0		$ (23,937)	$ 0	$ (23,937)	$ (23,937)
Beginning balance (in shares)		0		2,339,512	0	2,339,512	2,339,512
Cancellation of treasury shares						$ 23,937
Cancellation of treasury stock (in shares)						(2,339,512)
Ending balance	$ 0		$ 0		$ 0	$ 0	$ (23,937)
Ending balance (in shares)	0		0		0	0	2,339,512
Additional Paid-In Capital
Investment Company, Net Assets [Roll Forward]
Beginning balance		$ 796,945		$ 646,586	$ 796,945	$ 646,586	$ 448,235
Issuance of common stock					176,548	179,204	200,039
Cancellation of treasury shares						(23,352)
Share-based compensation					6,963	4,518	3,705
Issuance of common stock under restricted stock plan, net of forfeitures					(68)	(74)	(49)
Common stock withheld for payroll taxes upon vesting of restricted stock					(2,681)	(1,050)	(1,009)
Change in restoration plan liability					(51)	(38)	2,085
Reclassification for certain permanent book-to-tax differences					(18,533)	(8,849)	(6,420)
Ending balance	$ 959,123		$ 796,945		959,123	796,945	646,586
Total Distributable Earnings (Loss)
Investment Company, Net Assets [Roll Forward]
Beginning balance		$ (52,532)		$ (41,845)	(52,532)	(41,845)	(10,256)
Dividends to shareholders					(125,267)	(102,925)	(71,102)
Reclassification for certain permanent book-to-tax differences					18,533	8,849	6,420
Net investment income					118,182	110,005	68,711
Net realized loss on investments and extinguishment of debt					(50,057)	(40,256)	(17,029)
Net unrealized (depreciation) appreciation on investments					2,423	13,640	(18,589)
Ending balance	$ (88,718)		$ (52,532)		$ (88,718)	$ (52,532)	$ (41,845)