Consolidated Statements of Operations - USD ($) $ in Thousands		12 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Investment income:
Total investment income		$ 104,966	$ 81,588	$ 100,225
Expenses:
Base management fee (See Note 3)		19,827	17,335	18,636
Performance-based incentive fee (See Note 3)		2,657	575	4,580
Interest and expenses on debt (See Note 11)		28,760	22,507	32,168
Administrative services expenses (See Note 3)		1,000	1,771	2,075
Other general and administrative expenses		2,892	2,324	2,574
Expenses before Management Fees waiver, provision for taxes and financing costs		55,136	44,512	60,033
Management Fees waiver (See Note 3)				(1,922)
Provision for taxes		800	600	1,200
PSLF transaction costs (Note 4)				2,184
Credit facility amendment and debt issuance costs (See Notes 5 and 11)		5,087
Net expenses		61,023	45,112	61,495
Net investment income		43,943	36,476	38,730
Net realized gain (loss) on:
Non-controlled, non-affiliated investments		(31,382)	49,729	(11,577)
Non-controlled and controlled, affiliated investments		75,243	(19,708)
Debt extinguishment realized loss		(2,922)
Provision for taxes on realized gain on investments		(6,183)
Deconsolidation loss (Note 4)				(9,250)
Net realized (loss) gain on investments		34,756	30,021	(20,827)
Net change in change in unrealized (depreciation) appreciation on:
Non-controlled, non-affiliated investments		(182,863)	50,130	7,687
Non-controlled and controlled, affiliated investments		72,819	67,808	(53,864)
Provision for taxes on unrealized appreciation on investments		(896)
Debt (See Notes 5 and 11)		7,501	(17,818)	12,304
Net change in unrealized (depreciation) appreciation on investments and debt		(103,439)	100,120	(33,873)
Net realized and change in unrealized gain (loss) from investments and debt		(68,683)	130,141	(54,700)
Net (decrease) increase in net assets resulting from operations		$ (24,740)	$ 166,617	$ (15,970)
Net (decrease) increase in net assets resulting from operations per common share (See Note 7)		$ (0.37)	$ 2.49	$ (0.24)
Net investment income per common share	[1]	$ 0.66	$ 0.54	$ 0.58
Non-controlled, Non-affiliated Investments
Investment income:
Interest		$ 66,995	$ 46,018	$ 77,453
Payment-in-kind		4,505	8,567	7,233
Other income		8,461	4,137	4,822
Non-controlled, Affiliated Investments
Investment income:
Interest		1,361	457
Controlled, Affiliated Investments
Investment income:
Interest		10,586	9,825	3,388
Payment-in-kind		3,983	6,223	$ 7,329
Dividend income		$ 9,075	$ 6,361

[1] Based on the weighted average shares outstanding for the respective periods.