Consolidated Statements of Operations (unaudited) - USD ($) $ in Thousands		12 Months Ended
		Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Investment income
Payment-in-kind interest income		$ 52,323	$ 49,715	$ 40,590
Total investment income		870,777	724,677	603,090
Expenses
Interest and other debt financing expenses		290,618	212,396	150,610
Base management fee		87,891	62,514	70,802
Incentive fee		73,282	77,163	74,066
Professional fees		8,011	5,496	5,041
Administrative service fee		12,251	9,320	8,300
General and administrative expenses		1,920	1,481	1,501
Total expenses		473,973	368,370	310,320
Net expenses		473,973	341,046	310,320
Net investment income - before tax		396,804	383,631	292,770
Excise and income tax		(475)	1,195	3,682
Net investment income - after tax		397,279	382,436	289,088
Net realized gain (loss) from:
Company investments		(72,214)	(81,577)	(46,496)
Foreign currency transactions		(4,334)	(1,969)	(328)
Forward currency contracts		4,168	3,646	2,711
Net realized gain (loss) on investment transactions		(72,380)	(79,900)	(44,113)
Net change in unrealized appreciation (depreciation) from:
Company investments		50,589	(32,048)	14,267
Translation of assets and liabilities in foreign currencies		9,185	21,688	16,680
Net change in unrealized appreciation (depreciation) on investment transactions		51,232	(29,371)	13,555
Net gain (loss) on investment transactions		(21,148)	(109,271)	(30,558)
Net realized gain (loss) on extinguishment of debt		(48)	0	0
(Provision) benefit for taxes on realized gain on investments		0	0	(207)
(Provision) benefit for taxes on unrealized appreciation on investments		563	620	308
Net increase (decrease) in net assets resulting from operations		$ 376,646	$ 273,785	$ 258,631
Per Common Share Data
Basic earnings per common share (Note 10) (in dollars per share)		$ 1.42	$ 1.36	$ 1.52
Diluted earnings per common share (Note 10) (in dollars per share)		1.42	1.36	1.52
Dividends and distributions declared per common share (in dollars per share)		$ 1.65	$ 1.89	$ 1.40
Basic weighted average common shares outstanding (Note 10) (in shares)		265,999,341	201,260,961	170,324,784
Diluted weighted average common shares outstanding (Note 10) (in shares)		265,999,341	201,260,961	170,324,784
Foreign exchange
Net realized gain (loss) from:
Forward currency contracts		$ 4,168	$ 3,646	$ 2,711
Net change in unrealized appreciation (depreciation) from:
Forward currency contracts		(8,542)	(19,011)	(17,392)
Non-controlled/non-affiliate company investments
Investment income
Interest income		772,134	645,747	542,780
Payment-in-kind interest income		49,253	44,934	36,662
Dividend income		32,647	21,955	16,241
Fee income		4,775	2,154	2,124
Total investment income		858,809	714,790	597,807
Net realized gain (loss) from:
Company investments		(72,214)	(49,491)	(45,889)
Net change in unrealized appreciation (depreciation) from:
Company investments		54,466	(47,054)	33,464
Non-controlled affiliate company investments
Investment income
Interest income		8,768	4,982	1,356
Payment-in-kind interest income		2,579	4,355	3,544
Fee income		111	111	76
Total investment income		11,458	9,448	4,976
Net realized gain (loss) from:
Company investments		0	(20,460)	320
Net change in unrealized appreciation (depreciation) from:
Company investments		(3,044)	4,600	(18,578)
Controlled affiliate company investments
Investment income
Payment-in-kind interest income		491	426	384
Fee income		19	13	17
Total investment income		510	439	307
Interest income	[1]	0	0	(94)
Net realized gain (loss) from:
Company investments		0	(11,626)	(927)
Net change in unrealized appreciation (depreciation) from:
Company investments		$ (833)	$ 10,406	$ (619)

[1] Negative interest income amounts are due to amortization of the GCIC acquisition purchase premium. Refer to Note 2 for additional details on the GCIC acquisition purchase premium.