Share Data and Distributions - Schedule of Changes in Net Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Investment Company, Net Assets [Roll Forward]
Beginning of period (in shares)	64,896,000
Net assets at beginning of period	$ 1,529,205	$ 366,727
Issuance of Common Shares in public offering	468,787	129,708
Issuance of Common shares under dividend reinvestment plan	11,647	$ 1,832
Shares repurchased, net of early repurchase deduction (in shares)		0
Shares repurchased, net of early repurchase deduction	(10,526)
Net investment income	35,803	$ 10,097
Net unrealized appreciation (depreciation)	16,919	(2,842)
Net realized gains (losses)	453	(660)
Provision for income tax (expense) benefit	(241)	(51)
Distributions to shareholders	$ (46,876)	(11,356)
End of period (in shares)	84,898,000
Net assets at end of period	$ 2,005,171	$ 493,455
Common Shares
Investment Company, Net Assets [Roll Forward]
Beginning of period (in shares)	64,896	15,628
Net assets at beginning of period	$ 649	$ 156
Issuance of Common Shares in public offering (in shares)	19,952	5,536
Issuance of Common Shares in public offering	$ 199	$ 55
Issuance of Common Shares under dividend reinvestment plan (in shares)	496	78
Issuance of Common shares under dividend reinvestment plan	$ 5	$ 1
Shares repurchased, net of early repurchase deduction (in shares)	(446)
Shares repurchased, net of early repurchase deduction	$ (4)
End of period (in shares)	84,898	21,242
Net assets at end of period	$ 849	$ 212
Additional Paid-in-Capital
Investment Company, Net Assets [Roll Forward]
Net assets at beginning of period	1,536,305	380,646
Issuance of Common Shares in public offering	468,588	129,653
Issuance of Common shares under dividend reinvestment plan	11,642	1,831
Shares repurchased, net of early repurchase deduction	(10,522)
Net assets at end of period	2,006,013	512,130
Accumulated Distributable Earnings (Loss)
Investment Company, Net Assets [Roll Forward]
Net assets at beginning of period	(7,749)	(14,075)
Net investment income	35,803	10,097
Net unrealized appreciation (depreciation)	16,919	(2,842)
Net realized gains (losses)	453	(660)
Provision for income tax (expense) benefit	(241)	(51)
Distributions to shareholders	(46,876)	(11,356)
Net assets at end of period	$ (1,691)	$ (18,887)