Investments at Fair Value - Summary of Investments at Fair Value (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 2,007,948	$ 809,029
Fair Value	2,048,389	808,801
Net Unrealized Gain (Loss)	40,441	(228)
First-lien Debt Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	1,877,359	801,223
Fair Value	1,916,510	800,995
Net Unrealized Gain (Loss)	39,151	(228)
Mezzanine Debt Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	100,330
Fair Value	101,620
Net Unrealized Gain (Loss)	1,290
Equity and Other Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	30,259	7,806
Fair Value	$ 30,259	$ 7,806