Investments at Fair Value - Summary of Investments at Fair Value (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 5,774,926	$ 3,037,826
Fair Value	5,926,828	3,099,151
Net Unrealized Gain (Loss)	151,902	61,325
First-lien Debt Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	5,480,669	2,792,928
Fair Value	5,611,439	2,850,885
Net Unrealized Gain (Loss)	130,770	57,957
Second-lien Debt Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	88,822	77,895
Fair Value	94,874	79,091
Net Unrealized Gain (Loss)	6,052	1,196
Mezzanine Debt Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	114,525	104,352
Fair Value	119,293	106,524
Net Unrealized Gain (Loss)	4,768	2,172
Equity and Other Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	90,910	62,651
Fair Value	101,222	$ 62,651
Net Unrealized Gain (Loss)	$ 10,312