Investments at Fair Value - Summary of Investments at Fair Value (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	[1]	$ 3,251,012	$ 2,774,726
Fair Value		3,283,065	2,787,925
Net Unrealized Gain (Loss)		32,053	13,199
First-lien Debt Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	[1]	2,956,079	2,529,317
Fair Value		2,996,177	2,517,894
Net Unrealized Gain (Loss)		40,098	(11,423)
Second-lien Debt Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	[1]	51,423	42,743
Fair Value		35,975	40,762
Net Unrealized Gain (Loss)		(15,448)	(1,981)
Mezzanine Debt Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	[1]	38,022	7,497
Fair Value		39,471	10,158
Net Unrealized Gain (Loss)		1,449	2,661
Equity and Other Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	[1]	152,623	142,103
Fair Value		155,600	167,685
Net Unrealized Gain (Loss)		2,977	25,582
Structured Credit Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	[1]	52,865	53,066
Fair Value		55,842	51,426
Net Unrealized Gain (Loss)		$ 2,977	$ (1,640)

[1] The amortized cost represents the original cost adjusted for the amortization of discounts or premiums, as applicable, on debt investments using the effective interest method.