Investments at Fair Value - Summary of Investments at Fair Value (Details) - USD ($) $ in Thousands		6 Months Ended	12 Months Ended
		Jun. 30, 2025	Dec. 31, 2024
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	[1]	$ 7,203,329	$ 7,079,994
Fair Value		7,506,497	7,244,282
Net Unrealized Gain (Loss)		303,168	164,288
First-lien Debt Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	[1]	6,828,604	6,732,065
Fair Value		7,103,934	6,871,809
Net Unrealized Gain (Loss)		275,330	139,744
Second-lien Debt Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	[1]	32,361	89,461
Fair Value		33,170	94,778
Net Unrealized Gain (Loss)		809	5,317
Mezzanine Debt Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	[1]	202,849	118,441
Fair Value		210,092	123,184
Net Unrealized Gain (Loss)		7,243	4,743
Equity and Other Investments
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	[1]	139,515	140,027
Fair Value		159,301	154,511
Net Unrealized Gain (Loss)		$ 19,786	$ 14,484

[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.