Fair Value of Investments - Schedule of Net Change in Unrealized Gains on Investments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net change in unrealized gain (loss)	$ 15,390	$ (94,864)	$ 157,476
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net change in unrealized gain (loss) on investments
First-lien senior secured debt investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net change in unrealized gain (loss)	$ 12,696	(106,893)	59,528
Second-lien senior secured debt investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net change in unrealized gain (loss)	(37,381)	(68,165)	11,446
Unsecured debt investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net change in unrealized gain (loss)	14,215	(20,259)	(3,802)
Preferred equity investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net change in unrealized gain (loss)	9,854	(10,388)	4,245
Common equity investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net change in unrealized gain (loss)	$ 16,006	$ 110,841	$ 86,059