Fair Value of Investments - Schedule of Net Change in Unrealized Gains on Investments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net change in unrealized gain (loss)	$ (3,566)	$ 84,196	$ 89,903	$ (156,428)
First-lien senior secured debt investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net change in unrealized gain (loss)	8,740	28,663	14,469	(97,931)
Second-lien senior secured debt investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net change in unrealized gain (loss)	(4,910)	(7,756)	(100)	(80,309)
Unsecured debt investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net change in unrealized gain (loss)	(7,587)	(14,345)	3,903	(39,287)
Preferred equity investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net change in unrealized gain (loss)	(921)	4,295	2,617	(14,675)
Common equity investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Net change in unrealized gain (loss)	$ 1,112	$ 73,339	$ 69,014	$ 75,774