Fair Value of Financial Instruments - Changes in Fair Value of Investments for Level 3 Inputs (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of period	$ 808,800
Purchases or originations	444,762
Repayments / redemptions	(6,286)
Paid-in-kind interest	21
Net change in unrealized gains (losses)	$ 13,761
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Unrealized Gain Loss On Investments
Net amortization of discount on securities	$ 1,394
Balance, End of Period	1,262,452
First-lien Debt Investments
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of period	800,994
Purchases or originations	436,124
Repayments / redemptions	(6,286)
Paid-in-kind interest	21
Net change in unrealized gains (losses)	13,761
Net amortization of discount on securities	1,394
Balance, End of Period	1,246,008
Equity and Other Investments
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance, beginning of period	7,806
Purchases or originations	8,638
Balance, End of Period	$ 16,444