Fair Value of Financial Instruments - Net Change in Unrealized Gains or Losses on Investments for Which Level 3 Inputs were Used in Determining Fair Value (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Net Unrealized Gain (Loss)	$ 183,785		$ 164,288
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Net Unrealized Gain (Loss)	38,637	$ 18,893
Level 3 | First-lien Debt Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Net Unrealized Gain (Loss)	23,712	13,833
Level 3 | Second-lien Debt Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Net Unrealized Gain (Loss)	7,086	(227)
Level 3 | Mezzanine Debt Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Net Unrealized Gain (Loss)	1,564	1,804
Level 3 | Equity and Other Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Net Unrealized Gain (Loss)	$ 6,275	$ 3,483