Fair Value of Financial Instruments - Fair Value Measurements of Investments (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity and other investments	$ 161,019	$ 155,600
Structured credit investments	6,124	55,842
Total investments at fair value	3,317,069	3,283,065
Interest rate swaps	(39,235)	(31,840)
Total	3,277,834	3,251,225
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity and other investments	3,875	5,180
Total investments at fair value	3,875	5,180
Total	3,875	5,180
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity and other investments	9,072	10,089
Structured credit investments	6,124	55,842
Total investments at fair value	19,853	68,928
Interest rate swaps	(39,235)	(31,840)
Total	(19,382)	37,088
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity and other investments	148,072	140,331
Total investments at fair value	3,293,341	3,208,957
Total	3,293,341	3,208,957
First-lien Debt Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt investments	3,078,445	2,996,177
First-lien Debt Investments | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt investments	3,451	2,391
First-lien Debt Investments | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt investments	3,074,994	2,993,786
Second-lien Debt Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt investments	27,993	35,975
Second-lien Debt Investments | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt investments	27,993	35,975
Mezzanine Debt Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt investments	43,488	39,471
Mezzanine Debt Investments | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt investments	1,206	606
Mezzanine Debt Investments | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt investments	$ 42,282	$ 38,865