Fair Value of Financial Instruments - Fair Value Measurements of Investments (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity and other investments	$ 159,301	$ 154,511
Total investments at fair value	7,506,497	7,244,282
Interest rate swaps	31,491	(25,214)
Total	7,537,988	7,219,068
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total investments at fair value	266,130	144,707
Interest rate swaps	31,491	(25,214)
Total	297,621	119,493
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Equity and other investments	159,301	154,511
Total investments at fair value	7,240,367	7,099,575
Total	7,240,367	7,099,575
First-lien Debt Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt investments	7,103,934	6,871,809
First-lien Debt Investments | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt investments	265,225	143,398
First-lien Debt Investments | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt investments	6,838,709	6,728,411
Second-lien Debt Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt investments	33,170	94,778
Second-lien Debt Investments | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt investments	905	1,309
Second-lien Debt Investments | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt investments	32,265	93,469
Mezzanine Debt Investments
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt investments	210,092	123,184
Mezzanine Debt Investments | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt investments	$ 210,092	$ 123,184