Fair Value Measurement - Summary of Ranges of Significant Unobservable Inputs Used to Value Level 3 Assets (Details) $ in Thousands		Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value		$ 3,440,114	$ 3,414,329
1st Lien/Senior Secured Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value		3,162,664	3,107,469
1st Lien/Last-Out Unitranche
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value		158,514	144,743
2nd Lien/Senior Secured Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value		33,636	66,562
Unsecured Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value		20,550	27,314
Preferred Stock
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value		38,002	37,296
Common Stock
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value		26,501	30,701
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value		3,377,068	3,343,635
Level 3 | 1st Lien/Senior Secured Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value		3,099,816	3,036,965
Level 3 | 1st Lien/Last-Out Unitranche
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value		158,514	144,743
Level 3 | 2nd Lien/Senior Secured Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value		33,636	66,562
Level 3 | Unsecured Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value		20,550	27,314
Level 3 | Preferred Stock
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value		38,002	37,296
Level 3 | Common Stock
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value		26,303	30,511
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation Technique, Discounted Cash Flow | Measurement Input, Discount Rate | 1st Lien/Senior Secured Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value	[1],[2]	$ 2,905,289	$ 2,744,907
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation Technique, Discounted Cash Flow | Measurement Input, Discount Rate | 1st Lien/Senior Secured Debt | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt Investments, Range of Significant Unobservable Inputs	[3]	0.087	0.088
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation Technique, Discounted Cash Flow | Measurement Input, Discount Rate | 1st Lien/Senior Secured Debt | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt Investments, Range of Significant Unobservable Inputs	[3]	0.524	0.318
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation Technique, Discounted Cash Flow | Measurement Input, Discount Rate | 1st Lien/Senior Secured Debt | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt Investments, Range of Significant Unobservable Inputs	[4]	0.124	0.116
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation Technique, Discounted Cash Flow | Measurement Input, Discount Rate | 1st Lien/Last-Out Unitranche
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value	[1],[2]	$ 149,087	$ 125,245
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation Technique, Discounted Cash Flow | Measurement Input, Discount Rate | 1st Lien/Last-Out Unitranche | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt Investments, Range of Significant Unobservable Inputs	[3]	0.087	0.089
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation Technique, Discounted Cash Flow | Measurement Input, Discount Rate | 1st Lien/Last-Out Unitranche | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt Investments, Range of Significant Unobservable Inputs	[3]	0.129	0.126
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation Technique, Discounted Cash Flow | Measurement Input, Discount Rate | 1st Lien/Last-Out Unitranche | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt Investments, Range of Significant Unobservable Inputs	[4]	0.122	0.123
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation Technique, Discounted Cash Flow | Measurement Input, Discount Rate | 2nd Lien/Senior Secured Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value	[1],[2]	$ 27,538	$ 50,052
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation Technique, Discounted Cash Flow | Measurement Input, Discount Rate | 2nd Lien/Senior Secured Debt | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt Investments, Range of Significant Unobservable Inputs	[3]	0.175	0.124
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation Technique, Discounted Cash Flow | Measurement Input, Discount Rate | 2nd Lien/Senior Secured Debt | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt Investments, Range of Significant Unobservable Inputs	[3]	0.205	0.169
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation Technique, Discounted Cash Flow | Measurement Input, Discount Rate | 2nd Lien/Senior Secured Debt | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt Investments, Range of Significant Unobservable Inputs	[4]	0.193	0.133
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation Technique, Discounted Cash Flow | Measurement Input, Discount Rate | Unsecured Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value	[1],[2]	$ 19,123	$ 17,905
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation Technique, Discounted Cash Flow | Measurement Input, Discount Rate | Unsecured Debt | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt Investments, Range of Significant Unobservable Inputs	[3]	0.173	0.158
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation Technique, Discounted Cash Flow | Measurement Input, Discount Rate | Unsecured Debt | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt Investments, Range of Significant Unobservable Inputs	[3]	0.208	0.203
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation Technique, Discounted Cash Flow | Measurement Input, Discount Rate | Unsecured Debt | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt Investments, Range of Significant Unobservable Inputs	[4]	0.191	0.187
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation Technique, Collateral Analysis | Measurement Input, Recovery Rate | 1st Lien/Senior Secured Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value	[1],[2]	$ 901	$ 1,073
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation Technique, Collateral Analysis | Measurement Input, Recovery Rate | 1st Lien/Senior Secured Debt | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt Investments, Range of Significant Unobservable Inputs	[4]	0.23	0.274
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/EBITDA | 1st Lien/Senior Secured Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value	[1],[2]		$ 40,591
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/EBITDA | 1st Lien/Senior Secured Debt | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt Investments, Range of Significant Unobservable Inputs	[4]		10
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/EBITDA | 2nd Lien/Senior Secured Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value	[1],[2]	$ 6,098	$ 1,701
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/EBITDA | 2nd Lien/Senior Secured Debt | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt Investments, Range of Significant Unobservable Inputs	[3]	8.6
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/EBITDA | 2nd Lien/Senior Secured Debt | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt Investments, Range of Significant Unobservable Inputs	[3]	9.5
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/EBITDA | 2nd Lien/Senior Secured Debt | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt Investments, Range of Significant Unobservable Inputs	[4]	9.2	8.3
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/EBITDA | Unsecured Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value	[1],[2]	$ 276	$ 255
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/EBITDA | Unsecured Debt | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt Investments, Range of Significant Unobservable Inputs	[4]	7.5	8.9
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/Revenue | 1st Lien/Senior Secured Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value	[1],[2]	$ 52,252	$ 58,157
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/Revenue | 1st Lien/Senior Secured Debt | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt Investments, Range of Significant Unobservable Inputs	[3]	0.4	0.4
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/Revenue | 1st Lien/Senior Secured Debt | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt Investments, Range of Significant Unobservable Inputs	[3]	2.8	2.7
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/Revenue | 1st Lien/Senior Secured Debt | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt Investments, Range of Significant Unobservable Inputs	[4]	2	1.8
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/Revenue | 2nd Lien/Senior Secured Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value	[1],[2]		$ 14,809
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/Revenue | 2nd Lien/Senior Secured Debt | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt Investments, Range of Significant Unobservable Inputs	[4]		0.3
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/Revenue | Unsecured Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value	[1],[2]	$ 1,151	$ 9,154
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/Revenue | Unsecured Debt | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt Investments, Range of Significant Unobservable Inputs	[4]	0.3	0.4
Equity | Level 3 | Valuation Technique, Discounted Cash Flow | Measurement Input, Discount Rate | Common Stock | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity, Fair Value	[1],[2]	$ 5,396	$ 9,518
Equity, Range of Significant Unobservable Inputs	[3]		0.168
Equity | Level 3 | Valuation Technique, Discounted Cash Flow | Measurement Input, Discount Rate | Common Stock | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity, Range of Significant Unobservable Inputs	[3]		0.297
Equity | Level 3 | Valuation Technique, Discounted Cash Flow | Measurement Input, Discount Rate | Common Stock | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity, Range of Significant Unobservable Inputs	[4]	0.296	0.249
Equity | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/EBITDA | Preferred Stock | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity, Fair Value	[1],[2]	$ 13,307	$ 12,846
Equity, Range of Significant Unobservable Inputs	[3]	10	13.7
Equity | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/EBITDA | Preferred Stock | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity, Range of Significant Unobservable Inputs	[3]	31.2	31.2
Equity | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/EBITDA | Preferred Stock | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity, Range of Significant Unobservable Inputs	[4]	31	31.1
Equity | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/EBITDA | Common Stock | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity, Fair Value	[1],[2]	$ 16,877	$ 16,950
Equity, Range of Significant Unobservable Inputs	[3]	3.5	3.8
Equity | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/EBITDA | Common Stock | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity, Range of Significant Unobservable Inputs	[3]	17.5	17.5
Equity | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/EBITDA | Common Stock | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity, Range of Significant Unobservable Inputs	[4]	9	9.2
Equity | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/Revenue
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrants, Fair Value	[1],[2]	$ 247	$ 244
Equity | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/Revenue | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrants, Range of Significant Unobservable Inputs	[4]	4	4
Equity | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/Revenue | Preferred Stock | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity, Fair Value	[1],[2]	$ 24,695	$ 24,450
Equity, Range of Significant Unobservable Inputs	[3]	4	4
Equity | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/Revenue | Preferred Stock | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity, Range of Significant Unobservable Inputs	[3]	5.7	4.1
Equity | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/Revenue | Preferred Stock | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity, Range of Significant Unobservable Inputs	[4]	4.6	4
Equity | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/Revenue | Common Stock | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity, Fair Value	[1],[2]	$ 4,030	$ 4,043
Equity | Level 3 | Valuation, Comparable Multiples | Measurement Input, EV/Revenue | Common Stock | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity, Range of Significant Unobservable Inputs	[4]	14.7	14.8

[1] As of December 31, 2023, included within the fair value of Level 3 assets of $3,343,635 is an amount of $211,735 for which the Investment Adviser did not develop the unobservable inputs (examples include single source broker quotations, third party pricing, and prior transactions). The income approach was used in the determination of fair value for $2,938,109 or 89.7% of Level 3 bank loans, corporate debt, and other debt obligations.

[2] As of March 31, 2024, included within the fair value of Level 3 assets of $3,377,068 is an amount of $150,801 for which the Investment Adviser did not develop the unobservable inputs (examples include single source broker quotations, third party pricing, and prior transactions). The income approach was used in the determination of fair value for $3,101,037 or 93.6% of Level 3 bank loans, corporate debt, and other debt obligations.

[3] The range for an asset category consisting of a single investment, if any, is not meaningful and therefore has been excluded.

[4] Weighted average for an asset category consisting of multiple investments is calculated by weighting the significant unobservable input by the relative fair value of the investment. Weighted average for an asset category consisting of a single investment represents the significant unobservable input used in the fair value of the investment.