Fair Value Measurement - Summary of Ranges of Significant Unobservable Inputs Used to Value Level 3 Assets (Details) $ in Thousands	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value	$ 3,506,216	$ 3,478,443
1st Lien/Senior Secured Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value	3,129,552	2,945,368
1st Lien/Last-Out Unitranche
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value	116,230	162,532
2nd Lien/Senior Secured Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value	174,326	283,521
Unsecured Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value	7,630	1,733
Preferred Stock
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value	42,377	52,655
Common Stock
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value	35,490	30,784
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value	3,341,847	3,270,660
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	3,050,929	2,843,010
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	116,230	162,532
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	89,573	178,780
Level 3 | Unsecured Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value	7,630	1,733
Level 3 | Preferred Stock
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value	42,377	52,655
Level 3 | Common Stock
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value	34,497	30,100
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	$ 2,920,976	$ 2,271,598
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	0.074	0.071
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	0.352	0.225
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	0.114	0.091
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	$ 116,230	$ 162,532
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	0.109	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	0.150	0.101
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	0.141	0.094
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	$ 87,872	$ 177,079
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	0.127	0.097
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	0.177	0.154
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	0.139	0.112
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	$ 7,630	$ 1,333
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	0.135
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	0.173
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	0.165	0.148
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	$ 1,283	$ 1,328
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	0.329	0.339
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation Technique, Collateral Analysis | Measurement Input, Recovery Rate | Unsecured Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value		$ 400
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation Technique, Collateral Analysis | Measurement Input, Recovery 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		0.316
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	$ 4,486
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	12.0
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	$ 1,701	$ 1,701
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	9.9	9.3
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation, Comparable Multiples | Measurement Input, Revenue Multiple | 1st Lien/Senior Secured Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Debt investments, Fair Value	$ 806
Bank Loans, Corporate Debt and Other Debt Obligations | Level 3 | Valuation, Comparable Multiples | Measurement Input, Revenue Multiple | 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	2.3
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	$ 10,322	$ 10,887
Equity, Range of Significant Unobservable Inputs	0.163	0.146
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	0.300	0.311
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	0.246	0.241
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	$ 14,297	$ 2,425
Equity, Range of Significant Unobservable Inputs	14.4	10.5
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	29.7	21.4
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	28.2	21.2
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	$ 20,391	$ 12,871
Equity, Range of Significant Unobservable Inputs	4.5	4.4
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	18.3	19.2
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	9.7	10.3
Equity | Level 3 | Valuation, Comparable Multiples | Measurement Input, Revenue Multiple
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrants, Fair Value	$ 611	$ 1,850
Equity | Level 3 | Valuation, Comparable Multiples | Measurement Input, Revenue Multiple | Weighted Average
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Warrants, Range of Significant Unobservable Inputs		8.2
Equity | Level 3 | Valuation, Comparable Multiples | Measurement Input, Revenue Multiple | Preferred Stock | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity, Fair Value	$ 28,081	$ 18,121
Equity, Range of Significant Unobservable Inputs	0.8	1.5
Equity | Level 3 | Valuation, Comparable Multiples | Measurement Input, Revenue Multiple | Preferred Stock | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity, Range of Significant Unobservable Inputs	7.3	5.7
Equity | Level 3 | Valuation, Comparable Multiples | Measurement Input, Revenue Multiple | 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	4.1	2.0
Warrants, Range of Significant Unobservable Inputs	4.0
Equity | Level 3 | Valuation, Comparable Multiples | Measurement Input, Revenue Multiple | Common Stock | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity, Fair Value	$ 3,784	$ 4,002
Equity, Range of Significant Unobservable Inputs	1.8	0.7
Equity | Level 3 | Valuation, Comparable Multiples | Measurement Input, Revenue Multiple | Common Stock | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity, Range of Significant Unobservable Inputs	15.2	18.9
Equity | Level 3 | Valuation, Comparable Multiples | Measurement Input, Revenue Multiple | 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	12.6	14.9