v3.26.3
Fair Value of Financial Instruments - Schedule of Quantitative Information About Significant Unobservable Inputs of Level 3 Investments (Details)
Sep. 30, 2026
USD ($)
Dec. 31, 2025
USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 15,095,927,000 [1],[2] $ 16,470,893,000 [3],[4]
First-lien senior secured debt investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: 11,017,777,000 12,048,934,000
Second-lien senior secured debt investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: 699,233,000 848,575,000
Unsecured Debt    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: 389,154,000 399,962,000
Specialty finance debt investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: 178,964,000 157,297,000
Preferred    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: 275,703,000 568,977,000
Common equity investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: 713,998,000 644,304,000
Specialty finance equity investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: 1,407,540,000 1,386,739,000
Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: 14,019,965,000 15,572,144,000
Level 3 | First-lien senior secured debt investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: 10,949,467,000 12,009,907,000
Level 3 | First-lien senior secured debt investments | Yield Analysis    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 10,354,815,000 $ 11,273,964,000
Level 3 | First-lien senior secured debt investments | Yield Analysis | Minimum | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.069 0.063
Level 3 | First-lien senior secured debt investments | Yield Analysis | Maximum | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.279 0.201
Level 3 | First-lien senior secured debt investments | Yield Analysis | Weighted Average | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.106 0.096
Level 3 | First-lien senior secured debt investments | Transaction    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 426,356,000 $ 536,599,000
Level 3 | First-lien senior secured debt investments | Transaction | Minimum | Transaction Price    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.978 0.990
Level 3 | First-lien senior secured debt investments | Transaction | Maximum | Transaction Price    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 1.000 0.998
Level 3 | First-lien senior secured debt investments | Transaction | Weighted Average | Transaction Price    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.992 0.993
Level 3 | First-lien senior secured debt investments | Recovery Analysis    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 168,296,000  
Level 3 | First-lien senior secured debt investments | Recovery Analysis | Minimum | Recovery Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.000  
Level 3 | First-lien senior secured debt investments | Recovery Analysis | Maximum | Recovery Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 1.000  
Level 3 | First-lien senior secured debt investments | Recovery Analysis | Weighted Average | Recovery Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.535  
Level 3 | First-lien senior secured debt investments | Collateral Analysis    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value:   $ 199,344,000
Level 3 | First-lien senior secured debt investments | Collateral Analysis | Minimum | Recovery Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average)   0.000
Level 3 | First-lien senior secured debt investments | Collateral Analysis | Maximum | Recovery Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average)   1.072
Level 3 | First-lien senior secured debt investments | Collateral Analysis | Weighted Average | Recovery Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average)   0.595
Level 3 | Second-lien senior secured debt investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 623,238,000 $ 801,281,000
Level 3 | Second-lien senior secured debt investments | Yield Analysis    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 618,915,000 $ 801,281,000
Level 3 | Second-lien senior secured debt investments | Yield Analysis | Minimum | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.112 0.097
Level 3 | Second-lien senior secured debt investments | Yield Analysis | Maximum | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.550 0.624
Level 3 | Second-lien senior secured debt investments | Yield Analysis | Weighted Average | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.228 0.189
Level 3 | Second-lien senior secured debt investments | Recovery Analysis    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 4,323,000  
Level 3 | Second-lien senior secured debt investments | Recovery Analysis | Minimum | Recovery Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.033  
Level 3 | Second-lien senior secured debt investments | Recovery Analysis | Maximum | Recovery Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.033  
Level 3 | Second-lien senior secured debt investments | Recovery Analysis | Weighted Average | Recovery Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.033  
Level 3 | Unsecured Debt    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 389,154,000 $ 399,962,000
Level 3 | Unsecured Debt | Yield Analysis    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 372,546,000 $ 390,845,000
Level 3 | Unsecured Debt | Yield Analysis | Minimum | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.055 0.055
Level 3 | Unsecured Debt | Yield Analysis | Maximum | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.187 0.176
Level 3 | Unsecured Debt | Yield Analysis | Weighted Average | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.137 0.126
Level 3 | Unsecured Debt | Recovery Analysis    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 7,026,000  
Level 3 | Unsecured Debt | Recovery Analysis | Minimum | Recovery Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.710  
Level 3 | Unsecured Debt | Recovery Analysis | Maximum | Recovery Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.710  
Level 3 | Unsecured Debt | Recovery Analysis | Weighted Average | Recovery Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.710  
Level 3 | Unsecured Debt | Market Approach    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 9,582,000 $ 9,117,000
Level 3 | Unsecured Debt | Market Approach | Minimum | EBITDA Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 12.0 12.0
Level 3 | Unsecured Debt | Market Approach | Maximum | EBITDA Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 12.0 12.0
Level 3 | Unsecured Debt | Market Approach | Weighted Average | EBITDA Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 12.0 12.0
Level 3 | Specialty finance debt investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 178,964,000 $ 157,297,000
Level 3 | Specialty finance debt investments | Yield Analysis    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value:   $ 157,297,000
Level 3 | Specialty finance debt investments | Yield Analysis | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 178,964,000  
Level 3 | Specialty finance debt investments | Yield Analysis | Minimum | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.127 0.116
Level 3 | Specialty finance debt investments | Yield Analysis | Maximum | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.127 0.116
Level 3 | Specialty finance debt investments | Yield Analysis | Weighted Average | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.127 0.116
Level 3 | Preferred    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 275,703,000 $ 568,977,000
Level 3 | Preferred | Yield Analysis    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value:   $ 559,595,000
Level 3 | Preferred | Yield Analysis | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 229,748,000  
Level 3 | Preferred | Yield Analysis | Minimum | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.135 0.116
Level 3 | Preferred | Yield Analysis | Maximum | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.600 0.353
Level 3 | Preferred | Yield Analysis | Weighted Average | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.243 0.161
Level 3 | Preferred | Recovery Analysis | Recovery Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 16,465,000  
Level 3 | Preferred | Recovery Analysis | Minimum | Recovery Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.730  
Level 3 | Preferred | Recovery Analysis | Maximum | Recovery Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.730  
Level 3 | Preferred | Recovery Analysis | Weighted Average | Recovery Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.730  
Level 3 | Preferred | Market Approach    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 29,215,000  
Level 3 | Preferred | Market Approach | EBITDA Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value:   $ 9,171,000
Level 3 | Preferred | Market Approach | Revenue Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 275,000 $ 211,000
Level 3 | Preferred | Market Approach | Minimum | EBITDA Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 12.8 128.9
Level 3 | Preferred | Market Approach | Minimum | Revenue Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 12.8 11.3
Level 3 | Preferred | Market Approach | Maximum | EBITDA Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 12.8 128.9
Level 3 | Preferred | Market Approach | Maximum | Revenue Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 12.8 11.3
Level 3 | Preferred | Market Approach | Weighted Average | EBITDA Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 12.8 128.9
Level 3 | Preferred | Market Approach | Weighted Average | Revenue Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 12.8 11.3
Level 3 | Common equity investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 561,447,000 $ 520,542,000
Level 3 | Common equity investments | Yield Analysis | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 14,913,000 $ 14,020,000
Level 3 | Common equity investments | Yield Analysis | Minimum | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.084 0.085
Level 3 | Common equity investments | Yield Analysis | Maximum | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.084 0.085
Level 3 | Common equity investments | Yield Analysis | Weighted Average | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.084 0.085
Level 3 | Common equity investments | Transaction | Transaction Price    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 8,371,000  
Level 3 | Common equity investments | Transaction | Minimum | Transaction Price    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 1.000  
Level 3 | Common equity investments | Transaction | Maximum | Transaction Price    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 1.904  
Level 3 | Common equity investments | Transaction | Weighted Average | Transaction Price    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 1.026  
Level 3 | Common equity investments | Market Approach | Transaction Price    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value:   $ 21,679,000
Level 3 | Common equity investments | Market Approach | EBITDA Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 479,797,000 388,838,000
Level 3 | Common equity investments | Market Approach | Revenue Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: 47,648,000 45,461,000
Level 3 | Common equity investments | Market Approach | Gross Profit Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 203,000 166,000
Level 3 | Common equity investments | Market Approach | Market Adjustment Factor    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value:   $ 6,105,000
Level 3 | Common equity investments | Market Approach | Minimum | Transaction Price    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average)   96.84
Level 3 | Common equity investments | Market Approach | Minimum | EBITDA Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 3.8 4.0
Level 3 | Common equity investments | Market Approach | Minimum | Revenue Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 5.5 6.3
Level 3 | Common equity investments | Market Approach | Minimum | Gross Profit Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 10.0 9.0
Level 3 | Common equity investments | Market Approach | Minimum | Market Adjustment Factor    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average)   0.000
Level 3 | Common equity investments | Market Approach | Maximum | Transaction Price    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average)   96.84
Level 3 | Common equity investments | Market Approach | Maximum | EBITDA Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 27.8 17.9
Level 3 | Common equity investments | Market Approach | Maximum | Revenue Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 47.5 13.0
Level 3 | Common equity investments | Market Approach | Maximum | Gross Profit Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 10.0 9.0
Level 3 | Common equity investments | Market Approach | Maximum | Market Adjustment Factor    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average)   0.000
Level 3 | Common equity investments | Market Approach | Weighted Average | Transaction Price    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average)   96.84
Level 3 | Common equity investments | Market Approach | Weighted Average | EBITDA Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 7.8 7.7
Level 3 | Common equity investments | Market Approach | Weighted Average | Revenue Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 8.6 10.7
Level 3 | Common equity investments | Market Approach | Weighted Average | Gross Profit Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 10.0 9.0
Level 3 | Common equity investments | Market Approach | Weighted Average | Market Adjustment Factor    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average)   0
Level 3 | Common equity investments | Discounted Cash Flow Analysis | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 10,515,000  
Level 3 | Common equity investments | Discounted Cash Flow Analysis | Minimum | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.086  
Level 3 | Common equity investments | Discounted Cash Flow Analysis | Maximum | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.121  
Level 3 | Common equity investments | Discounted Cash Flow Analysis | Weighted Average | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.102  
Level 3 | Common equity investments | Recent Transaction | Transaction Price    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value:   $ 43,926,000
Level 3 | Common equity investments | Recent Transaction | Minimum | Transaction Price    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average)   1.000
Level 3 | Common equity investments | Recent Transaction | Maximum | Transaction Price    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average)   1.000
Level 3 | Common equity investments | Recent Transaction | Weighted Average | Transaction Price    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average)   1.000
Level 3 | Common equity investments | Option Pricing Model | Volatility    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value:   $ 347,000
Level 3 | Common equity investments | Option Pricing Model | Minimum | Volatility    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average)   0.600
Level 3 | Common equity investments | Option Pricing Model | Maximum | Volatility    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average)   0.700
Level 3 | Common equity investments | Option Pricing Model | Weighted Average | Volatility    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average)   0.700
Level 3 | Specialty finance equity investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 1,041,992,000 $ 1,114,178,000
Level 3 | Specialty finance equity investments | Yield Analysis | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 5,368,000 $ 6,657,000
Level 3 | Specialty finance equity investments | Yield Analysis | Minimum | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.121 0.115
Level 3 | Specialty finance equity investments | Yield Analysis | Maximum | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.121 0.115
Level 3 | Specialty finance equity investments | Yield Analysis | Weighted Average | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.121 0.115
Level 3 | Specialty finance equity investments | Market Approach    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value:   $ 94,930,000
Level 3 | Specialty finance equity investments | Market Approach | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 606,180,000  
Level 3 | Specialty finance equity investments | Market Approach | Recovery Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: 96,938,000  
Level 3 | Specialty finance equity investments | Market Approach | EBITDA Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value:   607,284,000
Level 3 | Specialty finance equity investments | Market Approach | AUM Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 302,327,000 $ 403,170,000
Level 3 | Specialty finance equity investments | Market Approach | Minimum | Recovery Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 1.113  
Level 3 | Specialty finance equity investments | Market Approach | Minimum | EBITDA Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average)   1.3
Level 3 | Specialty finance equity investments | Market Approach | Minimum | AUM Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 1.0 1.1
Level 3 | Specialty finance equity investments | Market Approach | Maximum | Recovery Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 1.518  
Level 3 | Specialty finance equity investments | Market Approach | Maximum | AUM Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 1.0  
Level 3 | Specialty finance equity investments | Market Approach | Weighted Average | Recovery Rate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 1.370  
Level 3 | Specialty finance equity investments | Market Approach | Weighted Average | AUM Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 1.0 1.1
Level 3 | Specialty finance equity investments | Discounted Cash Flow Analysis | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value: $ 31,179,000  
Level 3 | Specialty finance equity investments | Discounted Cash Flow Analysis | Book Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments at fair value:   $ 2,137,000
Level 3 | Specialty finance equity investments | Discounted Cash Flow Analysis | Minimum | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.110  
Level 3 | Specialty finance equity investments | Discounted Cash Flow Analysis | Minimum | Book Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average)   0.200
Level 3 | Specialty finance equity investments | Discounted Cash Flow Analysis | Maximum | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.200  
Level 3 | Specialty finance equity investments | Discounted Cash Flow Analysis | Maximum | Book Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average)   0.200
Level 3 | Specialty finance equity investments | Discounted Cash Flow Analysis | Weighted Average | Market Yield    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 0.116  
Level 3 | Specialty finance equity investments | Discounted Cash Flow Analysis | Weighted Average | Book Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average)   0.200
Level 3 | Specialty finance equity investments | Book Multiple | Minimum | Book Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 1.2  
Level 3 | Specialty finance equity investments | Book Multiple | Maximum | Book Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 1.2  
Level 3 | Specialty finance equity investments | Book Multiple | Weighted Average | Book Multiple    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Range (Weighted Average) 1.2  
[1] Certain portfolio company investments are subject to contractual restrictions on sales. Refer to footnote 30 for additional information on the Company’s restricted securities.
[2] Unless otherwise indicated, the Company’s portfolio companies are pledged as collateral supporting the amounts outstanding under the Revolving Credit Facility, SPV Asset Facilities and CLOs. See “Note 5 — Debt.”
[3] Certain portfolio company investments are subject to contractual restrictions on sales. Refer to footnote 30 for additional information on the Company’s restricted securities.
[4] Unless otherwise indicated, the Company’s portfolio companies are pledged as collateral supporting the amounts outstanding under the Revolving Credit Facility, SPV Asset Facilities and CLOs. See “Note 5 — Debt.”