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Investment Portfolio - Credit Opportunities Partners JV, LLC Portfolio (Details)
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Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Percent of net assets 218.80% 218.80% 218.80% 218.80% 218.80% 218.80% 218.80% 219.30% 219.30% 219.30% 219.30% 219.30% 219.30% 219.30%  
Amortized Cost $ 16,182,600,000             $ 16,314,100,000              
Fair Value $ (15,277,100,000)             $ (15,377,300,000) [1]              
Liabilities in excess of other assets percentage 118.80% 118.80% 118.80% 118.80% 118.80% 118.80% 118.80% 119.30% 119.30% 119.30% 119.30% 119.30% 119.30% 119.30%  
Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Percent of net assets 222.80% 222.80% 222.80% 222.80% 222.80% 222.80% 222.80% 218.50% 218.50% 218.50% 218.50% 218.50% 218.50% 218.50%  
Amortized Cost $ 3,779,000,000             $ 3,755,500,000              
Fair Value (3,556,300,000)             (3,562,900,000)              
Foreign currency forward contracts $ 2,800,000             $ 11,900,000              
Liabilities in excess of other assets percentage 0.20% 0.20% 0.20% 0.20% 0.20% 0.20% 0.20% 0.70% 0.70% 0.70% 0.70% 0.70% 0.70% 0.70%  
LIBOR                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 5.19% 5.19% 5.19% 5.19% 5.19% 5.19% 5.19% 4.77% 4.77% 4.77% 4.77% 4.77% 4.77% 4.77%  
LIBOR | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 5.19% 5.19% 5.19% 5.19% 5.19% 5.19% 5.19%                
Variable rate               4.77% 4.77% 4.77% 4.77% 4.77% 4.77% 4.77%  
EURIBOR                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 3.04% 3.04% 3.04% 3.04% 3.04% 3.04% 3.04%                
EURIBOR | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 3.04% 3.04% 3.04% 3.04% 3.04% 3.04% 3.04%                
Variable rate               2.13% 2.13% 2.13% 2.13% 2.13% 2.13% 2.13%  
CDOR                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 5.03% 5.03% 5.03% 5.03% 5.03% 5.03% 5.03% 4.94% 4.94% 4.94% 4.94% 4.94% 4.94% 4.94%  
CDOR | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 5.03% 5.03% 5.03% 5.03% 5.03% 5.03% 5.03%                
Variable rate               4.94% 4.94% 4.94% 4.94% 4.94% 4.94% 4.94%  
BBSY                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 3.77% 3.77% 3.77% 3.77% 3.77% 3.77% 3.77%                
BBSY | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 3.77% 3.77% 3.77% 3.77% 3.77% 3.77% 3.77%                
REIBOR                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 8.25% 8.25% 8.25% 8.25% 8.25% 8.25% 8.25% 6.55% 6.55% 6.55% 6.55% 6.55% 6.55% 6.55%  
REIBOR | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 8.25% 8.25% 8.25% 8.25% 8.25% 8.25% 8.25%                
Variable rate               6.55% 6.55% 6.55% 6.55% 6.55% 6.55% 6.55%  
STIBOR                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 3.36% 3.36% 3.36% 3.36% 3.36% 3.36% 3.36% 2.70% 2.70% 2.70% 2.70% 2.70% 2.70% 2.70%  
STIBOR | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 3.36% 3.36% 3.36% 3.36% 3.36% 3.36% 3.36%                
Variable rate               2.70% 2.70% 2.70% 2.70% 2.70% 2.70% 2.70%  
SONIA | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 4.18% 4.18% 4.18% 4.18% 4.18% 4.18% 4.18%                
Variable rate               3.43% 3.43% 3.43% 3.43% 3.43% 3.43% 3.43%  
SOFR | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 4.91% 4.91% 4.91% 4.91% 4.91% 4.91% 4.91%                
Pime                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%  
Pime | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%                
Variable rate               7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%  
Bank Bill Swap Bid Rate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               3.32% 3.32% 3.32% 3.32% 3.32% 3.32% 3.32%  
Bank Bill Swap Bid Rate | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               3.32% 3.32% 3.32% 3.32% 3.32% 3.32% 3.32%  
Secured Overnight Financing Rate (SOFR)                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 4.91% 4.91% 4.91% 4.91% 4.91% 4.91% 4.91% 4.59% 4.59% 4.59% 4.59% 4.59% 4.59% 4.59%  
Secured Overnight Financing Rate (SOFR) | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               4.59% 4.59% 4.59% 4.59% 4.59% 4.59% 4.59%  
Net Senior Secured Loans—First Lien                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Percent of net assets 133.50% [2] 133.50% [2] 133.50% [2] 133.50% [2] 133.50% [2] 133.50% [2] 133.50% [2] 132.30% [3] 132.30% [3] 132.30% [3] 132.30% [3] 132.30% [3] 132.30% [3] 132.30% [3]  
Amortized Cost $ 9,635,400,000             $ 9,607,500,000              
Fair Value $ (9,320,400,000) [4]             $ (9,278,000,000)              
Net Senior Secured Loans—First Lien | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Percent of net assets 152.90% 152.90% 152.90% 152.90% 152.90% 152.90% 152.90% 148.10% 148.10% 148.10% 148.10% 148.10% 148.10% 148.10%  
Amortized Cost $ 2,542,300,000             $ 2,519,500,000              
Fair Value (2,440,800,000)             (2,414,900,000)              
Funded, Senior Secured Loans—First Lien                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Amortized Cost 10,518,900,000             10,515,600,000              
Fair Value (10,203,900,000) [4]             (10,186,500,000) [1]              
Funded, Senior Secured Loans—First Lien | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Amortized Cost 2,545,900,000             2,522,800,000              
Fair Value (2,444,400,000)             (2,418,200,000)              
Unfunded, Senior Secured Loans—First Lien                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Amortized Cost 883,500,000             908,100,000              
Fair Value (883,500,000) [4]             (908,100,000) [1]              
Unfunded, Senior Secured Loans—First Lien | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Amortized Cost 3,600,000             3,300,000              
Fair Value $ (3,600,000)             $ (3,300,000)              
Net Senior Secured Loans—Second Lien                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Percent of net assets 16.80% [2] 16.80% [2] 16.80% [2] 16.80% [2] 16.80% [2] 16.80% [2] 16.80% [2] 17.00% [3] 17.00% [3] 17.00% [3] 17.00% [3] 17.00% [3] 17.00% [3] 17.00% [3]  
Amortized Cost $ 1,279,600,000             $ 1,299,200,000              
Fair Value $ (1,172,100,000) [4]             $ (1,194,500,000) [1]              
Net Senior Secured Loans—Second Lien | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Percent of net assets 23.00% 23.00% 23.00% 23.00% 23.00% 23.00% 23.00% 23.60% 23.60% 23.60% 23.60% 23.60% 23.60% 23.60%  
Amortized Cost $ 459,700,000             $ 459,100,000              
Fair Value (367,000,000.0)             (385,000,000.0)              
Other Senior Secured Debt                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Amortized Cost 152,000,000             152,000,000              
Fair Value $ (107,000,000)             $ (110,000,000)              
Other Senior Secured Debt | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Percent of net assets 1.20% 1.20% 1.20% 1.20% 1.20% 1.20% 1.20% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30%  
Amortized Cost $ 25,100,000             $ 25,000,000.0              
Fair Value $ (18,800,000)             $ (20,900,000)              
Net Subordinated Debt                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Percent of net assets 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 3.80% [3] 3.80% [3] 3.80% [3] 3.80% [3] 3.80% [3] 3.80% [3] 3.80% [3]  
Amortized Cost $ 399,000,000.0             $ 383,900,000              
Fair Value $ (280,500,000) [4]             $ (265,000,000.0) [1]              
Net Subordinated Debt | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Percent of net assets 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30%  
Amortized Cost $ 21,000,000.0             $ 21,000,000.0              
Fair Value $ (21,000,000.0)             $ (21,100,000)              
Net Asset Based Finance                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Percent of net assets 25.50% [2] 25.50% [2] 25.50% [2] 25.50% [2] 25.50% [2] 25.50% [2] 25.50% [2] 27.10% [3] 27.10% [3] 27.10% [3] 27.10% [3] 27.10% [3] 27.10% [3] 27.10% [3]  
Amortized Cost $ 1,916,200,000             $ 2,023,600,000              
Fair Value $ (1,778,500,000) [4]             $ (1,902,500,000) [1]              
Net Asset Based Finance | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Percent of net assets 33.80% 33.80% 33.80% 33.80% 33.80% 33.80% 33.80% 33.20% 33.20% 33.20% 33.20% 33.20% 33.20% 33.20%  
Amortized Cost $ 549,600,000             $ 550,500,000              
Fair Value (540,000,000.0)             (542,000,000.0)              
Equity/Other                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Amortized Cost 1,229,000,000             1,276,000,000              
Fair Value $ (1,222,000,000)             $ (1,199,000,000)              
Equity/Other | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Percent of net assets 10.60% 10.60% 10.60% 10.60% 10.60% 10.60% 10.60% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%  
Amortized Cost $ 181,300,000             $ 180,400,000              
Fair Value $ (168,700,000)             (179,000,000.0)              
Investment, Identifier [Axis]: Affordable Care Inc, Common Stock, Equity/Other                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               (49,900,000)             $ (52,100,000)
Investment, Identifier [Axis]: Belk Inc, Senior Secured Loans—Second Lien                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               (3,300,000)             (6,700,000)
Investment, Identifier [Axis]: Fairway Group Holdings Corp , Senior Secured Loans—Second Lien                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               0             0
Investment, Identifier [Axis]: Fronton BV, Common Stock, Equity/Other                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               (1,000,000.0)             (1,400,000)
Investment, Identifier [Axis]: Home Partners JV 2, Private Equity 1, Asset Based Finance                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               (200,000)             (100,000)
Investment, Identifier [Axis]: Home Partners JV 2, Private Equity 2, Asset Based Finance -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               (5,000,000.0)             (1,600,000)
Investment, Identifier [Axis]: Home Partners JV, Private Equity, Asset Based Finance -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               0             (9,400,000)
Investment, Identifier [Axis]: Home Partners JV, Structured Mezzanine, Asset Based Finance                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               0             (90,400,000)
Investment, Identifier [Axis]: Jet Edge International LLC, Preferred Stock, Asset Based Finance -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               0             (16,800,000)
Investment, Identifier [Axis]: Micronics Filtration Holdings Inc, Preferred Stock, Series A, Equity/Other                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               0             (100,000)
Investment, Identifier [Axis]: Micronics Filtration Holdings Inc, Preferred Stock, Series B PIK 2, Equity/Other                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               0             (11,900,000)
Investment, Identifier [Axis]: Micronics Filtration Holdings Inc, Preferred Stock, Series B PIK, Equity/Other                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               0             (400,000)
Investment, Identifier [Axis]: Micronics Filtration Holdings Inc, Preferred Stock, Series C PIK, Equity/Other                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               0             (6,200,000)
Investment, Identifier [Axis]: Petroplex Acidizing Inc, Warrant, Equity/Other                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               0             0
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc, Senior Secured Loans—Second Lien                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value [5]               $ 0             (8,300,000)
Investment, Identifier [Axis]: 3Pillar Global Inc, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [8],[9],[10],[11],[12] 6.00% [8],[9],[10],[11],[12] 6.00% [8],[9],[10],[11],[12] 6.00% [8],[9],[10],[11],[12] 6.00% [8],[9],[10],[11],[12] 6.00% [8],[9],[10],[11],[12] 6.00% [8],[9],[10],[11],[12]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [9],[10],[11],[12] 0.80% [9],[10],[11],[12] 0.80% [9],[10],[11],[12] 0.80% [9],[10],[11],[12] 0.80% [9],[10],[11],[12] 0.80% [9],[10],[11],[12] 0.80% [9],[10],[11],[12]  
Principal amount $ 600,000 [7],[13]             $ 101,000,000.0 [9],[10],[11],[12],[14]              
Amortized Cost 600,000 [7]             100,200,000 [9],[10],[11],[12]              
Fair Value $ (600,000) [4],[7]             $ (96,700,000) [1],[9],[10],[11],[12]              
Investment, Identifier [Axis]: 3Pillar Global Inc, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[15],[16],[17] 6.00% [6],[15],[16],[17] 6.00% [6],[15],[16],[17] 6.00% [6],[15],[16],[17] 6.00% [6],[15],[16],[17] 6.00% [6],[15],[16],[17] 6.00% [6],[15],[16],[17] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18]  
Base Rate Floor 0.80% [6],[15],[16],[17] 0.80% [6],[15],[16],[17] 0.80% [6],[15],[16],[17] 0.80% [6],[15],[16],[17] 0.80% [6],[15],[16],[17] 0.80% [6],[15],[16],[17] 0.80% [6],[15],[16],[17] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 95,100,000 [13],[15],[16],[17]             $ 9,200,000 [14],[18]              
Amortized Cost 94,200,000 [15],[16],[17]             9,200,000 [18]              
Fair Value $ (92,300,000) [4],[15],[16],[17]             $ (8,800,000) [1],[18]              
Investment, Identifier [Axis]: 3Pillar Global Inc, Software & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 6,600,000 [7],[13]             $ 24,900,000 [14],[18]              
Amortized Cost 6,600,000 [7]             24,900,000 [18]              
Fair Value $ (6,400,000) [4],[7]             $ (23,800,000) [1],[18]              
Investment, Identifier [Axis]: 3Pillar Global Inc, Software & Services 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base Rate Floor [6],[19] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[19] $ 8,600,000                            
Amortized Cost [19] 8,600,000                            
Fair Value [4],[19] $ (8,300,000)                            
Investment, Identifier [Axis]: 3Pillar Global Inc, Software & Services 5                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base Rate Floor [6],[19] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[19] $ 24,000,000.0                            
Amortized Cost [19] 24,000,000.0                            
Fair Value [4],[19] $ (23,300,000)                            
Investment, Identifier [Axis]: 48Forty Solutions LLC, Commercial & Professional Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 19,300,000             $ 19,400,000              
Amortized Cost 19,100,000             19,200,000              
Fair Value $ (19,100,000)             $ (18,800,000)              
Investment, Identifier [Axis]: 48Forty Solutions LLC, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[7],[16],[17],[20],[21] 5.50% [6],[7],[16],[17],[20],[21] 5.50% [6],[7],[16],[17],[20],[21] 5.50% [6],[7],[16],[17],[20],[21] 5.50% [6],[7],[16],[17],[20],[21] 5.50% [6],[7],[16],[17],[20],[21] 5.50% [6],[7],[16],[17],[20],[21] 5.50% [8],[9],[10],[11],[22],[23] 5.50% [8],[9],[10],[11],[22],[23] 5.50% [8],[9],[10],[11],[22],[23] 5.50% [8],[9],[10],[11],[22],[23] 5.50% [8],[9],[10],[11],[22],[23] 5.50% [8],[9],[10],[11],[22],[23] 5.50% [8],[9],[10],[11],[22],[23]  
Base Rate Floor 1.00% [6],[7],[16],[17],[20],[21] 1.00% [6],[7],[16],[17],[20],[21] 1.00% [6],[7],[16],[17],[20],[21] 1.00% [6],[7],[16],[17],[20],[21] 1.00% [6],[7],[16],[17],[20],[21] 1.00% [6],[7],[16],[17],[20],[21] 1.00% [6],[7],[16],[17],[20],[21] 1.00% [9],[10],[11],[22],[23] 1.00% [9],[10],[11],[22],[23] 1.00% [9],[10],[11],[22],[23] 1.00% [9],[10],[11],[22],[23] 1.00% [9],[10],[11],[22],[23] 1.00% [9],[10],[11],[22],[23] 1.00% [9],[10],[11],[22],[23]  
Principal amount $ 182,200,000 [7],[13],[16],[17],[20],[21]             $ 182,700,000 [9],[10],[11],[14],[22],[23]              
Amortized Cost 180,800,000 [7],[16],[17],[20],[21]             181,200,000 [9],[10],[11],[22],[23]              
Fair Value $ (180,600,000) [4],[7],[16],[17],[20],[21]             $ (177,800,000) [1],[9],[10],[11],[22],[23]              
Investment, Identifier [Axis]: 48Forty Solutions LLC, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 1,100,000 [7],[13]             $ 10,600,000 [14],[18]              
Amortized Cost 1,100,000 [7]             10,600,000 [18]              
Fair Value $ (1,100,000) [4],[7]             $ (10,300,000) [1],[18]              
Investment, Identifier [Axis]: 48Forty Solutions LLC, Commercial & Professional Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base Rate Floor [6],[19] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[19] $ 9,600,000                            
Amortized Cost [19] 9,600,000                            
Fair Value [4],[19] $ (9,500,000)                            
Investment, Identifier [Axis]: 5 Arch Income Fund 2 LLC, Diversified Financials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate [8],[24],[25],[26],[27],[28]               9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%  
Principal amount [14],[24],[25],[26],[27],[28]               $ 95,500,000              
Amortized Cost [24],[25],[26],[27],[28]               69,900,000              
Fair Value [1],[24],[25],[26],[27],[28]               (52,500,000)              
Investment, Identifier [Axis]: 5 Arch Income Fund 2 LLC, Financial Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[29],[30],[31],[32],[33] 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%                
Principal amount [13],[29],[30],[31],[32],[33] $ 88,600,000                            
Amortized Cost [29],[30],[31],[32],[33] 64,800,000                            
Fair Value [4],[29],[30],[31],[32],[33] (37,500,000)                            
Investment, Identifier [Axis]: 801 5th Ave, Seattle, Private Equity                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (5,200,000)             $ (6,300,000)             (23,100,000)
Investment, Identifier [Axis]: 801 5th Ave, Seattle, Private Equity, Equity Real Estate Investment Trusts (REITs)                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[13],[32],[33],[34] 8,516,891 8,516,891 8,516,891 8,516,891 8,516,891 8,516,891 8,516,891                
Amortized Cost [7],[32],[33],[34] $ 14,000,000.0                            
Fair Value [4],[7],[32],[33],[34] (5,200,000)                            
Investment, Identifier [Axis]: 801 5th Ave, Seattle, Private Equity, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [11],[14],[27],[28],[35]               8,516,891 8,516,891 8,516,891 8,516,891 8,516,891 8,516,891 8,516,891  
Amortized Cost [11],[27],[28],[35]               $ 14,000,000.0              
Fair Value [1],[11],[27],[28],[35]               (6,300,000)              
Investment, Identifier [Axis]: 801 5th Ave, Seattle, Structure Mezzanine                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (58,900,000)             $ (58,900,000)             (57,200,000)
Investment, Identifier [Axis]: 801 5th Ave, Seattle, Structure Mezzanine, Equity Real Estate Investment Trusts (REITs)                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[33],[34] 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%                
Rate, PIK [6],[7],[33],[34] 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00%                
Rate, Max PIK [6],[7],[33],[34] 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00%                
Principal amount [7],[13],[33],[34] $ 58,900,000                            
Amortized Cost [7],[33],[34] 57,100,000                            
Fair Value [4],[7],[33],[34] (58,900,000)                            
Investment, Identifier [Axis]: 801 5th Ave, Seattle, Structure Mezzanine, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11],[28],[35]               8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%  
Rate, PIK [8],[11],[28],[35]               3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00%  
Rate, Max PIK [8],[11],[28],[35]               3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00%  
Principal amount [11],[14],[28],[35]               $ 58,900,000              
Amortized Cost [11],[28],[35]               57,000,000.0              
Fair Value [1],[11],[28],[35]               (58,900,000)              
Investment, Identifier [Axis]: ATX Networks Corp 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value (55,600,000)             (40,600,000)             (46,800,000)
Investment, Identifier [Axis]: ATX Networks Corp 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (31,300,000)             $ (21,900,000)             (7,100,000)
Investment, Identifier [Axis]: ATX Networks Corp, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.50% [6],[7],[33],[34],[36] 7.50% [6],[7],[33],[34],[36] 7.50% [6],[7],[33],[34],[36] 7.50% [6],[7],[33],[34],[36] 7.50% [6],[7],[33],[34],[36] 7.50% [6],[7],[33],[34],[36] 7.50% [6],[7],[33],[34],[36] 7.50% [8],[11],[28],[35],[37] 7.50% [8],[11],[28],[35],[37] 7.50% [8],[11],[28],[35],[37] 7.50% [8],[11],[28],[35],[37] 7.50% [8],[11],[28],[35],[37] 7.50% [8],[11],[28],[35],[37] 7.50% [8],[11],[28],[35],[37]  
Base Rate Floor 1.00% [6],[7],[33],[34],[36] 1.00% [6],[7],[33],[34],[36] 1.00% [6],[7],[33],[34],[36] 1.00% [6],[7],[33],[34],[36] 1.00% [6],[7],[33],[34],[36] 1.00% [6],[7],[33],[34],[36] 1.00% [6],[7],[33],[34],[36] 1.00% [11],[28],[35],[37] 1.00% [11],[28],[35],[37] 1.00% [11],[28],[35],[37] 1.00% [11],[28],[35],[37] 1.00% [11],[28],[35],[37] 1.00% [11],[28],[35],[37] 1.00% [11],[28],[35],[37]  
Principal amount $ 55,600,000 [7],[13],[33],[34],[36]             $ 40,600,000 [11],[14],[28],[35],[37]              
Amortized Cost 55,600,000 [7],[33],[34],[36]             40,600,000 [11],[28],[35],[37]              
Fair Value $ (55,600,000) [4],[7],[33],[34],[36]             $ (40,600,000) [1],[11],[28],[35],[37]              
Investment, Identifier [Axis]: ATX Networks Corp, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 10.00% [7],[33],[34],[36] 10.00% [7],[33],[34],[36] 10.00% [7],[33],[34],[36] 10.00% [7],[33],[34],[36] 10.00% [7],[33],[34],[36] 10.00% [7],[33],[34],[36] 10.00% [7],[33],[34],[36] 10.00% [8],[11],[28],[35],[37],[38] 10.00% [8],[11],[28],[35],[37],[38] 10.00% [8],[11],[28],[35],[37],[38] 10.00% [8],[11],[28],[35],[37],[38] 10.00% [8],[11],[28],[35],[37],[38] 10.00% [8],[11],[28],[35],[37],[38] 10.00% [8],[11],[28],[35],[37],[38]  
Rate, Max PIK 10.00% [7],[33],[34],[36] 10.00% [7],[33],[34],[36] 10.00% [7],[33],[34],[36] 10.00% [7],[33],[34],[36] 10.00% [7],[33],[34],[36] 10.00% [7],[33],[34],[36] 10.00% [7],[33],[34],[36] 10.00% [8],[11],[28],[35],[37],[38] 10.00% [8],[11],[28],[35],[37],[38] 10.00% [8],[11],[28],[35],[37],[38] 10.00% [8],[11],[28],[35],[37],[38] 10.00% [8],[11],[28],[35],[37],[38] 10.00% [8],[11],[28],[35],[37],[38] 10.00% [8],[11],[28],[35],[37],[38]  
Principal amount $ 31,300,000 [7],[33],[34],[36]             $ 21,900,000 [11],[14],[28],[35],[37],[38]              
Amortized Cost 17,700,000 [7],[33],[34],[36]             8,400,000 [11],[28],[35],[37],[38]              
Fair Value (31,300,000) [7],[33],[34],[36]             (21,900,000) [1],[11],[28],[35],[37],[38]              
Investment, Identifier [Axis]: ATX Networks Corp, Class B-1 Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (5,000,000.0)             $ (5,000,000.0)             0
Investment, Identifier [Axis]: ATX Networks Corp, Class B-1 Common Stock, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 500 [7],[32],[33],[34] 500 [7],[32],[33],[34] 500 [7],[32],[33],[34] 500 [7],[32],[33],[34] 500 [7],[32],[33],[34] 500 [7],[32],[33],[34] 500 [7],[32],[33],[34] 500 [11],[27],[28],[35] 500 [11],[27],[28],[35] 500 [11],[27],[28],[35] 500 [11],[27],[28],[35] 500 [11],[27],[28],[35] 500 [11],[27],[28],[35] 500 [11],[27],[28],[35]  
Amortized Cost $ 5,000,000.0 [7],[32],[33],[34]             $ 5,000,000.0 [11],[27],[28],[35]              
Fair Value (5,000,000.0) [4],[7],[32],[33],[34]             (5,000,000.0) [1],[11],[27],[28],[35]              
Investment, Identifier [Axis]: ATX Networks Corp, Class B-2 Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (9,000,000.0)             $ (9,000,000.0)             0
Investment, Identifier [Axis]: ATX Networks Corp, Class B-2 Common Stock, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 900 [7],[32],[33],[34] 900 [7],[32],[33],[34] 900 [7],[32],[33],[34] 900 [7],[32],[33],[34] 900 [7],[32],[33],[34] 900 [7],[32],[33],[34] 900 [7],[32],[33],[34] 900 [11],[27],[28],[35] 900 [11],[27],[28],[35] 900 [11],[27],[28],[35] 900 [11],[27],[28],[35] 900 [11],[27],[28],[35] 900 [11],[27],[28],[35] 900 [11],[27],[28],[35]  
Amortized Cost $ 4,000,000.0 [7],[32],[33],[34]             $ 4,000,000.0 [11],[27],[28],[35]              
Fair Value (9,000,000.0) [4],[7],[32],[33],[34]             (9,000,000.0) [1],[11],[27],[28],[35]              
Investment, Identifier [Axis]: ATX Networks Corp, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (38,500,000)             $ (29,200,000)             0
Investment, Identifier [Axis]: ATX Networks Corp, Common Stock, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 5,578 [7],[32],[33],[34],[36] 5,578 [7],[32],[33],[34],[36] 5,578 [7],[32],[33],[34],[36] 5,578 [7],[32],[33],[34],[36] 5,578 [7],[32],[33],[34],[36] 5,578 [7],[32],[33],[34],[36] 5,578 [7],[32],[33],[34],[36] 4,214 [11],[27],[28],[35],[37],[38] 4,214 [11],[27],[28],[35],[37],[38] 4,214 [11],[27],[28],[35],[37],[38] 4,214 [11],[27],[28],[35],[37],[38] 4,214 [11],[27],[28],[35],[37],[38] 4,214 [11],[27],[28],[35],[37],[38] 4,214 [11],[27],[28],[35],[37],[38]  
Amortized Cost $ 9,900,000 [7],[32],[33],[34],[36]             $ 1,700,000 [11],[27],[28],[35],[37],[38]              
Fair Value $ (38,500,000) [4],[7],[32],[33],[34],[36]             $ (29,200,000) [1],[11],[27],[28],[35],[37],[38]              
Investment, Identifier [Axis]: AVF Parent LLC, Trade Claim, Retailing                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [11],[27]               44,507 44,507 44,507 44,507 44,507 44,507 44,507  
Amortized Cost [11],[27]               $ 0              
Fair Value [1],[11],[27]               $ 0              
Investment, Identifier [Axis]: Abaco Energy Technologies LLC, Common Stock, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 3,055,556 [7],[32] 3,055,556 [7],[32] 3,055,556 [7],[32] 3,055,556 [7],[32] 3,055,556 [7],[32] 3,055,556 [7],[32] 3,055,556 [7],[32] 3,055,556 [11],[27] 3,055,556 [11],[27] 3,055,556 [11],[27] 3,055,556 [11],[27] 3,055,556 [11],[27] 3,055,556 [11],[27] 3,055,556 [11],[27]  
Amortized Cost $ 200,000 [7],[32]             $ 200,000 [11],[27]              
Fair Value $ (600,000) [4],[7],[32]             $ (500,000) [1],[11],[27]              
Investment, Identifier [Axis]: Abaco Energy Technologies LLC, Preferred Stock, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 12,734,481 [7],[32] 12,734,481 [7],[32] 12,734,481 [7],[32] 12,734,481 [7],[32] 12,734,481 [7],[32] 12,734,481 [7],[32] 12,734,481 [7],[32] 12,734,481 [11],[27] 12,734,481 [11],[27] 12,734,481 [11],[27] 12,734,481 [11],[27] 12,734,481 [11],[27] 12,734,481 [11],[27] 12,734,481 [11],[27]  
Amortized Cost $ 1,500,000 [7],[32]             $ 1,500,000 [11],[27]              
Fair Value $ (4,000,000.0) [4],[7],[32]             $ (3,700,000) [1],[11],[27]              
Investment, Identifier [Axis]: Abacus JV, Private Equity, Insurance                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 47,045,141 [7],[13],[33] 47,045,141 [7],[13],[33] 47,045,141 [7],[13],[33] 47,045,141 [7],[13],[33] 47,045,141 [7],[13],[33] 47,045,141 [7],[13],[33] 47,045,141 [7],[13],[33] 49,223,047 [11],[14],[28] 49,223,047 [11],[14],[28] 49,223,047 [11],[14],[28] 49,223,047 [11],[14],[28] 49,223,047 [11],[14],[28] 49,223,047 [11],[14],[28] 49,223,047 [11],[14],[28]  
Amortized Cost $ 46,100,000 [7],[33]             $ 48,200,000 [11],[28]              
Fair Value $ (49,200,000) [4],[7],[33]             $ (53,300,000) [1],[11],[28]              
Investment, Identifier [Axis]: Abacus JV, Private Equity, Insurance | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 30,011,455 30,011,455 30,011,455 30,011,455 30,011,455 30,011,455 30,011,455 31,400,804 31,400,804 31,400,804 31,400,804 31,400,804 31,400,804 31,400,804  
Amortized Cost $ 30,800,000             $ 32,200,000              
Fair Value $ (31,400,000)             $ (34,000,000.0)              
Investment, Identifier [Axis]: Accelerator Investments Aggregator LP, Private Equity, Diversified Financials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [11],[14],[27],[28]               3,869,291 3,869,291 3,869,291 3,869,291 3,869,291 3,869,291 3,869,291  
Amortized Cost [11],[27],[28]               $ 4,500,000              
Fair Value [1],[11],[27],[28]               $ (3,400,000)              
Investment, Identifier [Axis]: Accelerator Investments Aggregator LP, Private Equity, Financial Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[13],[32],[33] 3,869,291 3,869,291 3,869,291 3,869,291 3,869,291 3,869,291 3,869,291                
Amortized Cost [7],[32],[33] $ 4,500,000                            
Fair Value [4],[7],[32],[33] $ (3,500,000)                            
Investment, Identifier [Axis]: Access CIG LLC, Commercial & Professional Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount $ 2,500,000             $ 2,500,000              
Amortized Cost 2,300,000             2,300,000              
Fair Value $ (2,300,000)             $ (2,200,000)              
Investment, Identifier [Axis]: Accuride Corp, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% [6],[17],[39] 5.25% [6],[17],[39] 5.25% [6],[17],[39] 5.25% [6],[17],[39] 5.25% [6],[17],[39] 5.25% [6],[17],[39] 5.25% [6],[17],[39] 5.25% [8],[10],[40] 5.25% [8],[10],[40] 5.25% [8],[10],[40] 5.25% [8],[10],[40] 5.25% [8],[10],[40] 5.25% [8],[10],[40] 5.25% [8],[10],[40]  
Base Rate Floor 1.00% [6],[17],[39] 1.00% [6],[17],[39] 1.00% [6],[17],[39] 1.00% [6],[17],[39] 1.00% [6],[17],[39] 1.00% [6],[17],[39] 1.00% [6],[17],[39] 1.00% [10],[40] 1.00% [10],[40] 1.00% [10],[40] 1.00% [10],[40] 1.00% [10],[40] 1.00% [10],[40] 1.00% [10],[40]  
Principal amount $ 8,900,000 [13],[17],[39]             $ 8,900,000 [10],[14],[40]              
Amortized Cost 8,500,000 [17],[39]             8,400,000 [10],[40]              
Fair Value $ (7,100,000) [4],[17],[39]             $ (7,600,000) [1],[10],[40]              
Investment, Identifier [Axis]: Accuride Corp, Capital Goods | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 20,700,000             $ 20,800,000              
Amortized Cost 20,400,000             20,400,000              
Fair Value $ (16,500,000)             $ (17,700,000)              
Investment, Identifier [Axis]: Advanced Dermatology & Cosmetic Surgery, Health Care Equipment & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[7],[21],[41] 6.50% [6],[7],[21],[41] 6.50% [6],[7],[21],[41] 6.50% [6],[7],[21],[41] 6.50% [6],[7],[21],[41] 6.50% [6],[7],[21],[41] 6.50% [6],[7],[21],[41] 6.50% [8],[11],[23],[42] 6.50% [8],[11],[23],[42] 6.50% [8],[11],[23],[42] 6.50% [8],[11],[23],[42] 6.50% [8],[11],[23],[42] 6.50% [8],[11],[23],[42] 6.50% [8],[11],[23],[42]  
Base Rate Floor 1.00% [6],[7],[21],[41] 1.00% [6],[7],[21],[41] 1.00% [6],[7],[21],[41] 1.00% [6],[7],[21],[41] 1.00% [6],[7],[21],[41] 1.00% [6],[7],[21],[41] 1.00% [6],[7],[21],[41] 1.00% [11],[23],[42] 1.00% [11],[23],[42] 1.00% [11],[23],[42] 1.00% [11],[23],[42] 1.00% [11],[23],[42] 1.00% [11],[23],[42] 1.00% [11],[23],[42]  
Principal amount $ 46,200,000 [7],[13],[21],[41]             $ 46,300,000 [11],[14],[23],[42]              
Amortized Cost 44,700,000 [7],[21],[41]             44,700,000 [11],[23],[42]              
Fair Value $ (45,500,000) [4],[7],[21],[41]             $ (45,600,000) [1],[11],[23],[42]              
Investment, Identifier [Axis]: Advanced Dermatology & Cosmetic Surgery, Health Care Equipment & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 3,600,000 [13],[19]             $ 2,200,000 [14],[18]              
Amortized Cost 3,600,000 [19]             2,200,000 [18]              
Fair Value $ (3,500,000) [4],[19]             $ (2,200,000) [1],[18]              
Investment, Identifier [Axis]: Advanced Dermatology & Cosmetic Surgery, Health Care Equipment & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 2,200,000 [13],[19]             $ 3,600,000 [14],[18]              
Amortized Cost 2,200,000 [19]             3,600,000 [18]              
Fair Value $ (2,200,000) [4],[19]             $ (3,500,000) [1],[18]              
Investment, Identifier [Axis]: Advanced Lighting Technologies Inc, Materials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK               16.00% 16.00% 16.00% 16.00% 16.00% 16.00% 16.00%  
Rate, Max PIK [8],[11],[24],[27]               16.00% 16.00% 16.00% 16.00% 16.00% 16.00% 16.00%  
Base Rate Floor [11],[24],[27]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [11],[14],[24],[27]               $ 13,500,000              
Amortized Cost [11],[24],[27]               10,500,000              
Fair Value [1],[11],[24],[27]               $ (3,400,000)              
Investment, Identifier [Axis]: Advania Sverige AB, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.10% [6],[7],[33] 6.10% [6],[7],[33] 6.10% [6],[7],[33] 6.10% [6],[7],[33] 6.10% [6],[7],[33] 6.10% [6],[7],[33] 6.10% [6],[7],[33] 6.10% [8],[11],[28] 6.10% [8],[11],[28] 6.10% [8],[11],[28] 6.10% [8],[11],[28] 6.10% [8],[11],[28] 6.10% [8],[11],[28] 6.10% [8],[11],[28]  
Rate, PIK 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [8],[11],[28] 0.00% [8],[11],[28] 0.00% [8],[11],[28] 0.00% [8],[11],[28] 0.00% [8],[11],[28] 0.00% [8],[11],[28] 0.00% [8],[11],[28]  
Rate, Max PIK 3.30% [6],[7],[33] 3.30% [6],[7],[33] 3.30% [6],[7],[33] 3.30% [6],[7],[33] 3.30% [6],[7],[33] 3.30% [6],[7],[33] 3.30% [6],[7],[33] 3.30% [8],[11],[28] 3.30% [8],[11],[28] 3.30% [8],[11],[28] 3.30% [8],[11],[28] 3.30% [8],[11],[28] 3.30% [8],[11],[28] 3.30% [8],[11],[28]  
Base Rate Floor 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28]  
Principal amount | kr   kr 933.6 [7],[13],[33]             kr 933.6 [11],[14],[28]            
Amortized Cost $ 106,200,000 [7],[33]             $ 106,100,000 [11],[28]              
Fair Value $ (87,700,000) [4],[7],[33]             $ (86,000,000.0) [1],[11],[28]              
Investment, Identifier [Axis]: Advania Sverige AB, Software & Services 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10%  
Rate, PIK 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Rate, Max PIK 3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | kr   kr 588.0             kr 588.0            
Amortized Cost $ 66,700,000             $ 66,600,000              
Fair Value $ (55,100,000)             $ (54,100,000)              
Investment, Identifier [Axis]: Advania Sverige AB, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.10% [6],[7],[33] 6.10% [6],[7],[33] 6.10% [6],[7],[33] 6.10% [6],[7],[33] 6.10% [6],[7],[33] 6.10% [6],[7],[33] 6.10% [6],[7],[33] 6.10% [8],[11],[28] 6.10% [8],[11],[28] 6.10% [8],[11],[28] 6.10% [8],[11],[28] 6.10% [8],[11],[28] 6.10% [8],[11],[28] 6.10% [8],[11],[28]  
Rate, PIK 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [8],[11],[28] 0.00% [8],[11],[28] 0.00% [8],[11],[28] 0.00% [8],[11],[28] 0.00% [8],[11],[28] 0.00% [8],[11],[28] 0.00% [8],[11],[28]  
Rate, Max PIK 3.30% [6],[7],[33] 3.30% [6],[7],[33] 3.30% [6],[7],[33] 3.30% [6],[7],[33] 3.30% [6],[7],[33] 3.30% [6],[7],[33] 3.30% [6],[7],[33] 3.30% [8],[11],[28] 3.30% [8],[11],[28] 3.30% [8],[11],[28] 3.30% [8],[11],[28] 3.30% [8],[11],[28] 3.30% [8],[11],[28] 3.30% [8],[11],[28]  
Base Rate Floor 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28]  
Principal amount | kr     kr 1,345.8 [7],[13],[33]             kr 1,345.8 [11],[14],[28]          
Amortized Cost $ 10,100,000 [7],[33]             $ 10,100,000 [11],[28]              
Fair Value $ (9,600,000) [4],[7],[33]             $ (9,200,000) [1],[11],[28]              
Investment, Identifier [Axis]: Advania Sverige AB, Software & Services 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10%  
Rate, PIK 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Rate, Max PIK 3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | kr     kr 1,644.9             kr 1,644.9          
Amortized Cost $ 12,800,000             $ 12,800,000              
Fair Value (11,600,000)             (11,200,000)              
Investment, Identifier [Axis]: Affordable Care Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (55,200,000)             $ (53,100,000)              
Investment, Identifier [Axis]: Affordable Care Inc, Health Care Equipment & Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Rate, PIK 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Rate, Max PIK               1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 76,200,000             $ 76,100,000              
Amortized Cost 75,700,000             75,600,000              
Fair Value $ (75,200,000)             $ (74,600,000)              
Investment, Identifier [Axis]: Affordable Care Inc, Health Care Equipment & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 4.50% [6],[7],[41],[43] 4.50% [6],[7],[41],[43] 4.50% [6],[7],[41],[43] 4.50% [6],[7],[41],[43] 4.50% [6],[7],[41],[43] 4.50% [6],[7],[41],[43] 4.50% [6],[7],[41],[43] 5.50% [8],[11],[42],[44] 5.50% [8],[11],[42],[44] 5.50% [8],[11],[42],[44] 5.50% [8],[11],[42],[44] 5.50% [8],[11],[42],[44] 5.50% [8],[11],[42],[44] 5.50% [8],[11],[42],[44]  
Rate, PIK 1.30% [6],[7],[41],[43] 1.30% [6],[7],[41],[43] 1.30% [6],[7],[41],[43] 1.30% [6],[7],[41],[43] 1.30% [6],[7],[41],[43] 1.30% [6],[7],[41],[43] 1.30% [6],[7],[41],[43] 0.00% [8],[11],[42],[44] 0.00% [8],[11],[42],[44] 0.00% [8],[11],[42],[44] 0.00% [8],[11],[42],[44] 0.00% [8],[11],[42],[44] 0.00% [8],[11],[42],[44] 0.00% [8],[11],[42],[44]  
Rate, Max PIK 1.30% [6],[7],[41],[43] 1.30% [6],[7],[41],[43] 1.30% [6],[7],[41],[43] 1.30% [6],[7],[41],[43] 1.30% [6],[7],[41],[43] 1.30% [6],[7],[41],[43] 1.30% [6],[7],[41],[43] 1.30% [8],[11],[42],[44] 1.30% [8],[11],[42],[44] 1.30% [8],[11],[42],[44] 1.30% [8],[11],[42],[44] 1.30% [8],[11],[42],[44] 1.30% [8],[11],[42],[44] 1.30% [8],[11],[42],[44]  
Base Rate Floor 0.80% [6],[7],[41],[43] 0.80% [6],[7],[41],[43] 0.80% [6],[7],[41],[43] 0.80% [6],[7],[41],[43] 0.80% [6],[7],[41],[43] 0.80% [6],[7],[41],[43] 0.80% [6],[7],[41],[43] 0.80% [11],[42],[44] 0.80% [11],[42],[44] 0.80% [11],[42],[44] 0.80% [11],[42],[44] 0.80% [11],[42],[44] 0.80% [11],[42],[44] 0.80% [11],[42],[44]  
Principal amount $ 56,400,000 [7],[13],[41],[43]             $ 53,600,000 [11],[14],[42],[44]              
Amortized Cost 56,100,000 [7],[41],[43]             53,300,000 [11],[42],[44]              
Fair Value $ (55,700,000) [4],[7],[41],[43]             $ (52,500,000) [1],[11],[42],[44]              
Investment, Identifier [Axis]: Affordable Care Inc, Health Care Equipment & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 4.50% [6],[19],[43] 4.50% [6],[19],[43] 4.50% [6],[19],[43] 4.50% [6],[19],[43] 4.50% [6],[19],[43] 4.50% [6],[19],[43] 4.50% [6],[19],[43] 5.50% [8],[11],[44] 5.50% [8],[11],[44] 5.50% [8],[11],[44] 5.50% [8],[11],[44] 5.50% [8],[11],[44] 5.50% [8],[11],[44] 5.50% [8],[11],[44]  
Rate, PIK 0.00% [6],[19],[43] 0.00% [6],[19],[43] 0.00% [6],[19],[43] 0.00% [6],[19],[43] 0.00% [6],[19],[43] 0.00% [6],[19],[43] 0.00% [6],[19],[43] 0.00% [8],[11],[44] 0.00% [8],[11],[44] 0.00% [8],[11],[44] 0.00% [8],[11],[44] 0.00% [8],[11],[44] 0.00% [8],[11],[44] 0.00% [8],[11],[44]  
Rate, Max PIK 1.30% [6],[19],[43] 1.30% [6],[19],[43] 1.30% [6],[19],[43] 1.30% [6],[19],[43] 1.30% [6],[19],[43] 1.30% [6],[19],[43] 1.30% [6],[19],[43] 1.30% [8],[11],[44] 1.30% [8],[11],[44] 1.30% [8],[11],[44] 1.30% [8],[11],[44] 1.30% [8],[11],[44] 1.30% [8],[11],[44] 1.30% [8],[11],[44]  
Base Rate Floor 0.80% [6],[19],[43] 0.80% [6],[19],[43] 0.80% [6],[19],[43] 0.80% [6],[19],[43] 0.80% [6],[19],[43] 0.80% [6],[19],[43] 0.80% [6],[19],[43] 0.80% [11],[44] 0.80% [11],[44] 0.80% [11],[44] 0.80% [11],[44] 0.80% [11],[44] 0.80% [11],[44] 0.80% [11],[44]  
Principal amount $ 12,800,000 [13],[19],[43]             $ 1,400,000 [11],[14],[44]              
Amortized Cost 12,800,000 [19],[43]             1,400,000 [11],[44]              
Fair Value $ (12,700,000) [4],[19],[43]             $ (1,400,000) [1],[11],[44]              
Investment, Identifier [Axis]: Affordable Care Inc, Health Care Equipment & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 4.50% [6],[19],[43] 4.50% [6],[19],[43] 4.50% [6],[19],[43] 4.50% [6],[19],[43] 4.50% [6],[19],[43] 4.50% [6],[19],[43] 4.50% [6],[19],[43] 5.50% [8],[18],[44] 5.50% [8],[18],[44] 5.50% [8],[18],[44] 5.50% [8],[18],[44] 5.50% [8],[18],[44] 5.50% [8],[18],[44] 5.50% [8],[18],[44]  
Rate, PIK 1.30% [6],[19],[43] 1.30% [6],[19],[43] 1.30% [6],[19],[43] 1.30% [6],[19],[43] 1.30% [6],[19],[43] 1.30% [6],[19],[43] 1.30% [6],[19],[43] 0.00% [8],[18],[44] 0.00% [8],[18],[44] 0.00% [8],[18],[44] 0.00% [8],[18],[44] 0.00% [8],[18],[44] 0.00% [8],[18],[44] 0.00% [8],[18],[44]  
Rate, Max PIK 1.30% [6],[19],[43] 1.30% [6],[19],[43] 1.30% [6],[19],[43] 1.30% [6],[19],[43] 1.30% [6],[19],[43] 1.30% [6],[19],[43] 1.30% [6],[19],[43] 1.30% [8],[18],[44] 1.30% [8],[18],[44] 1.30% [8],[18],[44] 1.30% [8],[18],[44] 1.30% [8],[18],[44] 1.30% [8],[18],[44] 1.30% [8],[18],[44]  
Base Rate Floor 0.80% [6],[19],[43] 0.80% [6],[19],[43] 0.80% [6],[19],[43] 0.80% [6],[19],[43] 0.80% [6],[19],[43] 0.80% [6],[19],[43] 0.80% [6],[19],[43] 0.80% [18],[44] 0.80% [18],[44] 0.80% [18],[44] 0.80% [18],[44] 0.80% [18],[44] 0.80% [18],[44] 0.80% [18],[44]  
Principal amount $ 25,700,000 [13],[19],[43]             $ 28,400,000 [14],[18],[44]              
Amortized Cost 25,700,000 [19],[43]             28,400,000 [18],[44]              
Fair Value (25,300,000) [4],[19],[43]             $ (27,800,000) [1],[18],[44]              
Investment, Identifier [Axis]: Affordable Care Inc, Health Care Equipment & Services 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[18],[44]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Rate, PIK [8],[18],[44]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Rate, Max PIK [8],[18],[44]               1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30%  
Base Rate Floor [18],[44]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [14],[18],[44]               $ 11,400,000              
Amortized Cost [18],[44]               11,400,000              
Fair Value [1],[18],[44]               (11,200,000)              
Investment, Identifier [Axis]: Affordable Care Inc, Preferred Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (49,100,000)             $ (49,900,000)              
Investment, Identifier [Axis]: Affordable Care Inc, Preferred Stock, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 11.80% [6],[7],[43] 11.80% [6],[7],[43] 11.80% [6],[7],[43] 11.80% [6],[7],[43] 11.80% [6],[7],[43] 11.80% [6],[7],[43] 11.80% [6],[7],[43] 11.80% [8],[11],[44] 11.80% [8],[11],[44] 11.80% [8],[11],[44] 11.80% [8],[11],[44] 11.80% [8],[11],[44] 11.80% [8],[11],[44] 11.80% [8],[11],[44]  
Rate, Max PIK 11.80% [6],[7],[43] 11.80% [6],[7],[43] 11.80% [6],[7],[43] 11.80% [6],[7],[43] 11.80% [6],[7],[43] 11.80% [6],[7],[43] 11.80% [6],[7],[43] 11.80% [8],[11],[44] 11.80% [8],[11],[44] 11.80% [8],[11],[44] 11.80% [8],[11],[44] 11.80% [8],[11],[44] 11.80% [8],[11],[44] 11.80% [8],[11],[44]  
Number of Shares | shares 49,073,000 [7],[43] 49,073,000 [7],[43] 49,073,000 [7],[43] 49,073,000 [7],[43] 49,073,000 [7],[43] 49,073,000 [7],[43] 49,073,000 [7],[43] 49,073,000 [11],[44] 49,073,000 [11],[44] 49,073,000 [11],[44] 49,073,000 [11],[44] 49,073,000 [11],[44] 49,073,000 [11],[44] 49,073,000 [11],[44]  
Amortized Cost $ 48,100,000 [7],[43]             $ 48,100,000 [11],[44]              
Fair Value $ (49,100,000) [4],[7],[43]             (49,900,000) [1],[11],[44]              
Investment, Identifier [Axis]: Affordable Care Inc, Senior Secured Loans—First Lien -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               0             0
Investment, Identifier [Axis]: Affordable Care Inc, Senior Secured Loans—First Lien -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ (53,100,000)             (59,900,000)
Investment, Identifier [Axis]: Alacrity Solutions Group LLC, Insurance | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 40,400,000             $ 40,600,000              
Amortized Cost 39,700,000             39,900,000              
Fair Value $ (39,200,000)             $ (39,100,000)              
Investment, Identifier [Axis]: Alacrity Solutions Group LLC, Insurance 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [8],[11] 5.25% [8],[11] 5.25% [8],[11] 5.25% [8],[11] 5.25% [8],[11] 5.25% [8],[11] 5.25% [8],[11]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 4,900,000 [7],[13]             $ 28,400,000 [11],[14]              
Amortized Cost 4,700,000 [7]             28,000,000.0 [11]              
Fair Value $ (4,700,000) [4],[7]             $ (27,300,000) [1],[11]              
Investment, Identifier [Axis]: Alacrity Solutions Group LLC, Insurance 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% [6],[7],[41] 5.25% [6],[7],[41] 5.25% [6],[7],[41] 5.25% [6],[7],[41] 5.25% [6],[7],[41] 5.25% [6],[7],[41] 5.25% [6],[7],[41] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18]  
Base Rate Floor 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 28,300,000 [7],[13],[41]             $ 10,800,000 [14],[18]              
Amortized Cost 27,900,000 [7],[41]             10,600,000 [18]              
Fair Value $ (27,400,000) [4],[7],[41]             $ (10,400,000) [1],[18]              
Investment, Identifier [Axis]: Alacrity Solutions Group LLC, Insurance 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19] 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%                
Base Rate Floor [6],[19] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[19] $ 5,900,000                            
Amortized Cost [19] 5,900,000                            
Fair Value [4],[19] $ (5,700,000)                            
Investment, Identifier [Axis]: Alera Group Intermediate Holdings Inc, Insurance | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 32,200,000             $ 32,300,000              
Amortized Cost 31,800,000             31,900,000              
Fair Value $ (31,200,000)             $ (30,700,000)              
Investment, Identifier [Axis]: Alera Group Intermediate Holdings Inc, Insurance 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[41] 6.00% [6],[41] 6.00% [6],[41] 6.00% [6],[41] 6.00% [6],[41] 6.00% [6],[41] 6.00% [6],[41] 6.00% [8],[42] 6.00% [8],[42] 6.00% [8],[42] 6.00% [8],[42] 6.00% [8],[42] 6.00% [8],[42] 6.00% [8],[42]  
Base Rate Floor 0.80% [6],[41] 0.80% [6],[41] 0.80% [6],[41] 0.80% [6],[41] 0.80% [6],[41] 0.80% [6],[41] 0.80% [6],[41] 0.80% [42] 0.80% [42] 0.80% [42] 0.80% [42] 0.80% [42] 0.80% [42] 0.80% [42]  
Principal amount $ 9,100,000 [13],[41]             $ 9,200,000 [14],[42]              
Amortized Cost 9,100,000 [41]             9,100,000 [42]              
Fair Value $ (8,900,000) [4],[41]             $ (8,700,000) [1],[42]              
Investment, Identifier [Axis]: Alera Group Intermediate Holdings Inc, Insurance 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[7],[41] 6.00% [6],[7],[41] 6.00% [6],[7],[41] 6.00% [6],[7],[41] 6.00% [6],[7],[41] 6.00% [6],[7],[41] 6.00% [6],[7],[41] 6.00% [8],[11],[42] 6.00% [8],[11],[42] 6.00% [8],[11],[42] 6.00% [8],[11],[42] 6.00% [8],[11],[42] 6.00% [8],[11],[42] 6.00% [8],[11],[42]  
Base Rate Floor 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [11],[42] 0.80% [11],[42] 0.80% [11],[42] 0.80% [11],[42] 0.80% [11],[42] 0.80% [11],[42] 0.80% [11],[42]  
Principal amount $ 22,500,000 [7],[13],[41]             $ 22,500,000 [11],[14],[42]              
Amortized Cost 22,500,000 [7],[41]             22,500,000 [11],[42]              
Fair Value $ (21,800,000) [4],[7],[41]             $ (21,400,000) [1],[11],[42]              
Investment, Identifier [Axis]: Alstom SA, Transportation | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Rate, PIK 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%  
Rate, Max PIK 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 6,300,000             $ 6,200,000              
Amortized Cost 5,900,000             5,800,000              
Fair Value $ (3,000,000.0)             $ (3,500,000)              
Investment, Identifier [Axis]: Altavair AirFinance, Private Equity, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 130,473,039 [7],[13],[33] 130,473,039 [7],[13],[33] 130,473,039 [7],[13],[33] 130,473,039 [7],[13],[33] 130,473,039 [7],[13],[33] 130,473,039 [7],[13],[33] 130,473,039 [7],[13],[33] 140,212,883 [11],[14],[28] 140,212,883 [11],[14],[28] 140,212,883 [11],[14],[28] 140,212,883 [11],[14],[28] 140,212,883 [11],[14],[28] 140,212,883 [11],[14],[28] 140,212,883 [11],[14],[28]  
Amortized Cost $ 131,400,000 [7],[33]             $ 141,100,000 [11],[28]              
Fair Value $ (144,200,000) [4],[7],[33]             $ (162,100,000) [1],[11],[28]              
Investment, Identifier [Axis]: Altavair AirFinance, Private Equity, Capital Goods | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 33,964,539 33,964,539 33,964,539 33,964,539 33,964,539 33,964,539 33,964,539 36,500,000 36,500,000 36,500,000 36,500,000 36,500,000 36,500,000 36,500,000  
Amortized Cost $ 40,000,000.0             $ 43,000,000.0              
Fair Value $ (37,500,000)             $ (42,200,000)              
Investment, Identifier [Axis]: American Airlines Group Inc, Transportation | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate               1.75% 1.75% 1.75% 1.75% 1.75% 1.75% 1.75%  
Base Rate Floor               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount               $ 2,500,000              
Amortized Cost               2,300,000              
Fair Value               $ (2,400,000)              
Investment, Identifier [Axis]: American Vision Partners, Health Care Equipment & Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 19,500,000             $ 19,500,000              
Amortized Cost 19,300,000             19,300,000              
Fair Value $ (18,800,000)             $ (18,900,000)              
Investment, Identifier [Axis]: American Vision Partners, Health Care Equipment & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [8],[11],[12] 5.75% [8],[11],[12] 5.75% [8],[11],[12] 5.75% [8],[11],[12] 5.75% [8],[11],[12] 5.75% [8],[11],[12] 5.75% [8],[11],[12]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [11],[12] 0.80% [11],[12] 0.80% [11],[12] 0.80% [11],[12] 0.80% [11],[12] 0.80% [11],[12] 0.80% [11],[12]  
Principal amount $ 3,100,000 [7],[13]             $ 113,000,000.0 [11],[12],[14]              
Amortized Cost 3,100,000 [7]             112,500,000 [11],[12]              
Fair Value $ (3,000,000.0) [4],[7]             $ (109,100,000) [1],[11],[12]              
Investment, Identifier [Axis]: American Vision Partners, Health Care Equipment & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[7],[15] 5.75% [6],[7],[15] 5.75% [6],[7],[15] 5.75% [6],[7],[15] 5.75% [6],[7],[15] 5.75% [6],[7],[15] 5.75% [6],[7],[15] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18]  
Base Rate Floor 0.80% [6],[7],[15] 0.80% [6],[7],[15] 0.80% [6],[7],[15] 0.80% [6],[7],[15] 0.80% [6],[7],[15] 0.80% [6],[7],[15] 0.80% [6],[7],[15] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 74,100,000 [7],[13],[15]             $ 7,800,000 [14],[18]              
Amortized Cost 73,500,000 [7],[15]             7,800,000 [18]              
Fair Value $ (71,500,000) [4],[7],[15]             $ (7,500,000) [1],[18]              
Investment, Identifier [Axis]: American Vision Partners, Health Care Equipment & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base Rate Floor [6],[7] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [7],[13] $ 38,600,000                            
Amortized Cost [7] 38,600,000                            
Fair Value [4],[7] $ (37,300,000)                            
Investment, Identifier [Axis]: American Vision Partners, Health Care Equipment & Services 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base Rate Floor [6],[19] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[19] $ 4,700,000                            
Amortized Cost [19] 4,700,000                            
Fair Value [4],[19] $ (4,500,000)                            
Investment, Identifier [Axis]: American Vision Partners, Private Equity, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 2,655,491 [7],[32] 2,655,491 [7],[32] 2,655,491 [7],[32] 2,655,491 [7],[32] 2,655,491 [7],[32] 2,655,491 [7],[32] 2,655,491 [7],[32] 2,655,491 [11],[27] 2,655,491 [11],[27] 2,655,491 [11],[27] 2,655,491 [11],[27] 2,655,491 [11],[27] 2,655,491 [11],[27] 2,655,491 [11],[27]  
Amortized Cost $ 2,700,000 [7],[32]             $ 2,700,000 [11],[27]              
Fair Value $ (2,200,000) [4],[7],[32]             $ (2,200,000) [1],[11],[27]              
Investment, Identifier [Axis]: Amerivet Partners Management Inc, Health Care Equipment & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 113,600,000 [7],[13]             $ 95,400,000 [11],[14]              
Amortized Cost 112,700,000 [7]             94,500,000 [11]              
Fair Value $ (109,500,000) [4],[7]             $ (91,800,000) [1],[11]              
Investment, Identifier [Axis]: Amerivet Partners Management Inc, Health Care Equipment & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 8,400,000 [13],[19]             $ 17,200,000 [11],[14]              
Amortized Cost 8,400,000 [19]             17,200,000 [11]              
Fair Value $ (8,100,000) [4],[19]             $ (16,600,000) [1],[11]              
Investment, Identifier [Axis]: Amerivet Partners Management Inc, Health Care Equipment & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 48,800,000 [13],[19]             $ 8,400,000 [14],[18]              
Amortized Cost 48,800,000 [19]             8,400,000 [18]              
Fair Value $ (47,000,000.0) [4],[19]             $ (8,100,000) [1],[18]              
Investment, Identifier [Axis]: Amerivet Partners Management Inc, Health Care Equipment & Services 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[18]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base Rate Floor [18]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [14],[18]               $ 50,100,000              
Amortized Cost [18]               50,100,000              
Fair Value [1],[18]               $ (48,200,000)              
Investment, Identifier [Axis]: Amerivet Partners Management Inc, Preferred Stock, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 11.50% [6],[7] 11.50% [6],[7] 11.50% [6],[7] 11.50% [6],[7] 11.50% [6],[7] 11.50% [6],[7] 11.50% [6],[7] 11.50% [8],[11] 11.50% [8],[11] 11.50% [8],[11] 11.50% [8],[11] 11.50% [8],[11] 11.50% [8],[11] 11.50% [8],[11]  
Rate, Max PIK 11.50% [6],[7] 11.50% [6],[7] 11.50% [6],[7] 11.50% [6],[7] 11.50% [6],[7] 11.50% [6],[7] 11.50% [6],[7] 11.50% [8],[11] 11.50% [8],[11] 11.50% [8],[11] 11.50% [8],[11] 11.50% [8],[11] 11.50% [8],[11] 11.50% [8],[11]  
Number of Shares | shares 12,702,290 [7] 12,702,290 [7] 12,702,290 [7] 12,702,290 [7] 12,702,290 [7] 12,702,290 [7] 12,702,290 [7] 12,702,290 [11] 12,702,290 [11] 12,702,290 [11] 12,702,290 [11] 12,702,290 [11] 12,702,290 [11] 12,702,290 [11]  
Amortized Cost $ 12,300,000 [7]             $ 12,300,000 [11]              
Fair Value $ (11,700,000) [4],[7]             $ (11,800,000) [1],[11]              
Investment, Identifier [Axis]: Ammeraal Beltech Holding BV, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.75% [6],[7],[20],[33],[36] 7.75% [6],[7],[20],[33],[36] 7.75% [6],[7],[20],[33],[36] 7.75% [6],[7],[20],[33],[36] 7.75% [6],[7],[20],[33],[36] 7.75% [6],[7],[20],[33],[36] 7.75% [6],[7],[20],[33],[36] 7.75% [8],[11],[22],[28],[37] 7.75% [8],[11],[22],[28],[37] 7.75% [8],[11],[22],[28],[37] 7.75% [8],[11],[22],[28],[37] 7.75% [8],[11],[22],[28],[37] 7.75% [8],[11],[22],[28],[37] 7.75% [8],[11],[22],[28],[37]  
Base Rate Floor [6],[7],[20],[33],[36] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount $ 23,600,000 [7],[13],[20],[33],[36]             $ 23,600,000 [11],[14],[22],[28],[37]              
Amortized Cost 21,900,000 [7],[20],[33],[36]             21,800,000 [11],[22],[28],[37]              
Fair Value $ (23,600,000) [4],[7],[20],[33],[36]             $ (23,000,000.0) [1],[11],[22],[28],[37]              
Investment, Identifier [Axis]: Ammeraal Beltech Holding BV, Capital Goods 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | €       € 4.8             € 4.8        
Amortized Cost $ 4,900,000             $ 4,800,000              
Fair Value $ (5,000,000.0)             $ (4,800,000)              
Investment, Identifier [Axis]: Ammeraal Beltech Holding BV, Capital Goods 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount $ 42,800,000             $ 42,800,000              
Amortized Cost 42,100,000             42,100,000              
Fair Value (42,800,000)             (41,800,000)              
Investment, Identifier [Axis]: Amtek Global Technology Pte Ltd 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               (3,900,000)             (34,800,000)
Investment, Identifier [Axis]: Amtek Global Technology Pte Ltd 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               0             0
Investment, Identifier [Axis]: Amtek Global Technology Pte Ltd, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ 0             $ 0             0
Investment, Identifier [Axis]: Amtek Global Technology Pte Ltd, Common Stock, Automobiles & Components                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 7,046,126 [7],[32],[33],[34],[45] 7,046,126 [7],[32],[33],[34],[45] 7,046,126 [7],[32],[33],[34],[45] 7,046,126 [7],[32],[33],[34],[45] 7,046,126 [7],[32],[33],[34],[45] 7,046,126 [7],[32],[33],[34],[45] 7,046,126 [7],[32],[33],[34],[45] 7,046,126 [11],[27],[28],[35],[46] 7,046,126 [11],[27],[28],[35],[46] 7,046,126 [11],[27],[28],[35],[46] 7,046,126 [11],[27],[28],[35],[46] 7,046,126 [11],[27],[28],[35],[46] 7,046,126 [11],[27],[28],[35],[46] 7,046,126 [11],[27],[28],[35],[46]  
Amortized Cost $ 0 [7],[32],[33],[34],[45]             $ 0 [11],[27],[28],[35],[46]              
Fair Value 0 [4],[7],[32],[33],[34],[45]             0 [1],[11],[27],[28],[35],[46]              
Investment, Identifier [Axis]: Amtek Global Technology Pte Ltd, Ordinary Shares                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ 0             $ 0             0
Investment, Identifier [Axis]: Amtek Global Technology Pte Ltd, Ordinary Shares, Automobiles & Components                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 5,735,804,056 [7],[32],[33],[34] 5,735,804,056 [7],[32],[33],[34] 5,735,804,056 [7],[32],[33],[34] 5,735,804,056 [7],[32],[33],[34] 5,735,804,056 [7],[32],[33],[34] 5,735,804,056 [7],[32],[33],[34] 5,735,804,056 [7],[32],[33],[34] 5,735,804,056 [11],[27],[28],[35] 5,735,804,056 [11],[27],[28],[35] 5,735,804,056 [11],[27],[28],[35] 5,735,804,056 [11],[27],[28],[35] 5,735,804,056 [11],[27],[28],[35] 5,735,804,056 [11],[27],[28],[35] 5,735,804,056 [11],[27],[28],[35]  
Amortized Cost $ 30,700,000 [7],[32],[33],[34]             $ 30,700,000 [11],[27],[28],[35]              
Fair Value 0 [4],[7],[32],[33],[34]             0 [1],[11],[27],[28],[35]              
Investment, Identifier [Axis]: Amtek Global Technology Pte Ltd, Private Equity                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ 0             $ 0             0
Investment, Identifier [Axis]: Amtek Global Technology Pte Ltd, Private Equity, Automobiles & Components                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 4,097 [7],[32],[33],[34] 4,097 [7],[32],[33],[34] 4,097 [7],[32],[33],[34] 4,097 [7],[32],[33],[34] 4,097 [7],[32],[33],[34] 4,097 [7],[32],[33],[34] 4,097 [7],[32],[33],[34] 4,097 [11],[27],[28],[35] 4,097 [11],[27],[28],[35] 4,097 [11],[27],[28],[35] 4,097 [11],[27],[28],[35] 4,097 [11],[27],[28],[35] 4,097 [11],[27],[28],[35] 4,097 [11],[27],[28],[35]  
Amortized Cost $ 0 [7],[32],[33],[34]             $ 0 [11],[27],[28],[35]              
Fair Value $ 0 [4],[7],[32],[33],[34]             $ 0 [1],[11],[27],[28],[35]              
Investment, Identifier [Axis]: Angelica Corp, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 10.00% [6],[29],[32],[47] 10.00% [6],[29],[32],[47] 10.00% [6],[29],[32],[47] 10.00% [6],[29],[32],[47] 10.00% [6],[29],[32],[47] 10.00% [6],[29],[32],[47] 10.00% [6],[29],[32],[47] 10.00% [8],[24],[27],[48] 10.00% [8],[24],[27],[48] 10.00% [8],[24],[27],[48] 10.00% [8],[24],[27],[48] 10.00% [8],[24],[27],[48] 10.00% [8],[24],[27],[48] 10.00% [8],[24],[27],[48]  
Rate, Max PIK 10.00% [6],[29],[32],[47] 10.00% [6],[29],[32],[47] 10.00% [6],[29],[32],[47] 10.00% [6],[29],[32],[47] 10.00% [6],[29],[32],[47] 10.00% [6],[29],[32],[47] 10.00% [6],[29],[32],[47] 10.00% [8],[24],[27],[48] 10.00% [8],[24],[27],[48] 10.00% [8],[24],[27],[48] 10.00% [8],[24],[27],[48] 10.00% [8],[24],[27],[48] 10.00% [8],[24],[27],[48] 10.00% [8],[24],[27],[48]  
Principal amount $ 59,000,000.0 [13],[29],[32],[47]             $ 59,000,000.0 [14],[24],[27],[48]              
Amortized Cost 42,300,000 [29],[32],[47]             42,300,000 [24],[27],[48]              
Fair Value $ (900,000) [4],[29],[32],[47]             $ (900,000) [1],[24],[27],[48]              
Investment, Identifier [Axis]: Angelica Corp, Limited Partnership Interest, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [27],[48]               877,044 877,044 877,044 877,044 877,044 877,044 877,044  
Amortized Cost [27],[48]               $ 47,600,000              
Fair Value [1],[27],[48]               $ 0              
Investment, Identifier [Axis]: Apex Group Limited, Diversified Financials 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11],[28],[40]               3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75%  
Base Rate Floor [11],[28],[40]               0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount [11],[14],[28],[40]               $ 2,500,000              
Amortized Cost [11],[28],[40]               2,500,000              
Fair Value [1],[11],[28],[40]               $ (2,400,000)              
Investment, Identifier [Axis]: Apex Group Limited, Diversified Financials 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate               3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75%  
Base Rate Floor               0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount               $ 4,200,000              
Amortized Cost               4,200,000              
Fair Value               $ (4,000,000.0)              
Investment, Identifier [Axis]: Apex Group Limited, Diversified Financials 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11],[28],[40]               4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00%  
Base Rate Floor [11],[28],[40]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | € [11],[14],[28],[40]                     € 2.0        
Amortized Cost [11],[28],[40]               $ 2,300,000              
Fair Value [1],[11],[28],[40]               $ (2,000,000.0)              
Investment, Identifier [Axis]: Apex Group Limited, Diversified Financials 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate               4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00%  
Base Rate Floor               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | €                     € 1.6        
Amortized Cost               $ 1,900,000              
Fair Value               $ (1,600,000)              
Investment, Identifier [Axis]: Apex Group Limited, Diversified Financials 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11],[28]               6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%  
Base Rate Floor [11],[28]               0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount [11],[14],[28]               $ 55,000,000.0              
Amortized Cost [11],[28]               54,000,000.0              
Fair Value [1],[11],[28]               $ (51,700,000)              
Investment, Identifier [Axis]: Apex Group Limited, Diversified Financials 3 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate               6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%  
Base Rate Floor               0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount               $ 40,000,000.0              
Amortized Cost               39,700,000              
Fair Value               $ (37,600,000)              
Investment, Identifier [Axis]: Apex Group Limited, Financial Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[33],[39],[41] 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75%                
Base Rate Floor [6],[33],[39],[41] 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount [13],[33],[39],[41] $ 2,500,000                            
Amortized Cost [33],[39],[41] 2,500,000                            
Fair Value [4],[33],[39],[41] $ (2,400,000)                            
Investment, Identifier [Axis]: Apex Group Limited, Financial Services 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75%                
Base Rate Floor 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount $ 4,200,000                            
Amortized Cost 4,200,000                            
Fair Value $ (4,100,000)                            
Investment, Identifier [Axis]: Apex Group Limited, Financial Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[33],[39] 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00%                
Base Rate Floor [6],[7],[33],[39] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | € [7],[13],[33],[39]       € 2.0                      
Amortized Cost [7],[33],[39] $ 2,300,000                            
Fair Value [4],[7],[33],[39] $ (2,100,000)                            
Investment, Identifier [Axis]: Apex Group Limited, Financial Services 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00%                
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | €       € 1.6                      
Amortized Cost $ 1,900,000                            
Fair Value $ (1,700,000)                            
Investment, Identifier [Axis]: Apex Group Limited, Financial Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[33] 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%                
Base Rate Floor [6],[7],[33] 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount [7],[13],[33] $ 55,000,000.0                            
Amortized Cost [7],[33] 54,000,000.0                            
Fair Value [4],[7],[33] $ (53,300,000)                            
Investment, Identifier [Axis]: Apex Group Limited, Financial Services 3 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%                
Base Rate Floor 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount $ 40,000,000.0                            
Amortized Cost 39,700,000                            
Fair Value $ (38,800,000)                            
Investment, Identifier [Axis]: Arcfield Acquisition Corp, Capital Goods | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 8,000,000.0             $ 8,000,000.0              
Amortized Cost 8,000,000.0             8,000,000.0              
Fair Value $ (7,900,000)             $ (7,900,000)              
Investment, Identifier [Axis]: Arcfield Acquisition Corp, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[15],[21] 5.75% [6],[15],[21] 5.75% [6],[15],[21] 5.75% [6],[15],[21] 5.75% [6],[15],[21] 5.75% [6],[15],[21] 5.75% [6],[15],[21] 5.75% [8],[12],[23] 5.75% [8],[12],[23] 5.75% [8],[12],[23] 5.75% [8],[12],[23] 5.75% [8],[12],[23] 5.75% [8],[12],[23] 5.75% [8],[12],[23]  
Base Rate Floor 0.80% [6],[15],[21] 0.80% [6],[15],[21] 0.80% [6],[15],[21] 0.80% [6],[15],[21] 0.80% [6],[15],[21] 0.80% [6],[15],[21] 0.80% [6],[15],[21] 0.80% [12],[23] 0.80% [12],[23] 0.80% [12],[23] 0.80% [12],[23] 0.80% [12],[23] 0.80% [12],[23] 0.80% [12],[23]  
Principal amount $ 40,200,000 [13],[15],[21]             $ 40,300,000 [12],[14],[23]              
Amortized Cost 39,900,000 [15],[21]             39,900,000 [12],[23]              
Fair Value $ (39,600,000) [4],[15],[21]             $ (39,400,000) [1],[12],[23]              
Investment, Identifier [Axis]: Arcfield Acquisition Corp, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 7,100,000 [13],[19]             $ 7,100,000 [14],[18]              
Amortized Cost 7,100,000 [19]             7,100,000 [18]              
Fair Value $ (7,000,000.0) [4],[19]             $ (6,900,000) [1],[18]              
Investment, Identifier [Axis]: Arcos LLC/VA, Preferred Stock, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 9.50% [6],[7] 9.50% [6],[7] 9.50% [6],[7] 9.50% [6],[7] 9.50% [6],[7] 9.50% [6],[7] 9.50% [6],[7] 9.50% [8],[11] 9.50% [8],[11] 9.50% [8],[11] 9.50% [8],[11] 9.50% [8],[11] 9.50% [8],[11] 9.50% [8],[11]  
Rate, Max PIK 9.50% [6],[7] 9.50% [6],[7] 9.50% [6],[7] 9.50% [6],[7] 9.50% [6],[7] 9.50% [6],[7] 9.50% [6],[7] 9.50% [8],[11] 9.50% [8],[11] 9.50% [8],[11] 9.50% [8],[11] 9.50% [8],[11] 9.50% [8],[11] 9.50% [8],[11]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Number of Shares | shares 15,000,000 [7] 15,000,000 [7] 15,000,000 [7] 15,000,000 [7] 15,000,000 [7] 15,000,000 [7] 15,000,000 [7] 15,000,000 [11] 15,000,000 [11] 15,000,000 [11] 15,000,000 [11] 15,000,000 [11] 15,000,000 [11] 15,000,000 [11]  
Amortized Cost $ 14,000,000.0 [7]             $ 14,000,000.0 [11]              
Fair Value $ (13,100,000) [4],[7]             $ (13,400,000) [1],[11]              
Investment, Identifier [Axis]: Arcos LLC/VA, Software & Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 22,200,000             $ 22,200,000              
Amortized Cost 22,000,000.0             22,000,000.0              
Fair Value $ (20,300,000)             $ (20,600,000)              
Investment, Identifier [Axis]: Arcos LLC/VA, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[41] 5.75% [6],[41] 5.75% [6],[41] 5.75% [6],[41] 5.75% [6],[41] 5.75% [6],[41] 5.75% [6],[41] 5.75% [8],[42] 5.75% [8],[42] 5.75% [8],[42] 5.75% [8],[42] 5.75% [8],[42] 5.75% [8],[42] 5.75% [8],[42]  
Base Rate Floor 1.00% [6],[41] 1.00% [6],[41] 1.00% [6],[41] 1.00% [6],[41] 1.00% [6],[41] 1.00% [6],[41] 1.00% [6],[41] 1.00% [42] 1.00% [42] 1.00% [42] 1.00% [42] 1.00% [42] 1.00% [42] 1.00% [42]  
Principal amount $ 12,300,000 [13],[41]             $ 12,300,000 [14],[42]              
Amortized Cost 12,100,000 [41]             12,200,000 [42]              
Fair Value $ (11,300,000) [4],[41]             $ (11,400,000) [1],[42]              
Investment, Identifier [Axis]: Arcos LLC/VA, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 4,500,000 [13],[19]             $ 4,500,000 [14],[18]              
Amortized Cost 4,500,000 [19]             4,500,000 [18]              
Fair Value $ (4,100,000) [4],[19]             $ (4,200,000) [1],[18]              
Investment, Identifier [Axis]: Ardonagh Group Ltd, Insurance 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.25% [6],[7],[33] 7.25% [6],[7],[33] 7.25% [6],[7],[33] 7.25% [6],[7],[33] 7.25% [6],[7],[33] 7.25% [6],[7],[33] 7.25% [6],[7],[33] 7.00% [8],[11],[28] 7.00% [8],[11],[28] 7.00% [8],[11],[28] 7.00% [8],[11],[28] 7.00% [8],[11],[28] 7.00% [8],[11],[28] 7.00% [8],[11],[28]  
Base Rate Floor 0.80% [6],[7],[33] 0.80% [6],[7],[33] 0.80% [6],[7],[33] 0.80% [6],[7],[33] 0.80% [6],[7],[33] 0.80% [6],[7],[33] 0.80% [6],[7],[33] 0.80% [11],[28] 0.80% [11],[28] 0.80% [11],[28] 0.80% [11],[28] 0.80% [11],[28] 0.80% [11],[28] 0.80% [11],[28]  
Principal amount | £         £ 0.8 [7],[13],[33]             £ 0.8 [11],[14],[28]      
Amortized Cost $ 1,000,000.0 [7],[33]             $ 1,000,000.0 [11],[28]              
Fair Value $ (1,000,000.0) [4],[7],[33]             $ (900,000) [1],[11],[28]              
Investment, Identifier [Axis]: Ardonagh Group Ltd, Insurance 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount | £         £ 3.8             £ 3.8      
Amortized Cost $ 4,700,000             $ 4,700,000              
Fair Value $ (4,600,000)             $ (4,500,000)              
Investment, Identifier [Axis]: Ardonagh Group Ltd, Insurance 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.25% [6],[7],[33] 7.25% [6],[7],[33] 7.25% [6],[7],[33] 7.25% [6],[7],[33] 7.25% [6],[7],[33] 7.25% [6],[7],[33] 7.25% [6],[7],[33] 7.00% [8],[11],[28] 7.00% [8],[11],[28] 7.00% [8],[11],[28] 7.00% [8],[11],[28] 7.00% [8],[11],[28] 7.00% [8],[11],[28] 7.00% [8],[11],[28]  
Base Rate Floor 1.00% [6],[7],[33] 1.00% [6],[7],[33] 1.00% [6],[7],[33] 1.00% [6],[7],[33] 1.00% [6],[7],[33] 1.00% [6],[7],[33] 1.00% [6],[7],[33] 1.00% [11],[28] 1.00% [11],[28] 1.00% [11],[28] 1.00% [11],[28] 1.00% [11],[28] 1.00% [11],[28] 1.00% [11],[28]  
Principal amount | €       € 19.0 [7],[13],[33]             € 19.0 [11],[14],[28]        
Amortized Cost $ 19,300,000 [7],[33]             $ 19,300,000 [11],[28]              
Fair Value $ (20,300,000) [4],[7],[33]             $ (20,200,000) [1],[11],[28]              
Investment, Identifier [Axis]: Ardonagh Group Ltd, Insurance 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount | €       € 0.5             € 0.5        
Amortized Cost $ 500,000             $ 500,000              
Fair Value $ (500,000)             $ (500,000)              
Investment, Identifier [Axis]: Ardonagh Group Ltd, Insurance 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[33] 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%                
Rate, PIK [8],[11],[28],[40]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Rate, Max PIK [8],[11],[28],[40]               12.80% 12.80% 12.80% 12.80% 12.80% 12.80% 12.80%  
Rate, Stated interest rate [8],[11],[28],[40]               11.50% 11.50% 11.50% 11.50% 11.50% 11.50% 11.50%  
Base Rate Floor [6],[7],[33] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount $ 9,900,000 [7],[13],[33]             $ 1,000,000.0 [11],[14],[28],[40]              
Amortized Cost 9,300,000 [7],[33]             1,000,000.0 [11],[28],[40]              
Fair Value $ (9,700,000) [4],[7],[33]             $ (900,000) [1],[11],[28],[40]              
Investment, Identifier [Axis]: Ardonagh Group Ltd, Insurance 3 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 54,800,000             $ 54,800,000              
Amortized Cost 54,300,000             54,300,000              
Fair Value $ (52,700,000)             $ (53,100,000)              
Investment, Identifier [Axis]: Ardonagh Group Ltd, Insurance 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19],[33] 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%                
Base Rate Floor [6],[19],[33] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[19],[33] $ 9,900,000                            
Amortized Cost [19],[33] 9,900,000                            
Fair Value [4],[19],[33] $ (9,700,000)                            
Investment, Identifier [Axis]: Ardonagh Group Ltd, Insurance 5                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [7],[33],[39] 11.50% 11.50% 11.50% 11.50% 11.50% 11.50% 11.50%                
Rate, PIK [7],[33],[39] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Rate, Max PIK [7],[33],[39] 12.80% 12.80% 12.80% 12.80% 12.80% 12.80% 12.80%                
Principal amount [7],[33],[39] $ 1,000,000.0                            
Amortized Cost [7],[33],[39] 1,000,000.0                            
Fair Value [7],[33],[39] $ (900,000)                            
Investment, Identifier [Axis]: Arena Energy LP, Warrants, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 68,186,525 [7] 68,186,525 [7] 68,186,525 [7] 68,186,525 [7] 68,186,525 [7] 68,186,525 [7] 68,186,525 [7] 68,186,525 [11] 68,186,525 [11] 68,186,525 [11] 68,186,525 [11] 68,186,525 [11] 68,186,525 [11] 68,186,525 [11]  
Amortized Cost $ 400,000 [7]             $ 400,000 [11]              
Fair Value $ (300,000) [4],[7]             $ (500,000) [1],[11]              
Investment, Identifier [Axis]: Arrotex Australia Group Pty Ltd, Pharmaceuticals, Biotechnology & Life Sciences 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% [6],[7],[33] 5.25% [6],[7],[33] 5.25% [6],[7],[33] 5.25% [6],[7],[33] 5.25% [6],[7],[33] 5.25% [6],[7],[33] 5.25% [6],[7],[33] 5.25% [8],[11],[28] 5.25% [8],[11],[28] 5.25% [8],[11],[28] 5.25% [8],[11],[28] 5.25% [8],[11],[28] 5.25% [8],[11],[28] 5.25% [8],[11],[28]  
Base Rate Floor 1.00% [6],[7],[33] 1.00% [6],[7],[33] 1.00% [6],[7],[33] 1.00% [6],[7],[33] 1.00% [6],[7],[33] 1.00% [6],[7],[33] 1.00% [6],[7],[33] 1.00% [11],[28] 1.00% [11],[28] 1.00% [11],[28] 1.00% [11],[28] 1.00% [11],[28] 1.00% [11],[28] 1.00% [11],[28]  
Principal amount           $ 42.6 [7],[13],[33]             $ 42.6 [11],[14],[28]    
Amortized Cost $ 31,300,000 [7],[33]             $ 31,100,000 [11],[28]              
Fair Value $ (28,500,000) [4],[7],[33]             $ (29,000,000.0) [1],[11],[28]              
Investment, Identifier [Axis]: Arrotex Australia Group Pty Ltd, Pharmaceuticals, Biotechnology & Life Sciences 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount           $ 109.4             $ 109.4    
Amortized Cost $ 74,000,000.0             $ 73,900,000              
Fair Value $ (73,200,000)             $ (74,500,000)              
Investment, Identifier [Axis]: Arrotex Australia Group Pty Ltd, Pharmaceuticals, Biotechnology & Life Sciences 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% [6],[7],[33] 5.25% [6],[7],[33] 5.25% [6],[7],[33] 5.25% [6],[7],[33] 5.25% [6],[7],[33] 5.25% [6],[7],[33] 5.25% [6],[7],[33] 5.25% [8],[11],[28] 5.25% [8],[11],[28] 5.25% [8],[11],[28] 5.25% [8],[11],[28] 5.25% [8],[11],[28] 5.25% [8],[11],[28] 5.25% [8],[11],[28]  
Base Rate Floor 1.00% [6],[7],[33] 1.00% [6],[7],[33] 1.00% [6],[7],[33] 1.00% [6],[7],[33] 1.00% [6],[7],[33] 1.00% [6],[7],[33] 1.00% [6],[7],[33] 1.00% [11],[28] 1.00% [11],[28] 1.00% [11],[28] 1.00% [11],[28] 1.00% [11],[28] 1.00% [11],[28] 1.00% [11],[28]  
Principal amount           $ 3.1 [7],[13],[33]             $ 3.1 [11],[14],[28]    
Amortized Cost $ 2,200,000 [7],[33]             $ 2,200,000 [11],[28]              
Fair Value $ (2,100,000) [4],[7],[33]             $ (2,100,000) [1],[11],[28]              
Investment, Identifier [Axis]: Arrotex Australia Group Pty Ltd, Pharmaceuticals, Biotechnology & Life Sciences 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount           $ 8.0             $ 8.0    
Amortized Cost $ 5,700,000             $ 5,700,000              
Fair Value $ (5,400,000)             $ (5,400,000)              
Investment, Identifier [Axis]: Arrotex Australia Group Pty Ltd, Pharmaceuticals, Biotechnology & Life Sciences 3 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 1150.00% 1150.00% 1150.00% 1150.00% 1150.00% 1150.00% 1150.00% 11.50% 11.50% 11.50% 11.50% 11.50% 11.50% 11.50%  
Rate, Max PIK 1150.00% 1150.00% 1150.00% 1150.00% 1150.00% 1150.00% 1150.00% 11.50% 11.50% 11.50% 11.50% 11.50% 11.50% 11.50%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount           $ 25.0             $ 25.0    
Amortized Cost $ 16,200,000             $ 16,200,000              
Fair Value $ (16,500,000)             $ (17,000,000.0)              
Investment, Identifier [Axis]: Ascent Resources Utica Holdings LLC / ARU Finance Corp, Common Stock, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 10,193 [32],[49] 10,193 [32],[49] 10,193 [32],[49] 10,193 [32],[49] 10,193 [32],[49] 10,193 [32],[49] 10,193 [32],[49] 10,193 [27],[50] 10,193 [27],[50] 10,193 [27],[50] 10,193 [27],[50] 10,193 [27],[50] 10,193 [27],[50] 10,193 [27],[50]  
Amortized Cost $ 9,700,000 [32],[49]             $ 9,700,000 [27],[50]              
Fair Value $ (2,800,000) [4],[32],[49]             $ (3,600,000) [1],[27],[50]              
Investment, Identifier [Axis]: Ascent Resources Utica Holdings LLC / ARU Finance Corp, Common Stock, Energy | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 13,556 13,556 13,556 13,556 13,556 13,556 13,556 13,556 13,556 13,556 13,556 13,556 13,556 13,556  
Amortized Cost $ 3,600,000             $ 3,600,000              
Fair Value $ (3,700,000)             $ (4,800,000)              
Investment, Identifier [Axis]: Ascent Resources Utica Holdings LLC / ARU Finance Corp, Trade Claim, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 86,607,143 [32],[49] 86,607,143 [32],[49] 86,607,143 [32],[49] 86,607,143 [32],[49] 86,607,143 [32],[49] 86,607,143 [32],[49] 86,607,143 [32],[49] 86,607,143 [27],[50] 86,607,143 [27],[50] 86,607,143 [27],[50] 86,607,143 [27],[50] 86,607,143 [27],[50] 86,607,143 [27],[50] 86,607,143 [27],[50]  
Amortized Cost $ 19,400,000 [32],[49]             $ 19,400,000 [27],[50]              
Fair Value $ (23,400,000) [4],[32],[49]             $ (30,500,000) [1],[27],[50]              
Investment, Identifier [Axis]: Ascent Resources Utica Holdings LLC / ARU Finance Corp, Trade Claim, Energy | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 115,178,571 115,178,571 115,178,571 115,178,571 115,178,571 115,178,571 115,178,571 115,178,571 115,178,571 115,178,571 115,178,571 115,178,571 115,178,571 115,178,571  
Amortized Cost $ 30,500,000             $ 30,500,000              
Fair Value $ (31,200,000)             $ (40,500,000)              
Investment, Identifier [Axis]: Australis Maritime, Common Stock, Transportation                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 53,622,786 [7],[13],[33] 53,622,786 [7],[13],[33] 53,622,786 [7],[13],[33] 53,622,786 [7],[13],[33] 53,622,786 [7],[13],[33] 53,622,786 [7],[13],[33] 53,622,786 [7],[13],[33] 48,936,056 [11],[14],[28] 48,936,056 [11],[14],[28] 48,936,056 [11],[14],[28] 48,936,056 [11],[14],[28] 48,936,056 [11],[14],[28] 48,936,056 [11],[14],[28] 48,936,056 [11],[14],[28]  
Amortized Cost $ 52,300,000 [7],[33]             $ 47,600,000 [11],[28]              
Fair Value (53,700,000) [4],[7],[33]             (49,300,000) [1],[11],[28]              
Investment, Identifier [Axis]: Avenue One PropCo, Private Equity                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (34,500,000)             $ (31,000,000.0)             0
Investment, Identifier [Axis]: Avenue One PropCo, Private Equity, Equity Real Estate Investment Trusts (REITs)                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[13],[32],[33],[34] 34,170,655 34,170,655 34,170,655 34,170,655 34,170,655 34,170,655 34,170,655                
Amortized Cost [7],[32],[33],[34] $ 34,200,000                            
Fair Value [4],[7],[32],[33],[34] (34,500,000)                            
Investment, Identifier [Axis]: Avenue One PropCo, Private Equity, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [11],[14],[27],[28],[35]               30,064,353 30,064,353 30,064,353 30,064,353 30,064,353 30,064,353 30,064,353  
Amortized Cost [11],[27],[28],[35]               $ 30,100,000              
Fair Value [1],[11],[27],[28],[35]               (31,000,000.0)              
Investment, Identifier [Axis]: Avida Holding AB, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (35,500,000)             $ (42,600,000)             (52,300,000)
Investment, Identifier [Axis]: Avida Holding AB, Common Stock, Diversified Financials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [11],[14],[27],[28],[35]               405,023,756 405,023,756 405,023,756 405,023,756 405,023,756 405,023,756 405,023,756  
Amortized Cost [11],[27],[28],[35]               $ 44,600,000              
Fair Value [1],[11],[27],[28],[35]               $ (42,600,000)              
Investment, Identifier [Axis]: Avida Holding AB, Common Stock, Financial Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[13],[32],[33],[34] 405,023,756 405,023,756 405,023,756 405,023,756 405,023,756 405,023,756 405,023,756                
Amortized Cost [7],[32],[33],[34] $ 44,600,000                            
Fair Value [4],[7],[32],[33],[34] $ (35,500,000)                            
Investment, Identifier [Axis]: AxiomSL Ltd, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[7],[20],[21],[41] 5.75% [6],[7],[20],[21],[41] 5.75% [6],[7],[20],[21],[41] 5.75% [6],[7],[20],[21],[41] 5.75% [6],[7],[20],[21],[41] 5.75% [6],[7],[20],[21],[41] 5.75% [6],[7],[20],[21],[41] 6.00% [8],[11],[22],[23],[42] 6.00% [8],[11],[22],[23],[42] 6.00% [8],[11],[22],[23],[42] 6.00% [8],[11],[22],[23],[42] 6.00% [8],[11],[22],[23],[42] 6.00% [8],[11],[22],[23],[42] 6.00% [8],[11],[22],[23],[42]  
Base Rate Floor 1.00% [6],[7],[20],[21],[41] 1.00% [6],[7],[20],[21],[41] 1.00% [6],[7],[20],[21],[41] 1.00% [6],[7],[20],[21],[41] 1.00% [6],[7],[20],[21],[41] 1.00% [6],[7],[20],[21],[41] 1.00% [6],[7],[20],[21],[41] 1.00% [11],[22],[23],[42] 1.00% [11],[22],[23],[42] 1.00% [11],[22],[23],[42] 1.00% [11],[22],[23],[42] 1.00% [11],[22],[23],[42] 1.00% [11],[22],[23],[42] 1.00% [11],[22],[23],[42]  
Principal amount $ 34,600,000 [7],[13],[20],[21],[41]             $ 34,700,000 [11],[14],[22],[23],[42]              
Amortized Cost 34,100,000 [7],[20],[21],[41]             34,100,000 [11],[22],[23],[42]              
Fair Value $ (33,800,000) [4],[7],[20],[21],[41]             $ (33,700,000) [1],[11],[22],[23],[42]              
Investment, Identifier [Axis]: AxiomSL Ltd, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 2,500,000 [13],[19]             $ 2,500,000 [14],[18]              
Amortized Cost 2,500,000 [19]             2,400,000 [18]              
Fair Value $ (2,400,000) [4],[19]             $ (2,400,000) [1],[18]              
Investment, Identifier [Axis]: AxiomSL Ltd, Software & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 2,300,000 [13],[19]             $ 2,300,000 [14],[18]              
Amortized Cost 2,300,000 [19]             2,300,000 [18]              
Fair Value $ (2,200,000) [4],[19]             $ (2,200,000) [1],[18]              
Investment, Identifier [Axis]: BGB Group LLC, Media & Entertainment | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 54,200,000             $ 54,400,000              
Amortized Cost 53,800,000             54,000,000.0              
Fair Value $ (52,400,000)             $ (53,000,000.0)              
Investment, Identifier [Axis]: BGB Group LLC, Media & Entertainment 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[15],[16],[17],[20],[21],[41] 5.75% [6],[15],[16],[17],[20],[21],[41] 5.75% [6],[15],[16],[17],[20],[21],[41] 5.75% [6],[15],[16],[17],[20],[21],[41] 5.75% [6],[15],[16],[17],[20],[21],[41] 5.75% [6],[15],[16],[17],[20],[21],[41] 5.75% [6],[15],[16],[17],[20],[21],[41] 5.75% [8],[9],[10],[12],[22],[23],[42] 5.75% [8],[9],[10],[12],[22],[23],[42] 5.75% [8],[9],[10],[12],[22],[23],[42] 5.75% [8],[9],[10],[12],[22],[23],[42] 5.75% [8],[9],[10],[12],[22],[23],[42] 5.75% [8],[9],[10],[12],[22],[23],[42] 5.75% [8],[9],[10],[12],[22],[23],[42]  
Base Rate Floor 1.00% [6],[15],[16],[17],[20],[21],[41] 1.00% [6],[15],[16],[17],[20],[21],[41] 1.00% [6],[15],[16],[17],[20],[21],[41] 1.00% [6],[15],[16],[17],[20],[21],[41] 1.00% [6],[15],[16],[17],[20],[21],[41] 1.00% [6],[15],[16],[17],[20],[21],[41] 1.00% [6],[15],[16],[17],[20],[21],[41] 1.00% [9],[10],[12],[22],[23],[42] 1.00% [9],[10],[12],[22],[23],[42] 1.00% [9],[10],[12],[22],[23],[42] 1.00% [9],[10],[12],[22],[23],[42] 1.00% [9],[10],[12],[22],[23],[42] 1.00% [9],[10],[12],[22],[23],[42] 1.00% [9],[10],[12],[22],[23],[42]  
Principal amount $ 110,800,000 [13],[15],[16],[17],[20],[21],[41]             $ 111,100,000 [9],[10],[12],[14],[22],[23],[42]              
Amortized Cost 110,000,000.0 [15],[16],[17],[20],[21],[41]             110,300,000 [9],[10],[12],[22],[23],[42]              
Fair Value $ (107,300,000) [4],[15],[16],[17],[20],[21],[41]             $ (108,400,000) [1],[9],[10],[12],[22],[23],[42]              
Investment, Identifier [Axis]: BGB Group LLC, Media & Entertainment 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 19,900,000 [13],[19]             $ 19,900,000 [14],[18]              
Amortized Cost 19,900,000 [19]             19,900,000 [18]              
Fair Value $ (19,300,000) [4],[19]             $ (19,500,000) [1],[18]              
Investment, Identifier [Axis]: Bankers Healthcare Group LLC, Term Loan, Diversified Financials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11],[28]               3.93% 3.93% 3.93% 3.93% 3.93% 3.93% 3.93%  
Principal amount [11],[14],[28]               $ 11,300,000              
Amortized Cost [11],[28]               11,300,000              
Fair Value [1],[11],[28]               $ (11,300,000)              
Investment, Identifier [Axis]: Bankers Healthcare Group LLC, Term Loan, Financial Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[33] 3.93% 3.93% 3.93% 3.93% 3.93% 3.93% 3.93%                
Base Rate Floor [6],[7],[33] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount [7],[13],[33] $ 11,300,000                            
Amortized Cost [7],[33] 11,300,000                            
Fair Value [4],[7],[33] $ (11,400,000)                            
Investment, Identifier [Axis]: Barbri Inc, Consumer Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 47,100,000             $ 47,200,000              
Amortized Cost 47,100,000             47,300,000              
Fair Value $ (46,800,000)             $ (46,900,000)              
Investment, Identifier [Axis]: Barbri Inc, Consumer Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[16],[17],[20],[21],[41] 5.75% [6],[16],[17],[20],[21],[41] 5.75% [6],[16],[17],[20],[21],[41] 5.75% [6],[16],[17],[20],[21],[41] 5.75% [6],[16],[17],[20],[21],[41] 5.75% [6],[16],[17],[20],[21],[41] 5.75% [6],[16],[17],[20],[21],[41] 5.75% [8],[9],[10],[22],[23],[42] 5.75% [8],[9],[10],[22],[23],[42] 5.75% [8],[9],[10],[22],[23],[42] 5.75% [8],[9],[10],[22],[23],[42] 5.75% [8],[9],[10],[22],[23],[42] 5.75% [8],[9],[10],[22],[23],[42] 5.75% [8],[9],[10],[22],[23],[42]  
Base Rate Floor 0.80% [6],[16],[17],[20],[21],[41] 0.80% [6],[16],[17],[20],[21],[41] 0.80% [6],[16],[17],[20],[21],[41] 0.80% [6],[16],[17],[20],[21],[41] 0.80% [6],[16],[17],[20],[21],[41] 0.80% [6],[16],[17],[20],[21],[41] 0.80% [6],[16],[17],[20],[21],[41] 0.80% [9],[10],[22],[23],[42] 0.80% [9],[10],[22],[23],[42] 0.80% [9],[10],[22],[23],[42] 0.80% [9],[10],[22],[23],[42] 0.80% [9],[10],[22],[23],[42] 0.80% [9],[10],[22],[23],[42] 0.80% [9],[10],[22],[23],[42]  
Principal amount $ 61,300,000 [13],[16],[17],[20],[21],[41]             $ 61,500,000 [9],[10],[14],[22],[23],[42]              
Amortized Cost 57,700,000 [16],[17],[20],[21],[41]             57,700,000 [9],[10],[22],[23],[42]              
Fair Value $ (60,900,000) [4],[16],[17],[20],[21],[41]             $ (61,000,000.0) [1],[9],[10],[22],[23],[42]              
Investment, Identifier [Axis]: Barbri Inc, Consumer Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [8],[9],[10],[11] 5.75% [8],[9],[10],[11] 5.75% [8],[9],[10],[11] 5.75% [8],[9],[10],[11] 5.75% [8],[9],[10],[11] 5.75% [8],[9],[10],[11] 5.75% [8],[9],[10],[11]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [9],[10],[11] 0.80% [9],[10],[11] 0.80% [9],[10],[11] 0.80% [9],[10],[11] 0.80% [9],[10],[11] 0.80% [9],[10],[11] 0.80% [9],[10],[11]  
Principal amount $ 29,900,000 [7],[13]             $ 70,300,000 [9],[10],[11],[14]              
Amortized Cost 29,900,000 [7]             70,000,000.0 [9],[10],[11]              
Fair Value $ (29,700,000) [4],[7]             $ (69,700,000) [1],[9],[10],[11]              
Investment, Identifier [Axis]: Barbri Inc, Consumer Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[16],[17] 5.75% [6],[16],[17] 5.75% [6],[16],[17] 5.75% [6],[16],[17] 5.75% [6],[16],[17] 5.75% [6],[16],[17] 5.75% [6],[16],[17] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18]  
Base Rate Floor 0.80% [6],[16],[17] 0.80% [6],[16],[17] 0.80% [6],[16],[17] 0.80% [6],[16],[17] 0.80% [6],[16],[17] 0.80% [6],[16],[17] 0.80% [6],[16],[17] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 34,700,000 [13],[16],[17]             $ 9,100,000 [14],[18]              
Amortized Cost 34,400,000 [16],[17]             9,100,000 [18]              
Fair Value $ (34,400,000) [4],[16],[17]             $ (9,100,000) [1],[18]              
Investment, Identifier [Axis]: Barbri Inc, Consumer Services 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base Rate Floor [6],[7] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [7],[13] $ 5,600,000                            
Amortized Cost [7] 5,600,000                            
Fair Value [4],[7] $ (5,500,000)                            
Investment, Identifier [Axis]: Barbri Inc, Consumer Services 5                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base Rate Floor [6],[19] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[19] $ 9,100,000                            
Amortized Cost [19] 9,100,000                            
Fair Value [4],[19] $ (9,100,000)                            
Investment, Identifier [Axis]: BearCom Acquisition Corp, Technology Hardware & Equipment 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Rate, PIK 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Rate, Max PIK 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 2,200,000             $ 2,200,000              
Amortized Cost 2,200,000             2,200,000              
Fair Value $ (2,200,000)             $ (2,200,000)              
Investment, Identifier [Axis]: BearCom Acquisition Corp, Technology Hardware & Equipment 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Rate, PIK 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Rate, Max PIK 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount             $ 14.2             $ 14.3  
Amortized Cost $ 10,600,000             $ 10,600,000              
Fair Value $ (10,400,000)             $ (10,300,000)              
Investment, Identifier [Axis]: BearCom Acquisition Corp, Technology Hardware & Equipment 3 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount             $ 1.3             $ 1.3  
Amortized Cost $ 1,000,000.0             $ 1,000,000.0              
Fair Value (1,000,000.0)             (1,000,000.0)              
Investment, Identifier [Axis]: Belk Inc 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value (12,500,000)             (8,800,000)              
Investment, Identifier [Axis]: Belk Inc 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value (18,700,000)             (19,400,000)              
Investment, Identifier [Axis]: Belk Inc 2, Senior Secured Loans—First Lien -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               (19,400,000)             (21,900,000)
Investment, Identifier [Axis]: Belk Inc 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value 0             (3,300,000)              
Investment, Identifier [Axis]: Belk Inc, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ 0             0              
Investment, Identifier [Axis]: Belk Inc, Common Stock, Consumer Discretionary Distribution & Retail                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[32],[43] 94,950 94,950 94,950 94,950 94,950 94,950 94,950                
Amortized Cost [7],[32],[43] $ 0                            
Fair Value [4],[7],[32],[43] $ 0                            
Investment, Identifier [Axis]: Belk Inc, Common Stock, Consumer Discretionary Distribution & Retail | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 381 381 381 381 381 381 381                
Amortized Cost $ 0                            
Fair Value $ 0                            
Investment, Identifier [Axis]: Belk Inc, Common Stock, Equity/Other                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ 0             0
Investment, Identifier [Axis]: Belk Inc, Common Stock, Retailing                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [11],[27],[44]               94,950 94,950 94,950 94,950 94,950 94,950 94,950  
Amortized Cost [11],[27],[44]               $ 0              
Fair Value [1],[11],[27],[44]               $ 0              
Investment, Identifier [Axis]: Belk Inc, Common Stock, Retailing | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares               381 381 381 381 381 381 381  
Amortized Cost               $ 0              
Fair Value               $ 0              
Investment, Identifier [Axis]: Belk Inc, Consumer Discretionary Distribution & Retail 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[39],[43] 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%                
Base Rate Floor [6],[7],[39],[43] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [7],[13],[39],[43] $ 21,900,000                            
Amortized Cost [7],[39],[43] 21,800,000                            
Fair Value [4],[7],[39],[43] $ (18,700,000)                            
Investment, Identifier [Axis]: Belk Inc, Consumer Discretionary Distribution & Retail 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%                
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount $ 600,000                            
Amortized Cost 600,000                            
Fair Value $ (500,000)                            
Investment, Identifier [Axis]: Belk Inc, Consumer Discretionary Distribution & Retail 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[29],[32],[39],[43] 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%                
Rate, PIK [6],[7],[29],[32],[39],[43] 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%                
Rate, Max PIK [6],[7],[29],[32],[39],[43] 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%                
Principal amount [7],[13],[29],[32],[39],[43] $ 72,100,000                            
Amortized Cost [7],[29],[32],[39],[43] 42,300,000                            
Fair Value [4],[7],[29],[32],[39],[43] $ (12,500,000)                            
Investment, Identifier [Axis]: Belk Inc, Consumer Discretionary Distribution & Retail 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%                
Rate, Max PIK 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%                
Rate, Stated interest rate 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%                
Principal amount $ 3,100,000                            
Amortized Cost 1,700,000                            
Fair Value $ (500,000)                            
Investment, Identifier [Axis]: Belk Inc, Consumer Discretionary Distribution & Retail 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK [6],[7],[29],[32],[43] 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%                
Rate, Max PIK [6],[7],[29],[32],[43] 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%                
Principal amount [7],[13],[29],[32],[43] $ 28,900,000                            
Amortized Cost [7],[29],[32],[43] 4,200,000                            
Fair Value [4],[7],[29],[32],[43] $ 0                            
Investment, Identifier [Axis]: Belk Inc, Retailing 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11],[40],[44]               7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%  
Base Rate Floor [11],[40],[44]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [11],[14],[40],[44]               $ 21,900,000              
Amortized Cost [11],[40],[44]               21,800,000              
Fair Value [1],[11],[40],[44]               $ (19,400,000)              
Investment, Identifier [Axis]: Belk Inc, Retailing 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate               7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%  
Base Rate Floor               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount               $ 600,000              
Amortized Cost               600,000              
Fair Value               $ (600,000)              
Investment, Identifier [Axis]: Belk Inc, Retailing 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK [8],[11],[24],[27],[40],[44]               8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%  
Rate, Max PIK [8],[11],[24],[27],[40],[44]               8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%  
Rate, Stated interest rate [8],[11],[24],[27],[40],[44]               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Principal amount [11],[14],[24],[27],[40],[44]               $ 71,000,000.0              
Amortized Cost [11],[24],[27],[40],[44]               42,500,000              
Fair Value [1],[11],[24],[27],[40],[44]               $ (8,800,000)              
Investment, Identifier [Axis]: Belk Inc, Retailing 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK               8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%  
Rate, Max PIK               8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%  
Rate, Stated interest rate               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Base Rate Floor                
Principal amount               $ 3,100,000              
Amortized Cost               1,700,000              
Fair Value               $ (400,000)              
Investment, Identifier [Axis]: Belk Inc, Retailing 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK [8],[11],[24],[27],[44]               10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%  
Rate, Max PIK [8],[11],[24],[27],[44]               10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%  
Principal amount [11],[14],[24],[27],[44]               $ 28,200,000              
Amortized Cost [11],[24],[27],[44]               4,200,000              
Fair Value [1],[11],[24],[27],[44]               (3,300,000)              
Investment, Identifier [Axis]: Belk Inc, Senior Secured Loans—First Lien -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ (8,800,000)             (49,200,000)
Investment, Identifier [Axis]: Big Bus Tours Ltd, Consumer Services 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 850.00% 850.00% 850.00% 850.00% 850.00% 850.00% 850.00% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%  
Rate, Max PIK 850.00% 850.00% 850.00% 850.00% 850.00% 850.00% 850.00% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 18,100,000             $ 10,700,000              
Amortized Cost 18,100,000             10,700,000              
Fair Value $ (16,900,000)             $ (8,800,000)              
Investment, Identifier [Axis]: Big Bus Tours Ltd, Consumer Services 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 850.00% 850.00% 850.00% 850.00% 850.00% 850.00% 850.00% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%  
Rate, Max PIK 850.00% 850.00% 850.00% 850.00% 850.00% 850.00% 850.00% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount | €       € 12.7             € 12.6        
Amortized Cost $ 14,100,000             $ 14,000,000.0              
Fair Value (12,800,000)             $ (11,000,000.0)              
Investment, Identifier [Axis]: Big Bus Tours Ltd, Consumer Services 3 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK               8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%  
Rate, Max PIK               8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%  
Base Rate Floor               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount               $ 7,200,000              
Amortized Cost               7,200,000              
Fair Value               (5,900,000)              
Investment, Identifier [Axis]: Borden (New Dairy Opco) 2, Senior Secured Loans—First Lien                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               0             (42,000,000.0)
Investment, Identifier [Axis]: Borden (New Dairy Opco), Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (6,700,000)             (4,800,000)              
Investment, Identifier [Axis]: Borden (New Dairy Opco), Common Stock, Equity/Other                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ (4,800,000)             (7,700,000)
Investment, Identifier [Axis]: Borden (New Dairy Opco), Common Stock, Food, Beverage & Tobacco                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 11,167,000 [32],[43],[47],[51] 11,167,000 [32],[43],[47],[51] 11,167,000 [32],[43],[47],[51] 11,167,000 [32],[43],[47],[51] 11,167,000 [32],[43],[47],[51] 11,167,000 [32],[43],[47],[51] 11,167,000 [32],[43],[47],[51] 11,167,000 [27],[44],[48],[52] 11,167,000 [27],[44],[48],[52] 11,167,000 [27],[44],[48],[52] 11,167,000 [27],[44],[48],[52] 11,167,000 [27],[44],[48],[52] 11,167,000 [27],[44],[48],[52] 11,167,000 [27],[44],[48],[52]  
Amortized Cost $ 9,100,000 [32],[43],[47],[51]             $ 9,100,000 [27],[44],[48],[52]              
Fair Value $ (6,700,000) [4],[32],[43],[47],[51]             (4,800,000) [1],[27],[44],[48],[52]              
Investment, Identifier [Axis]: Borden (New Dairy Opco), Senior Secured Loans—First Lien -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               0             (9,000,000.0)
Investment, Identifier [Axis]: Borden Dairy Co, Senior Secured Loans—First Lien                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ 0             0
Investment, Identifier [Axis]: Bowery Farming Inc, Food, Beverage & Tobacco                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 10.00% [6],[7] 10.00% [6],[7] 10.00% [6],[7] 10.00% [6],[7] 10.00% [6],[7] 10.00% [6],[7] 10.00% [6],[7] 10.00% [8],[11] 10.00% [8],[11] 10.00% [8],[11] 10.00% [8],[11] 10.00% [8],[11] 10.00% [8],[11] 10.00% [8],[11]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Principal amount $ 75,000,000.0 [7],[13]             $ 75,000,000.0 [11],[14]              
Amortized Cost 74,400,000 [7]             74,400,000 [11]              
Fair Value $ (70,200,000) [4],[7]             $ (70,300,000) [1],[11]              
Investment, Identifier [Axis]: Bowery Farming Inc, Warrants, Food, Beverage & Tobacco                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 161,828 [7],[32] 161,828 [7],[32] 161,828 [7],[32] 161,828 [7],[32] 161,828 [7],[32] 161,828 [7],[32] 161,828 [7],[32] 161,828 [11],[27] 161,828 [11],[27] 161,828 [11],[27] 161,828 [11],[27] 161,828 [11],[27] 161,828 [11],[27] 161,828 [11],[27]  
Amortized Cost $ 0.0 [7],[32]             $ 0 [11],[27]              
Fair Value $ (2,100,000) [4],[7],[32]             $ (2,500,000) [1],[11],[27]              
Investment, Identifier [Axis]: Bugaboo International BV, Consumer Durables & Apparel | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%  
Rate, PIK 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Rate, Max PIK 7.80% 7.80% 7.80% 7.80% 7.80% 7.80% 7.80% 7.80% 7.80% 7.80% 7.80% 7.80% 7.80% 7.80%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | €       € 35.0             € 35.0        
Amortized Cost $ 41,000,000.0             $ 41,000,000.0              
Fair Value $ (38,000,000.0)             $ (37,400,000)              
Investment, Identifier [Axis]: Byrider Finance LLC, Private Equity, Automobiles & Components                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 54,407 [7],[13],[32],[53] 54,407 [7],[13],[32],[53] 54,407 [7],[13],[32],[53] 54,407 [7],[13],[32],[53] 54,407 [7],[13],[32],[53] 54,407 [7],[13],[32],[53] 54,407 [7],[13],[32],[53] 54,407 [11],[14],[28],[54] 54,407 [11],[14],[28],[54] 54,407 [11],[14],[28],[54] 54,407 [11],[14],[28],[54] 54,407 [11],[14],[28],[54] 54,407 [11],[14],[28],[54] 54,407 [11],[14],[28],[54]  
Amortized Cost $ 0 [7],[32],[53]             $ 0 [11],[28],[54]              
Fair Value $ 0 [4],[7],[32],[53]             $ 0 [1],[11],[28],[54]              
Investment, Identifier [Axis]: Byrider Finance LLC, Structured Mezzanine, Automobiles & Components 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11]               10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50%  
Base Rate Floor [11]               0.30% 0.30% 0.30% 0.30% 0.30% 0.30% 0.30%  
Principal amount [11],[14]               $ 16,200,000              
Amortized Cost [11]               16,200,000              
Fair Value [1],[11]               $ (16,100,000)              
Investment, Identifier [Axis]: Byrider Finance LLC, Structured Mezzanine, Automobiles & Components 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[18]               10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50%  
Base Rate Floor [18]               0.30% 0.30% 0.30% 0.30% 0.30% 0.30% 0.30%  
Principal amount [14],[18]               $ 6,800,000              
Amortized Cost [18]               6,800,000              
Fair Value [1],[18]               $ (6,800,000)              
Investment, Identifier [Axis]: Byrider Finance LLC, Term Loan, Automobiles & Components                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 5,000,000 [7],[13],[32],[53] 5,000,000 [7],[13],[32],[53] 5,000,000 [7],[13],[32],[53] 5,000,000 [7],[13],[32],[53] 5,000,000 [7],[13],[32],[53] 5,000,000 [7],[13],[32],[53] 5,000,000 [7],[13],[32],[53] 5,000,000 [11],[14],[28],[54] 5,000,000 [11],[14],[28],[54] 5,000,000 [11],[14],[28],[54] 5,000,000 [11],[14],[28],[54] 5,000,000 [11],[14],[28],[54] 5,000,000 [11],[14],[28],[54] 5,000,000 [11],[14],[28],[54]  
Amortized Cost $ 5,000,000.0 [7],[32],[53]             $ 5,000,000.0 [11],[28],[54]              
Fair Value $ (3,900,000) [4],[7],[32],[53]             $ (5,000,000.0) [1],[11],[28],[54]              
Investment, Identifier [Axis]: CDS US Intermediate Holdings Inc, Warrant, Media & Entertainment                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 2,023,714 [7],[32],[33] 2,023,714 [7],[32],[33] 2,023,714 [7],[32],[33] 2,023,714 [7],[32],[33] 2,023,714 [7],[32],[33] 2,023,714 [7],[32],[33] 2,023,714 [7],[32],[33] 2,023,714 [11],[27],[28] 2,023,714 [11],[27],[28] 2,023,714 [11],[27],[28] 2,023,714 [11],[27],[28] 2,023,714 [11],[27],[28] 2,023,714 [11],[27],[28] 2,023,714 [11],[27],[28]  
Amortized Cost $ 0 [7],[32],[33]             $ 0 [11],[27],[28]              
Fair Value $ (4,400,000) [4],[7],[32],[33]             $ (4,000,000.0) [1],[11],[27],[28]              
Investment, Identifier [Axis]: CFC Underwriting Ltd, Insurance                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[19],[33] 5.50% [6],[19],[33] 5.50% [6],[19],[33] 5.50% [6],[19],[33] 5.50% [6],[19],[33] 5.50% [6],[19],[33] 5.50% [6],[19],[33] 5.50% [8],[18],[28] 5.50% [8],[18],[28] 5.50% [8],[18],[28] 5.50% [8],[18],[28] 5.50% [8],[18],[28] 5.50% [8],[18],[28] 5.50% [8],[18],[28]  
Rate, PIK 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Rate, Max PIK 2.80% [6],[19],[33] 2.80% [6],[19],[33] 2.80% [6],[19],[33] 2.80% [6],[19],[33] 2.80% [6],[19],[33] 2.80% [6],[19],[33] 2.80% [6],[19],[33] 2.80% [8],[18],[28] 2.80% [8],[18],[28] 2.80% [8],[18],[28] 2.80% [8],[18],[28] 2.80% [8],[18],[28] 2.80% [8],[18],[28] 2.80% [8],[18],[28]  
Base Rate Floor 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [18],[28] 0.00% [18],[28] 0.00% [18],[28] 0.00% [18],[28] 0.00% [18],[28] 0.00% [18],[28] 0.00% [18],[28]  
Principal amount | £         £ 4.7 [13],[19],[33]             £ 4.7 [14],[18],[28]      
Amortized Cost $ 5,700,000 [19],[33]             $ 5,700,000 [18],[28]              
Fair Value $ (5,700,000) [4],[19],[33]             $ (5,700,000) [1],[18],[28]              
Investment, Identifier [Axis]: CFC Underwriting Ltd, Insurance | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Rate, PIK 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Rate, Max PIK 2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80%  
Base Rate Floor 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount $ 39,500,000             $ 39,500,000              
Amortized Cost 39,100,000             38,300,000              
Fair Value $ (39,500,000)             $ (39,200,000)              
Investment, Identifier [Axis]: CSafe Global, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[7],[15],[16],[17],[20],[21],[41] 6.25% [6],[7],[15],[16],[17],[20],[21],[41] 6.25% [6],[7],[15],[16],[17],[20],[21],[41] 6.25% [6],[7],[15],[16],[17],[20],[21],[41] 6.25% [6],[7],[15],[16],[17],[20],[21],[41] 6.25% [6],[7],[15],[16],[17],[20],[21],[41] 6.25% [6],[7],[15],[16],[17],[20],[21],[41] 6.25% [8],[11],[12],[22],[23],[42] 6.25% [8],[11],[12],[22],[23],[42] 6.25% [8],[11],[12],[22],[23],[42] 6.25% [8],[11],[12],[22],[23],[42] 6.25% [8],[11],[12],[22],[23],[42] 6.25% [8],[11],[12],[22],[23],[42] 6.25% [8],[11],[12],[22],[23],[42]  
Base Rate Floor 1.00% [6],[7],[15],[16],[17],[20],[21],[41] 1.00% [6],[7],[15],[16],[17],[20],[21],[41] 1.00% [6],[7],[15],[16],[17],[20],[21],[41] 1.00% [6],[7],[15],[16],[17],[20],[21],[41] 1.00% [6],[7],[15],[16],[17],[20],[21],[41] 1.00% [6],[7],[15],[16],[17],[20],[21],[41] 1.00% [6],[7],[15],[16],[17],[20],[21],[41] 0.80% [9],[10],[11],[12],[22],[23],[42] 0.80% [9],[10],[11],[12],[22],[23],[42] 0.80% [9],[10],[11],[12],[22],[23],[42] 0.80% [9],[10],[11],[12],[22],[23],[42] 0.80% [9],[10],[11],[12],[22],[23],[42] 0.80% [9],[10],[11],[12],[22],[23],[42] 0.80% [9],[10],[11],[12],[22],[23],[42]  
Principal amount $ 186,400,000 [7],[13],[15],[16],[17],[20],[21],[41]             $ 186,800,000 [9],[10],[11],[12],[14],[22],[23],[42]              
Amortized Cost 181,200,000 [7],[15],[16],[17],[20],[21],[41]             181,500,000 [9],[10],[11],[12],[22],[23],[42]              
Fair Value $ (186,500,000) [4],[7],[15],[16],[17],[20],[21],[41]             $ (186,800,000) [1],[9],[10],[11],[12],[22],[23],[42]              
Investment, Identifier [Axis]: CSafe Global, Capital Goods 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 59,200,000             $ 59,400,000              
Amortized Cost 59,100,000             59,300,000              
Fair Value $ (59,200,000)             $ (59,400,000)              
Investment, Identifier [Axis]: CSafe Global, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount | £         £ 27.1 [7],[13]             £ 27.2 [11],[14]      
Amortized Cost $ 35,800,000 [7]             $ 35,900,000 [11]              
Fair Value $ (33,500,000) [4],[7]             $ (32,800,000) [1],[11]              
Investment, Identifier [Axis]: CSafe Global, Capital Goods 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 17,200,000             $ 17,300,000              
Amortized Cost 17,200,000             17,300,000              
Fair Value $ (17,200,000)             $ (17,300,000)              
Investment, Identifier [Axis]: CSafe Global, Capital Goods 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[7],[41] 6.25% [6],[7],[41] 6.25% [6],[7],[41] 6.25% [6],[7],[41] 6.25% [6],[7],[41] 6.25% [6],[7],[41] 6.25% [6],[7],[41] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11]  
Base Rate Floor 1.00% [6],[7],[41] 1.00% [6],[7],[41] 1.00% [6],[7],[41] 1.00% [6],[7],[41] 1.00% [6],[7],[41] 1.00% [6],[7],[41] 1.00% [6],[7],[41] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 11,800,000 [7],[13],[41]             $ 11,800,000 [11],[14]              
Amortized Cost 11,800,000 [7],[41]             11,800,000 [11]              
Fair Value $ (11,800,000) [4],[7],[41]             $ (11,800,000) [1],[11]              
Investment, Identifier [Axis]: CSafe Global, Capital Goods 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 34,900,000 [13],[19]             $ 34,900,000 [14],[18]              
Amortized Cost 34,900,000 [19]             34,900,000 [18]              
Fair Value $ (34,700,000) [4],[19]             $ (34,700,000) [1],[18]              
Investment, Identifier [Axis]: CTI Foods Holding Co LLC, Common Stock, Food, Beverage & Tobacco                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 5,892 [7],[32] 5,892 [7],[32] 5,892 [7],[32] 5,892 [7],[32] 5,892 [7],[32] 5,892 [7],[32] 5,892 [7],[32] 5,892 [11],[27] 5,892 [11],[27] 5,892 [11],[27] 5,892 [11],[27] 5,892 [11],[27] 5,892 [11],[27] 5,892 [11],[27]  
Amortized Cost $ 700,000 [7],[32]             $ 700,000 [11],[27]              
Fair Value $ 0 [4],[7],[32]             $ 0 [1],[11],[27]              
Investment, Identifier [Axis]: Caldic BV, Consumer Discretionary Distribution & Retail 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[33],[39] 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50%                
Base Rate Floor [6],[7],[33],[39] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | € [7],[13],[33],[39]       € 0.8                      
Amortized Cost [7],[33],[39] $ 900,000                            
Fair Value [4],[7],[33],[39] $ (900,000)                            
Investment, Identifier [Axis]: Caldic BV, Consumer Discretionary Distribution & Retail 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[33],[39],[41] 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75%                
Base Rate Floor [6],[33],[39],[41] 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount [13],[33],[39],[41] $ 1,400,000                            
Amortized Cost [33],[39],[41] 1,400,000                            
Fair Value [4],[33],[39],[41] $ (1,400,000)                            
Investment, Identifier [Axis]: Caldic BV, Consumer Discretionary Distribution & Retail 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[33] 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25%                
Base Rate Floor [6],[7],[33] 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount [7],[13],[33] $ 40,000,000.0                            
Amortized Cost [7],[33] 39,000,000.0                            
Fair Value [4],[7],[33] $ (39,000,000.0)                            
Investment, Identifier [Axis]: Caldic BV, Retailing 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11],[28],[40]               3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50%  
Base Rate Floor [11],[28],[40]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | € [11],[14],[28],[40]                     € 0.8        
Amortized Cost [11],[28],[40]               $ 900,000              
Fair Value [1],[11],[28],[40]               $ (800,000)              
Investment, Identifier [Axis]: Caldic BV, Retailing 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11],[28],[40]               3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75%  
Base Rate Floor [11],[28],[40]               0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount [11],[14],[28],[40]               $ 1,400,000              
Amortized Cost [11],[28],[40]               1,400,000              
Fair Value [1],[11],[28],[40]               $ (1,400,000)              
Investment, Identifier [Axis]: Caldic BV, Retailing 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11],[28]               7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25%  
Base Rate Floor [11],[28]               0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount [11],[14],[28]               $ 40,000,000.0              
Amortized Cost [11],[28]               39,000,000.0              
Fair Value [1],[11],[28]               $ (38,200,000)              
Investment, Identifier [Axis]: Callodine Commercial Finance LLC, 2L Term Loan A, Diversified Financials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11]               9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%  
Base Rate Floor [11]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [11],[14]               $ 125,000,000.0              
Amortized Cost [11]               119,300,000              
Fair Value [1],[11]               $ (125,300,000)              
Investment, Identifier [Axis]: Callodine Commercial Finance LLC, 2L Term Loan A, Financial Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7] 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%                
Base Rate Floor [6],[7] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [7],[13] $ 125,000,000.0                            
Amortized Cost [7] 119,600,000                            
Fair Value [4],[7] $ (125,600,000)                            
Investment, Identifier [Axis]: Callodine Commercial Finance LLC, 2L Term Loan B, Diversified Financials 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11]               9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%  
Base Rate Floor [11]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [11],[14]               $ 12,000,000.0              
Amortized Cost [11]               12,000,000.0              
Fair Value [1],[11]               $ (12,000,000.0)              
Investment, Identifier [Axis]: Callodine Commercial Finance LLC, 2L Term Loan B, Diversified Financials 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[18]               9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%  
Base Rate Floor [18]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [14],[18]               $ 36,100,000              
Amortized Cost [18]               36,100,000              
Fair Value [1],[18]               $ (36,100,000)              
Investment, Identifier [Axis]: Callodine Commercial Finance LLC, 2L Term Loan B, Financial Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7] 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%                
Base Rate Floor [6],[7] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [7],[13] $ 12,000,000.0                            
Amortized Cost [7] 12,000,000.0                            
Fair Value [4],[7] $ (12,100,000)                            
Investment, Identifier [Axis]: Callodine Commercial Finance LLC, 2L Term Loan B, Financial Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19] 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%                
Base Rate Floor [6],[19] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[19] $ 36,100,000                            
Amortized Cost [19] 36,100,000                            
Fair Value [4],[19] $ (36,200,000)                            
Investment, Identifier [Axis]: Capital Automotive LP, Private Equity, Equity Real Estate Investment Trusts (REITs)                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[13],[33] 21,640,936 21,640,936 21,640,936 21,640,936 21,640,936 21,640,936 21,640,936                
Amortized Cost [7],[33] $ 23,700,000                            
Fair Value [4],[7],[33] $ (31,100,000)                            
Investment, Identifier [Axis]: Capital Automotive LP, Private Equity, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [11],[14],[28]               21,640,936 21,640,936 21,640,936 21,640,936 21,640,936 21,640,936 21,640,936  
Amortized Cost [11],[28]               $ 23,700,000              
Fair Value [1],[11],[28]               $ (27,000,000.0)              
Investment, Identifier [Axis]: Capital Automotive LP, Structured Mezzanine, Equity Real Estate Investment Trusts (REITs)                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate [6],[7],[33] 11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%                
Principal amount [7],[13],[33] $ 41,900,000                            
Amortized Cost [7],[33] 41,200,000                            
Fair Value [4],[7],[33] $ (41,900,000)                            
Investment, Identifier [Axis]: Capital Automotive LP, Structured Mezzanine, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate [8],[11],[28]               11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%  
Principal amount [11],[14],[28]               $ 42,400,000              
Amortized Cost [11],[28]               41,700,000              
Fair Value [1],[11],[28]               $ (42,400,000)              
Investment, Identifier [Axis]: Careismatic Brands Inc, Health Care Equipment & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7] 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%                
Base Rate Floor [6],[7] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [7],[13] $ 15,000,000.0                            
Amortized Cost [7] 15,000,000.0                            
Fair Value [4],[7] $ (15,000,000.0)                            
Investment, Identifier [Axis]: Careismatic Brands Inc, Health Care Equipment & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19] 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%                
Base Rate Floor [6],[19] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[19] $ 15,000,000.0                            
Amortized Cost [19] 15,000,000.0                            
Fair Value [4],[19] $ (15,000,000.0)                            
Investment, Identifier [Axis]: Catalina Marketing Corp, Common Stock, Media & Entertainment                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [11],[27]               6,522 6,522 6,522 6,522 6,522 6,522 6,522  
Amortized Cost [11],[27]               $ 0              
Fair Value [1],[11],[27]               $ 0              
Investment, Identifier [Axis]: Cengage Learning, Inc, Common Stock, Media & Entertainment                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 227,802 [7],[32] 227,802 [7],[32] 227,802 [7],[32] 227,802 [7],[32] 227,802 [7],[32] 227,802 [7],[32] 227,802 [7],[32] 227,802 [11],[27] 227,802 [11],[27] 227,802 [11],[27] 227,802 [11],[27] 227,802 [11],[27] 227,802 [11],[27] 227,802 [11],[27]  
Amortized Cost $ 7,500,000 [7],[32]             $ 7,600,000 [11],[27]              
Fair Value $ (3,600,000) [4],[7],[32]             $ (3,600,000) [1],[11],[27]              
Investment, Identifier [Axis]: Cimarron Energy Inc, Common Stock, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [11],[27]               4,302,293 4,302,293 4,302,293 4,302,293 4,302,293 4,302,293 4,302,293  
Amortized Cost [11],[27]               $ 0              
Fair Value [1],[11],[27]               $ 0              
Investment, Identifier [Axis]: Cimarron Energy Inc, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11],[24],[27]               9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%  
Base Rate Floor [11],[24],[27]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [11],[14],[24],[27]               $ 7,500,000              
Amortized Cost [11],[24],[27]               4,800,000              
Fair Value [1],[11],[24],[27]               $ (3,700,000)              
Investment, Identifier [Axis]: Cimarron Energy Inc, Participation Option, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [11],[27]               25,000,000 25,000,000 25,000,000 25,000,000 25,000,000 25,000,000 25,000,000  
Amortized Cost [11],[27]               $ 0              
Fair Value [1],[11],[27]               $ 0              
Investment, Identifier [Axis]: Circana Group (f.k.a. NPD Group), Consumer Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base Rate Floor [6],[7] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [7],[13] $ 100,000                            
Amortized Cost [7] 100,000                            
Fair Value [4],[7] $ (100,000)                            
Investment, Identifier [Axis]: Circana Group (f.k.a. NPD Group), Consumer Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[41] 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50%                
Rate, PIK [6],[7],[41] 2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80%                
Rate, Max PIK [6],[7],[41] 2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80%                
Base Rate Floor [6],[7],[41] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [7],[13],[41] $ 19,200,000                            
Amortized Cost [7],[41] 19,200,000                            
Fair Value [4],[7],[41] $ (19,500,000)                            
Investment, Identifier [Axis]: Circana Group (f.k.a. NPD Group), Consumer Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base Rate Floor [6],[19] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[19] $ 900,000                            
Amortized Cost [19] 900,000                            
Fair Value [4],[19] $ (900,000)                            
Investment, Identifier [Axis]: Cision Ltd, Software & Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount $ 3,800,000             $ 3,800,000              
Amortized Cost 3,400,000             3,400,000              
Fair Value $ (2,500,000)             $ (2,400,000)              
Investment, Identifier [Axis]: Clarience Technologies LLC, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[7],[15],[16],[20],[36],[41] 6.25% [6],[7],[15],[16],[20],[36],[41] 6.25% [6],[7],[15],[16],[20],[36],[41] 6.25% [6],[7],[15],[16],[20],[36],[41] 6.25% [6],[7],[15],[16],[20],[36],[41] 6.25% [6],[7],[15],[16],[20],[36],[41] 6.25% [6],[7],[15],[16],[20],[36],[41] 6.25% [8],[9],[11],[12],[22],[37],[42] 6.25% [8],[9],[11],[12],[22],[37],[42] 6.25% [8],[9],[11],[12],[22],[37],[42] 6.25% [8],[9],[11],[12],[22],[37],[42] 6.25% [8],[9],[11],[12],[22],[37],[42] 6.25% [8],[9],[11],[12],[22],[37],[42] 6.25% [8],[9],[11],[12],[22],[37],[42]  
Base Rate Floor 1.00% [6],[7],[15],[16],[20],[36],[41] 1.00% [6],[7],[15],[16],[20],[36],[41] 1.00% [6],[7],[15],[16],[20],[36],[41] 1.00% [6],[7],[15],[16],[20],[36],[41] 1.00% [6],[7],[15],[16],[20],[36],[41] 1.00% [6],[7],[15],[16],[20],[36],[41] 1.00% [6],[7],[15],[16],[20],[36],[41] 1.00% [9],[11],[12],[22],[37],[42] 1.00% [9],[11],[12],[22],[37],[42] 1.00% [9],[11],[12],[22],[37],[42] 1.00% [9],[11],[12],[22],[37],[42] 1.00% [9],[11],[12],[22],[37],[42] 1.00% [9],[11],[12],[22],[37],[42] 1.00% [9],[11],[12],[22],[37],[42]  
Principal amount $ 293,200,000 [7],[13],[15],[16],[20],[36],[41]             $ 294,000,000.0 [9],[11],[12],[14],[22],[37],[42]              
Amortized Cost 284,300,000 [7],[15],[16],[20],[36],[41]             284,600,000 [9],[11],[12],[22],[37],[42]              
Fair Value $ (287,700,000) [4],[7],[15],[16],[20],[36],[41]             $ (287,900,000) [1],[9],[11],[12],[22],[37],[42]              
Investment, Identifier [Axis]: Clarience Technologies LLC, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 25,400,000 [13],[19]             $ 25,400,000 [14],[18]              
Amortized Cost 25,300,000 [19]             25,300,000 [18]              
Fair Value $ (25,000,000.0) [4],[19]             $ (24,900,000) [1],[18]              
Investment, Identifier [Axis]: ClubCorp Club Operations Inc, Consumer Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 2.75% 2.75% 2.75% 2.75% 2.75% 2.75% 2.75% 2.75% 2.75% 2.75% 2.75% 2.75% 2.75% 2.75%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount $ 31,900,000             $ 31,900,000              
Amortized Cost 29,900,000             29,900,000              
Fair Value $ (30,500,000)             $ (28,900,000)              
Investment, Identifier [Axis]: Community Brands Inc, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 32,600,000 [7],[13]             $ 32,700,000 [11],[14]              
Amortized Cost 32,100,000 [7]             32,100,000 [11]              
Fair Value $ (31,500,000) [4],[7]             $ (31,600,000) [1],[11]              
Investment, Identifier [Axis]: Community Brands Inc, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 3,900,000 [13],[19]             $ 3,900,000 [14],[18]              
Amortized Cost 3,800,000 [19]             3,800,000 [18]              
Fair Value $ (3,700,000) [4],[19]             $ (3,700,000) [1],[18]              
Investment, Identifier [Axis]: Community Brands Inc, Software & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 1,900,000 [13],[19]             $ 1,900,000 [14],[18]              
Amortized Cost 1,900,000 [19]             1,900,000 [18]              
Fair Value $ (1,900,000) [4],[19]             $ (1,900,000) [1],[18]              
Investment, Identifier [Axis]: Connecticut Avenue Securities Trust 2022-R08, Structured Mezzanine, Real Estate | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate               5.60% 5.60% 5.60% 5.60% 5.60% 5.60% 5.60%  
Base Rate Floor               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount               $ 2,300,000              
Amortized Cost               2,300,000              
Fair Value               (2,400,000)              
Investment, Identifier [Axis]: Connecticut Avenue Securities Trust 2022-R08, Structured Mezzanine, Real Estate Management & Development | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.60% 5.60% 5.60% 5.60% 5.60% 5.60% 5.60%                
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount $ 2,300,000                            
Amortized Cost 2,300,000                            
Fair Value (2,400,000)                            
Investment, Identifier [Axis]: Constellis Holdings LLC , Senior Secured Loans—Second Lien                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               (13,500,000)             (12,000,000.0)
Investment, Identifier [Axis]: Constellis Holdings LLC 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value (15,000,000.0)             (15,000,000.0)              
Investment, Identifier [Axis]: Constellis Holdings LLC 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (13,500,000)             $ (13,500,000)              
Investment, Identifier [Axis]: Constellis Holdings LLC, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.50% [6],[7],[43] 7.50% [6],[7],[43] 7.50% [6],[7],[43] 7.50% [6],[7],[43] 7.50% [6],[7],[43] 7.50% [6],[7],[43] 7.50% [6],[7],[43] 7.50% [8],[11],[44] 7.50% [8],[11],[44] 7.50% [8],[11],[44] 7.50% [8],[11],[44] 7.50% [8],[11],[44] 7.50% [8],[11],[44] 7.50% [8],[11],[44]  
Base Rate Floor 1.00% [6],[7],[43] 1.00% [6],[7],[43] 1.00% [6],[7],[43] 1.00% [6],[7],[43] 1.00% [6],[7],[43] 1.00% [6],[7],[43] 1.00% [6],[7],[43] 1.00% [11],[44] 1.00% [11],[44] 1.00% [11],[44] 1.00% [11],[44] 1.00% [11],[44] 1.00% [11],[44] 1.00% [11],[44]  
Principal amount $ 15,000,000.0 [7],[13],[43]             $ 15,000,000.0 [11],[14],[44]              
Amortized Cost 14,500,000 [7],[43]             14,400,000 [11],[44]              
Fair Value $ (15,000,000.0) [4],[7],[43]             $ (15,000,000.0) [1],[11],[44]              
Investment, Identifier [Axis]: Constellis Holdings LLC, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 11.00% [6],[7],[43] 11.00% [6],[7],[43] 11.00% [6],[7],[43] 11.00% [6],[7],[43] 11.00% [6],[7],[43] 11.00% [6],[7],[43] 11.00% [6],[7],[43] 11.00% [8],[11],[44] 11.00% [8],[11],[44] 11.00% [8],[11],[44] 11.00% [8],[11],[44] 11.00% [8],[11],[44] 11.00% [8],[11],[44] 11.00% [8],[11],[44]  
Rate, PIK 0.00% [6],[7],[43] 0.00% [6],[7],[43] 0.00% [6],[7],[43] 0.00% [6],[7],[43] 0.00% [6],[7],[43] 0.00% [6],[7],[43] 0.00% [6],[7],[43] 0.00% [8],[11],[44] 0.00% [8],[11],[44] 0.00% [8],[11],[44] 0.00% [8],[11],[44] 0.00% [8],[11],[44] 0.00% [8],[11],[44] 0.00% [8],[11],[44]  
Rate, Max PIK 5.00% [6],[7],[43] 5.00% [6],[7],[43] 5.00% [6],[7],[43] 5.00% [6],[7],[43] 5.00% [6],[7],[43] 5.00% [6],[7],[43] 5.00% [6],[7],[43] 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Base Rate Floor 1.00% [6],[7],[43] 1.00% [6],[7],[43] 1.00% [6],[7],[43] 1.00% [6],[7],[43] 1.00% [6],[7],[43] 1.00% [6],[7],[43] 1.00% [6],[7],[43] 1.00% [11],[44] 1.00% [11],[44] 1.00% [11],[44] 1.00% [11],[44] 1.00% [11],[44] 1.00% [11],[44] 1.00% [11],[44]  
Principal amount $ 13,500,000 [7],[13],[43]             $ 13,500,000 [11],[14],[44]              
Amortized Cost 12,800,000 [7],[43]             12,800,000 [11],[44]              
Fair Value (13,500,000) [4],[7],[43]             (13,500,000) [1],[11],[44]              
Investment, Identifier [Axis]: Constellis Holdings LLC, Private Equity                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (3,900,000)             $ (6,300,000)              
Investment, Identifier [Axis]: Constellis Holdings LLC, Private Equity, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 849,702 [7],[20],[32],[43] 849,702 [7],[20],[32],[43] 849,702 [7],[20],[32],[43] 849,702 [7],[20],[32],[43] 849,702 [7],[20],[32],[43] 849,702 [7],[20],[32],[43] 849,702 [7],[20],[32],[43] 849,702 [11],[22],[27],[44] 849,702 [11],[22],[27],[44] 849,702 [11],[22],[27],[44] 849,702 [11],[22],[27],[44] 849,702 [11],[22],[27],[44] 849,702 [11],[22],[27],[44] 849,702 [11],[22],[27],[44]  
Amortized Cost $ 10,300,000 [7],[20],[32],[43]             $ 10,300,000 [11],[22],[27],[44]              
Fair Value $ (3,900,000) [4],[7],[20],[32],[43]             (6,300,000) [1],[11],[22],[27],[44]              
Investment, Identifier [Axis]: Constellis Holdings LLC, Private Equity, Equity/Other                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               (6,300,000)             (200,000)
Investment, Identifier [Axis]: Constellis Holdings LLC, Senior Secured Loans—First Lien -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ (15,000,000.0)             (15,000,000.0)
Investment, Identifier [Axis]: Corsearch Intermediate Inc, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[7],[41] 5.50% [6],[7],[41] 5.50% [6],[7],[41] 5.50% [6],[7],[41] 5.50% [6],[7],[41] 5.50% [6],[7],[41] 5.50% [6],[7],[41] 5.50% [8],[11],[42] 5.50% [8],[11],[42] 5.50% [8],[11],[42] 5.50% [8],[11],[42] 5.50% [8],[11],[42] 5.50% [8],[11],[42] 5.50% [8],[11],[42]  
Base Rate Floor 1.00% [6],[7],[41] 1.00% [6],[7],[41] 1.00% [6],[7],[41] 1.00% [6],[7],[41] 1.00% [6],[7],[41] 1.00% [6],[7],[41] 1.00% [6],[7],[41] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42]  
Principal amount $ 30,100,000 [7],[13],[41]             $ 30,100,000 [11],[14],[42]              
Amortized Cost 28,600,000 [7],[41]             28,500,000 [11],[42]              
Fair Value $ (29,900,000) [4],[7],[41]             $ (29,800,000) [1],[11],[42]              
Investment, Identifier [Axis]: Corsearch Intermediate Inc, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 4,400,000 [13],[19]             $ 4,400,000 [14],[18]              
Amortized Cost 4,400,000 [19]             4,400,000 [18]              
Fair Value $ (4,400,000) [4],[19]             $ (4,400,000) [1],[18]              
Investment, Identifier [Axis]: Covis Finco Sarl, Pharmaceuticals, Biotechnology & Life Sciences                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [19],[33] 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%                
Base Rate Floor [19],[33] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [19],[33] $ 20,000,000.0                            
Amortized Cost [19],[33] 20,000,000.0                            
Fair Value [19],[33] $ (20,000,000.0)                            
Investment, Identifier [Axis]: Creation Technologies Inc, Technology Hardware & Equipment | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base Rate Floor 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount $ 2,300,000             $ 2,300,000              
Amortized Cost 2,100,000             2,100,000              
Fair Value (2,000,000.0)             (1,800,000)              
Investment, Identifier [Axis]: Credit Opportunities Partners JV, LLC 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value (1,396,600,000)             (1,428,300,000)             (1,396,200,000)
Investment, Identifier [Axis]: Credit Opportunities Partners JV, LLC, Diversified Financials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [11],[14],[28],[35]               1,637,300,000              
Amortized Cost [11],[28],[35]               1,571,700,000              
Fair Value [1],[11],[28],[35]               $ (1,428,300,000)              
Investment, Identifier [Axis]: Credit Opportunities Partners JV, LLC, Financial Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [7],[13],[33],[34] 1,637,300,000                            
Amortized Cost [7],[33],[34] 1,571,700,000                            
Fair Value [7],[33],[34] $ (1,396,600,000)                            
Investment, Identifier [Axis]: Cubic Corp, Preferred Stock, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 11.00% [6],[7] 11.00% [6],[7] 11.00% [6],[7] 11.00% [6],[7] 11.00% [6],[7] 11.00% [6],[7] 11.00% [6],[7] 11.00% [8],[11] 11.00% [8],[11] 11.00% [8],[11] 11.00% [8],[11] 11.00% [8],[11] 11.00% [8],[11] 11.00% [8],[11]  
Rate, Max PIK 11.00% [6],[7] 11.00% [6],[7] 11.00% [6],[7] 11.00% [6],[7] 11.00% [6],[7] 11.00% [6],[7] 11.00% [6],[7] 11.00% [8],[11] 11.00% [8],[11] 11.00% [8],[11] 11.00% [8],[11] 11.00% [8],[11] 11.00% [8],[11] 11.00% [8],[11]  
Number of Shares | shares 42,141,600 [7] 42,141,600 [7] 42,141,600 [7] 42,141,600 [7] 42,141,600 [7] 42,141,600 [7] 42,141,600 [7] 42,141,600 [11] 42,141,600 [11] 42,141,600 [11] 42,141,600 [11] 42,141,600 [11] 42,141,600 [11] 42,141,600 [11]  
Amortized Cost $ 39,700,000 [7]             $ 39,800,000 [11]              
Fair Value $ (33,300,000) [4],[7]             $ (34,700,000) [1],[11]              
Investment, Identifier [Axis]: Cubic Corp, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.63% [6],[7] 7.63% [6],[7] 7.63% [6],[7] 7.63% [6],[7] 7.63% [6],[7] 7.63% [6],[7] 7.63% [6],[7] 7.63% [8],[11] 7.63% [8],[11] 7.63% [8],[11] 7.63% [8],[11] 7.63% [8],[11] 7.63% [8],[11] 7.63% [8],[11]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 44,800,000 [7],[13]             $ 44,800,000 [11],[14]              
Amortized Cost 42,200,000 [7]             42,200,000 [11]              
Fair Value $ (40,400,000) [4],[7]             $ (40,600,000) [1],[11]              
Investment, Identifier [Axis]: Cubic Corp, Software & Services 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 4.25% 4.25% 4.25% 4.25% 4.25% 4.25% 4.25% 4.25% 4.25% 4.25% 4.25% 4.25% 4.25% 4.25%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 9,000,000.0             $ 9,100,000              
Amortized Cost 9,100,000             9,100,000              
Fair Value $ (7,800,000)             $ (7,700,000)              
Investment, Identifier [Axis]: Cubic Corp, Software & Services 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.63% 7.63% 7.63% 7.63% 7.63% 7.63% 7.63% 7.63% 7.63% 7.63% 7.63% 7.63% 7.63% 7.63%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 10,000,000.0             $ 10,000,000.0              
Amortized Cost 9,700,000             9,700,000              
Fair Value $ (9,000,000.0)             $ (9,100,000)              
Investment, Identifier [Axis]: DOC Generici Srl, Pharmaceuticals, Biotechnology & Life Sciences 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[7],[33] 6.50% [6],[7],[33] 6.50% [6],[7],[33] 6.50% [6],[7],[33] 6.50% [6],[7],[33] 6.50% [6],[7],[33] 6.50% [6],[7],[33] 6.50% [8],[11],[28] 6.50% [8],[11],[28] 6.50% [8],[11],[28] 6.50% [8],[11],[28] 6.50% [8],[11],[28] 6.50% [8],[11],[28] 6.50% [8],[11],[28]  
Base Rate Floor 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28]  
Principal amount | €       € 23.1 [7],[13],[33]             € 23.1 [11],[14],[28]        
Amortized Cost $ 22,500,000 [7],[33]             $ 22,500,000 [11],[28]              
Fair Value $ (24,600,000) [4],[7],[33]             $ (24,100,000) [1],[11],[28]              
Investment, Identifier [Axis]: DOC Generici Srl, Pharmaceuticals, Biotechnology & Life Sciences 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[7],[33] 6.50% [6],[7],[33] 6.50% [6],[7],[33] 6.50% [6],[7],[33] 6.50% [6],[7],[33] 6.50% [6],[7],[33] 6.50% [6],[7],[33] 6.50% [8],[18],[28] 6.50% [8],[18],[28] 6.50% [8],[18],[28] 6.50% [8],[18],[28] 6.50% [8],[18],[28] 6.50% [8],[18],[28] 6.50% [8],[18],[28]  
Base Rate Floor 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [18],[28] 0.00% [18],[28] 0.00% [18],[28] 0.00% [18],[28] 0.00% [18],[28] 0.00% [18],[28] 0.00% [18],[28]  
Principal amount | €       € 0.1 [7],[13],[33]             € 2.4 [14],[18],[28]        
Amortized Cost $ 0 [7],[33]             $ 2,300,000 [18],[28]              
Fair Value $ (100,000) [4],[7],[33]             $ (2,200,000) [1],[18],[28]              
Investment, Identifier [Axis]: DOC Generici Srl, Pharmaceuticals, Biotechnology & Life Sciences 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[18],[28] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base Rate Floor [6],[18],[28] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | € [13],[18],[28]       € 2.3                      
Amortized Cost [18],[28] $ 2,300,000                            
Fair Value [4],[18],[28] $ (2,200,000)                            
Investment, Identifier [Axis]: Dental Care Alliance Inc, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[16],[20],[21],[41] 6.41% 6.41% 6.41% 6.41% 6.41% 6.41% 6.41%                
Base Rate Floor [6],[7],[16],[20],[21],[41] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [7],[13],[16],[20],[21],[41] $ 136,800,000                            
Amortized Cost [7],[16],[20],[21],[41] 133,200,000                            
Fair Value [4],[7],[16],[20],[21],[41] $ (134,500,000)                            
Investment, Identifier [Axis]: Dental Care Alliance Inc, Health Care Equipment & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[9],[11],[22],[23],[42]               6.41% 6.41% 6.41% 6.41% 6.41% 6.41% 6.41%  
Base Rate Floor [9],[11],[22],[23],[42]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [9],[11],[14],[22],[23],[42]               $ 135,400,000              
Amortized Cost [9],[11],[22],[23],[42]               131,700,000              
Fair Value [1],[9],[11],[22],[23],[42]               $ (132,700,000)              
Investment, Identifier [Axis]: Dental Care Alliance Inc, Health Care Equipment & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[18]               6.41% 6.41% 6.41% 6.41% 6.41% 6.41% 6.41%  
Base Rate Floor [18]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [14],[18]               $ 1,700,000              
Amortized Cost [18]               1,700,000              
Fair Value [1],[18]               $ (1,600,000)              
Investment, Identifier [Axis]: EIF Van Hook Holdings LLC, Energy | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate               5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%  
Base Rate Floor               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount               $ 7,200,000              
Amortized Cost               7,000,000.0              
Fair Value               $ (7,000,000.0)              
Investment, Identifier [Axis]: EaglePicher Technologies LLC, Capital Goods | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount $ 400,000             $ 400,000              
Amortized Cost 400,000             400,000              
Fair Value $ (300,000)             $ (200,000)              
Investment, Identifier [Axis]: Element Materials Technology Group US Holdings Inc, Commercial & Professional Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25%  
Base Rate Floor 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount | £         £ 21.0             £ 21.0      
Amortized Cost $ 23,000,000.0             $ 23,000,000.0              
Fair Value $ (25,700,000)             $ (24,700,000)              
Investment, Identifier [Axis]: Element Materials Technology Group US Holdings Inc, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 4.25% [6],[7],[39],[41] 4.25% [6],[7],[39],[41] 4.25% [6],[7],[39],[41] 4.25% [6],[7],[39],[41] 4.25% [6],[7],[39],[41] 4.25% [6],[7],[39],[41] 4.25% [6],[7],[39],[41] 4.25% [8],[11],[28],[40] 4.25% [8],[11],[28],[40] 4.25% [8],[11],[28],[40] 4.25% [8],[11],[28],[40] 4.25% [8],[11],[28],[40] 4.25% [8],[11],[28],[40] 4.25% [8],[11],[28],[40]  
Base Rate Floor 0.50% [6],[7],[39],[41] 0.50% [6],[7],[39],[41] 0.50% [6],[7],[39],[41] 0.50% [6],[7],[39],[41] 0.50% [6],[7],[39],[41] 0.50% [6],[7],[39],[41] 0.50% [6],[7],[39],[41] 0.00% [11],[28],[40] 0.00% [11],[28],[40] 0.00% [11],[28],[40] 0.00% [11],[28],[40] 0.00% [11],[28],[40] 0.00% [11],[28],[40] 0.00% [11],[28],[40]  
Principal amount $ 1,400,000 [7],[13],[39],[41]                   € 0.3 [11],[14],[28],[40]        
Amortized Cost 1,400,000 [7],[39],[41]             $ 400,000 [11],[28],[40]              
Fair Value $ (1,400,000) [4],[7],[39],[41]             $ (400,000) [1],[11],[28],[40]              
Investment, Identifier [Axis]: Element Materials Technology Group US Holdings Inc, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 4.25% [6],[7],[33],[39] 4.25% [6],[7],[33],[39] 4.25% [6],[7],[33],[39] 4.25% [6],[7],[33],[39] 4.25% [6],[7],[33],[39] 4.25% [6],[7],[33],[39] 4.25% [6],[7],[33],[39] 4.25% [8],[11],[28],[40] 4.25% [8],[11],[28],[40] 4.25% [8],[11],[28],[40] 4.25% [8],[11],[28],[40] 4.25% [8],[11],[28],[40] 4.25% [8],[11],[28],[40] 4.25% [8],[11],[28],[40]  
Base Rate Floor 0.00% [6],[7],[33],[39] 0.00% [6],[7],[33],[39] 0.00% [6],[7],[33],[39] 0.00% [6],[7],[33],[39] 0.00% [6],[7],[33],[39] 0.00% [6],[7],[33],[39] 0.00% [6],[7],[33],[39] 0.50% [11],[28],[40] 0.50% [11],[28],[40] 0.50% [11],[28],[40] 0.50% [11],[28],[40] 0.50% [11],[28],[40] 0.50% [11],[28],[40] 0.50% [11],[28],[40]  
Principal amount       € 0.3 [7],[13],[33],[39]       $ 1,400,000 [11],[14],[28],[40]              
Amortized Cost $ 400,000 [7],[33],[39]             1,400,000 [11],[28],[40]              
Fair Value $ (400,000) [4],[7],[33],[39]             $ (1,400,000) [1],[11],[28],[40]              
Investment, Identifier [Axis]: Element Materials Technology Group US Holdings Inc, Commercial & Professional Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 8.50% [7],[33] 8.50% [7],[33] 8.50% [7],[33] 8.50% [7],[33] 8.50% [7],[33] 8.50% [7],[33] 8.50% [7],[33] 8.50% [8],[11],[28] 8.50% [8],[11],[28] 8.50% [8],[11],[28] 8.50% [8],[11],[28] 8.50% [8],[11],[28] 8.50% [8],[11],[28] 8.50% [8],[11],[28]  
Rate, Max PIK 8.50% [7],[33] 8.50% [7],[33] 8.50% [7],[33] 8.50% [7],[33] 8.50% [7],[33] 8.50% [7],[33] 8.50% [7],[33] 8.50% [8],[11],[28] 8.50% [8],[11],[28] 8.50% [8],[11],[28] 8.50% [8],[11],[28] 8.50% [8],[11],[28] 8.50% [8],[11],[28] 8.50% [8],[11],[28]  
Base Rate Floor 0.50% [7],[33] 0.50% [7],[33] 0.50% [7],[33] 0.50% [7],[33] 0.50% [7],[33] 0.50% [7],[33] 0.50% [7],[33] 0.50% [11],[28] 0.50% [11],[28] 0.50% [11],[28] 0.50% [11],[28] 0.50% [11],[28] 0.50% [11],[28] 0.50% [11],[28]  
Principal amount $ 70,100,000 [7],[33]             $ 67,900,000 [11],[14],[28]              
Amortized Cost 68,700,000 [7],[33]             66,500,000 [11],[28]              
Fair Value $ (67,300,000) [7],[33]             $ (64,600,000) [1],[11],[28]              
Investment, Identifier [Axis]: Ellucian Inc, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 8.00% [6],[7] 8.00% [6],[7] 8.00% [6],[7] 8.00% [6],[7] 8.00% [6],[7] 8.00% [6],[7] 8.00% [6],[7] 8.00% [8],[11] 8.00% [8],[11] 8.00% [8],[11] 8.00% [8],[11] 8.00% [8],[11] 8.00% [8],[11] 8.00% [8],[11]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Principal amount $ 179,200,000 [7],[13]             $ 179,200,000 [11],[14]              
Amortized Cost 171,300,000 [7]             170,900,000 [11]              
Fair Value $ (181,100,000) [4],[7]             $ (177,500,000) [1],[11]              
Investment, Identifier [Axis]: Emerald Expositions Holding Inc, Media & Entertainment | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount $ 1,400,000             $ 1,400,000              
Amortized Cost 1,300,000             1,300,000              
Fair Value $ (1,400,000)             $ (1,400,000)              
Investment, Identifier [Axis]: Encora Digital Inc, Commercial & Professional Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Rate, PIK 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Rate, Max PIK 2.40% 2.40% 2.40% 2.40% 2.40% 2.40% 2.40%                
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount $ 16,300,000                            
Amortized Cost 15,900,000                            
Fair Value $ (15,600,000)                            
Investment, Identifier [Axis]: Encora Digital Inc, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base Rate Floor [6],[7] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [7],[13] $ 19,600,000                            
Amortized Cost [7] 19,300,000                            
Fair Value [4],[7] $ (18,900,000)                            
Investment, Identifier [Axis]: Encora Digital Inc, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Rate, PIK [6],[7] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Rate, Max PIK [6],[7] 2.40% 2.40% 2.40% 2.40% 2.40% 2.40% 2.40%                
Base Rate Floor [6],[7] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [7],[13] $ 65,100,000                            
Amortized Cost [7] 64,000,000.0                            
Fair Value [4],[7] $ (62,600,000)                            
Investment, Identifier [Axis]: Encora Digital Inc, Commercial & Professional Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK [7] 9.80% 9.80% 9.80% 9.80% 9.80% 9.80% 9.80%                
Rate, Max PIK [7] 9.80% 9.80% 9.80% 9.80% 9.80% 9.80% 9.80%                
Principal amount [7] $ 23,800,000                            
Amortized Cost [7] 23,200,000                            
Fair Value [7] $ (22,600,000)                            
Investment, Identifier [Axis]: Encora Digital Inc, Software & Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Rate, PIK               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Rate, Max PIK               2.40% 2.40% 2.40% 2.40% 2.40% 2.40% 2.40%  
Base Rate Floor               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount               $ 16,300,000              
Amortized Cost               15,900,000              
Fair Value               $ (15,400,000)              
Investment, Identifier [Axis]: Encora Digital Inc, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Rate, PIK [8],[11]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Rate, Max PIK [8],[11]               2.40% 2.40% 2.40% 2.40% 2.40% 2.40% 2.40%  
Base Rate Floor [11]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [11],[14]               $ 65,100,000              
Amortized Cost [11]               63,900,000              
Fair Value [1],[11]               $ (61,700,000)              
Investment, Identifier [Axis]: Encora Digital Inc, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[18]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base Rate Floor [18]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [14],[18]               $ 19,600,000              
Amortized Cost [18]               19,400,000              
Fair Value [1],[18]               $ (18,600,000)              
Investment, Identifier [Axis]: Encora Digital Inc, Software & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK [8],[11]               9.80% 9.80% 9.80% 9.80% 9.80% 9.80% 9.80%  
Rate, Max PIK [8],[11]               9.80% 9.80% 9.80% 9.80% 9.80% 9.80% 9.80%  
Principal amount [11],[14]               $ 23,800,000              
Amortized Cost [11]               23,200,000              
Fair Value [1],[11]               $ (22,600,000)              
Investment, Identifier [Axis]: Envigo Laboratories Inc, Series A Warrant, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [27],[37]               10,924 10,924 10,924 10,924 10,924 10,924 10,924  
Amortized Cost [27],[37]               $ 0              
Fair Value [1],[27],[37]               $ 0              
Investment, Identifier [Axis]: Envigo Laboratories Inc, Series B Warrant, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [27],[37]               17,515 17,515 17,515 17,515 17,515 17,515 17,515  
Amortized Cost [27],[37]               $ 0              
Fair Value [1],[27],[37]               $ 0              
Investment, Identifier [Axis]: Envirotainer Ltd, Transportation                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [18],[28] 6.00% [6] 6.00% [6] 6.00% [6] 6.00% [6] 6.00% [6] 6.00% [6] 6.00% [6] 6.00% [8] 6.00% [8] 6.00% [8] 6.00% [8] 6.00% [8] 6.00% [8] 6.00% [8]  
Rate, PIK [18],[28] 0.00% [6] 0.00% [6] 0.00% [6] 0.00% [6] 0.00% [6] 0.00% [6] 0.00% [6] 0.00% [8] 0.00% [8] 0.00% [8] 0.00% [8] 0.00% [8] 0.00% [8] 0.00% [8]  
Rate, Max PIK [18],[28] 3.00% [6] 3.00% [6] 3.00% [6] 3.00% [6] 3.00% [6] 3.00% [6] 3.00% [6] 3.00% [8] 3.00% [8] 3.00% [8] 3.00% [8] 3.00% [8] 3.00% [8] 3.00% [8]  
Base Rate Floor [18],[28] 0.00% [6] 0.00% [6] 0.00% [6] 0.00% [6] 0.00% [6] 0.00% [6] 0.00% [6] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | € [18],[28]       € 2.7 [13]             € 2.7 [14]        
Amortized Cost [18],[28] $ 2,700,000             $ 2,700,000              
Fair Value [18],[28] $ (2,700,000) [4]             $ (2,600,000) [1]              
Investment, Identifier [Axis]: Envirotainer Ltd, Transportation 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Rate, PIK 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Rate, Max PIK 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | €       € 14.9             € 14.9        
Amortized Cost $ 13,900,000             $ 13,900,000              
Fair Value $ (15,800,000)             $ (15,100,000)              
Investment, Identifier [Axis]: Envirotainer Ltd, Transportation 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Rate, PIK 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Rate, Max PIK 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 7,600,000             $ 7,600,000              
Amortized Cost 7,400,000             7,400,000              
Fair Value $ (7,400,000)             $ (7,300,000)              
Investment, Identifier [Axis]: Excelitas Technologies Corp, Technology Hardware & Equipment 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 900,000 [7],[13]             $ 1,300,000 [11],[14]              
Amortized Cost 900,000 [7]             1,300,000 [11]              
Fair Value $ (900,000) [4],[7]             $ (1,300,000) [1],[11]              
Investment, Identifier [Axis]: Excelitas Technologies Corp, Technology Hardware & Equipment 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | €       € 4.1             € 4.1        
Amortized Cost $ 4,200,000             $ 4,200,000              
Fair Value $ (4,300,000)             $ (4,200,000)              
Investment, Identifier [Axis]: Excelitas Technologies Corp, Technology Hardware & Equipment 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 1,700,000 [7],[13]             $ 1,000,000.0 [14],[18]              
Amortized Cost 1,700,000 [7]             1,000,000.0 [18]              
Fair Value $ (1,600,000) [4],[7]             $ (1,000,000.0) [1],[18]              
Investment, Identifier [Axis]: Excelitas Technologies Corp, Technology Hardware & Equipment 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 24,500,000             $ 24,500,000              
Amortized Cost 24,300,000             24,300,000              
Fair Value $ (24,100,000)             $ (23,900,000)              
Investment, Identifier [Axis]: Excelitas Technologies Corp, Technology Hardware & Equipment 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 1,400,000 [13],[19]             $ 4,700,000 [14],[18]              
Amortized Cost 1,400,000 [19]             4,700,000 [18]              
Fair Value $ (1,400,000) [4],[19]             (4,600,000) [1],[18]              
Investment, Identifier [Axis]: Excelitas Technologies Corp, Technology Hardware & Equipment 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base Rate Floor [6],[19] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[19] $ 3,100,000                            
Amortized Cost [19] 3,100,000                            
Fair Value [4],[19] $ (3,000,000.0)                            
Investment, Identifier [Axis]: Fairway Group Holdings Corp 2, Senior Secured Loans—First Lien -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               0             0
Investment, Identifier [Axis]: Fairway Group Holdings Corp, Common Stock, Equity/Other                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               0             0
Investment, Identifier [Axis]: Fairway Group Holdings Corp, Senior Secured Loans—First Lien -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ 0             (700,000)
Investment, Identifier [Axis]: Follett Software Co, Software & Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 37,400,000             $ 37,500,000              
Amortized Cost 37,100,000             37,200,000              
Fair Value $ (36,900,000)             $ (36,700,000)              
Investment, Identifier [Axis]: Follett Software Co, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[16],[17],[20],[21] 5.75% [6],[16],[17],[20],[21] 5.75% [6],[16],[17],[20],[21] 5.75% [6],[16],[17],[20],[21] 5.75% [6],[16],[17],[20],[21] 5.75% [6],[16],[17],[20],[21] 5.75% [6],[16],[17],[20],[21] 5.75% [8],[9],[10],[22],[23] 5.75% [8],[9],[10],[22],[23] 5.75% [8],[9],[10],[22],[23] 5.75% [8],[9],[10],[22],[23] 5.75% [8],[9],[10],[22],[23] 5.75% [8],[9],[10],[22],[23] 5.75% [8],[9],[10],[22],[23]  
Base Rate Floor 0.80% [6],[16],[17],[20],[21] 0.80% [6],[16],[17],[20],[21] 0.80% [6],[16],[17],[20],[21] 0.80% [6],[16],[17],[20],[21] 0.80% [6],[16],[17],[20],[21] 0.80% [6],[16],[17],[20],[21] 0.80% [6],[16],[17],[20],[21] 0.80% [9],[10],[22],[23] 0.80% [9],[10],[22],[23] 0.80% [9],[10],[22],[23] 0.80% [9],[10],[22],[23] 0.80% [9],[10],[22],[23] 0.80% [9],[10],[22],[23] 0.80% [9],[10],[22],[23]  
Principal amount $ 73,500,000 [13],[16],[17],[20],[21]             $ 73,700,000 [9],[10],[14],[22],[23]              
Amortized Cost 72,900,000 [16],[17],[20],[21]             73,100,000 [9],[10],[22],[23]              
Fair Value $ (72,500,000) [4],[16],[17],[20],[21]             $ (72,100,000) [1],[9],[10],[22],[23]              
Investment, Identifier [Axis]: Follett Software Co, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 9,900,000 [13],[19]             $ 9,900,000 [14],[18]              
Amortized Cost 9,900,000 [19]             9,900,000 [18]              
Fair Value $ (9,700,000) [4],[19]             $ (9,700,000) [1],[18]              
Investment, Identifier [Axis]: Foundation Consumer Brands LLC, Pharmaceuticals, Biotechnology & Life Sciences 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[7],[20],[41] 5.50% [6],[7],[20],[41] 5.50% [6],[7],[20],[41] 5.50% [6],[7],[20],[41] 5.50% [6],[7],[20],[41] 5.50% [6],[7],[20],[41] 5.50% [6],[7],[20],[41] 5.50% [8],[11],[22],[42] 5.50% [8],[11],[22],[42] 5.50% [8],[11],[22],[42] 5.50% [8],[11],[22],[42] 5.50% [8],[11],[22],[42] 5.50% [8],[11],[22],[42] 5.50% [8],[11],[22],[42]  
Base Rate Floor 1.00% [6],[7],[20],[41] 1.00% [6],[7],[20],[41] 1.00% [6],[7],[20],[41] 1.00% [6],[7],[20],[41] 1.00% [6],[7],[20],[41] 1.00% [6],[7],[20],[41] 1.00% [6],[7],[20],[41] 1.00% [11],[22],[42] 1.00% [11],[22],[42] 1.00% [11],[22],[42] 1.00% [11],[22],[42] 1.00% [11],[22],[42] 1.00% [11],[22],[42] 1.00% [11],[22],[42]  
Principal amount $ 81,500,000 [7],[13],[20],[41]             $ 83,900,000 [11],[14],[22],[42]              
Amortized Cost 78,200,000 [7],[20],[41]             80,500,000 [11],[22],[42]              
Fair Value $ (82,300,000) [4],[7],[20],[41]             $ (84,700,000) [1],[11],[22],[42]              
Investment, Identifier [Axis]: Foundation Consumer Brands LLC, Pharmaceuticals, Biotechnology & Life Sciences 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 6,600,000 [13],[19]             $ 6,600,000 [14],[18]              
Amortized Cost 6,600,000 [19]             6,600,000 [18]              
Fair Value $ (6,600,000) [4],[19]             $ (6,600,000) [1],[18]              
Investment, Identifier [Axis]: Foundation Risk Partners Corp, Insurance 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[7],[41] 6.00% [6],[7],[41] 6.00% [6],[7],[41] 6.00% [6],[7],[41] 6.00% [6],[7],[41] 6.00% [6],[7],[41] 6.00% [6],[7],[41] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11]  
Base Rate Floor 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 79,700,000 [7],[13],[41]             $ 2,900,000 [11],[14]              
Amortized Cost 78,600,000 [7],[41]             2,800,000 [11]              
Fair Value $ (77,300,000) [4],[7],[41]             $ (2,800,000) [1],[11]              
Investment, Identifier [Axis]: Foundation Risk Partners Corp, Insurance 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [8],[11],[42] 6.00% [8],[11],[42] 6.00% [8],[11],[42] 6.00% [8],[11],[42] 6.00% [8],[11],[42] 6.00% [8],[11],[42] 6.00% [8],[11],[42]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [11],[42] 0.80% [11],[42] 0.80% [11],[42] 0.80% [11],[42] 0.80% [11],[42] 0.80% [11],[42] 0.80% [11],[42]  
Principal amount $ 7,000,000.0 [13],[19]             $ 79,900,000 [11],[14],[42]              
Amortized Cost 6,900,000 [19]             78,800,000 [11],[42]              
Fair Value $ (6,800,000) [4],[19]             $ (78,100,000) [1],[11],[42]              
Investment, Identifier [Axis]: Foundation Risk Partners Corp, Insurance 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[18]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base Rate Floor [18]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [14],[18]               $ 4,100,000              
Amortized Cost [18]               4,100,000              
Fair Value [1],[18]               $ (4,000,000.0)              
Investment, Identifier [Axis]: Fox Head Inc, Common Stock, Consumer Durables & Apparel                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 10,000,000 [7],[55] 10,000,000 [7],[55] 10,000,000 [7],[55] 10,000,000 [7],[55] 10,000,000 [7],[55] 10,000,000 [7],[55] 10,000,000 [7],[55] 10,000,000 [11],[27] 10,000,000 [11],[27] 10,000,000 [11],[27] 10,000,000 [11],[27] 10,000,000 [11],[27] 10,000,000 [11],[27] 10,000,000 [11],[27]  
Amortized Cost $ 2,900,000 [7],[55]             $ 2,900,000 [11],[27]              
Fair Value 0 [4],[7],[55]             0 [1],[11],[27]              
Investment, Identifier [Axis]: Fronton BV, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (1,200,000)             $ (1,000,000.0)              
Investment, Identifier [Axis]: Fronton BV, Common Stock, Consumer Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 14,943 [32],[51] 14,943 [32],[51] 14,943 [32],[51] 14,943 [32],[51] 14,943 [32],[51] 14,943 [32],[51] 14,943 [32],[51] 14,943 [11],[27],[44] 14,943 [11],[27],[44] 14,943 [11],[27],[44] 14,943 [11],[27],[44] 14,943 [11],[27],[44] 14,943 [11],[27],[44] 14,943 [11],[27],[44]  
Amortized Cost $ 0 [32],[51]             $ 0 [11],[27],[44]              
Fair Value (1,200,000) [4],[32],[51]             $ (1,000,000.0) [1],[11],[27],[44]              
Investment, Identifier [Axis]: GA Capital Specialty Lending Fund, Limited Partnership Interest, Diversified Financials | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares               1,000,000 1,000,000 1,000,000 1,000,000 1,000,000 1,000,000 1,000,000  
Amortized Cost               $ 0              
Fair Value               $ (5,300,000)              
Investment, Identifier [Axis]: GA Capital Specialty Lending Fund, Limited Partnership Interest, Financial Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount 1,000,000.0                            
Amortized Cost 0                            
Fair Value $ (900,000)                            
Investment, Identifier [Axis]: Galaxy Universal LLC, Common Stock, Consumer Durables & Apparel                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 228,806 [32],[51] 228,806 [32],[51] 228,806 [32],[51] 228,806 [32],[51] 228,806 [32],[51] 228,806 [32],[51] 228,806 [32],[51] 228,806 [27],[52] 228,806 [27],[52] 228,806 [27],[52] 228,806 [27],[52] 228,806 [27],[52] 228,806 [27],[52] 228,806 [27],[52]  
Amortized Cost $ 35,500,000 [32],[51]             $ 35,400,000 [27],[52]              
Fair Value $ 0 [4],[32],[51]             $ (7,500,000) [1],[27],[52]              
Investment, Identifier [Axis]: Galaxy Universal LLC, Consumer Durables & Apparel | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 7,500,000             $ 8,800,000              
Amortized Cost 7,500,000             8,800,000              
Fair Value $ (7,200,000)             $ (8,700,000)              
Investment, Identifier [Axis]: Galaxy Universal LLC, Consumer Durables & Apparel 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Principal amount $ 7,500,000 [7],[13]             $ 7,500,000 [11],[14]              
Amortized Cost 7,500,000 [7]             7,500,000 [11]              
Fair Value $ (7,500,000) [4],[7]             $ (7,500,000) [1],[11]              
Investment, Identifier [Axis]: Galaxy Universal LLC, Consumer Durables & Apparel 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Principal amount $ 87,800,000 [7],[13]             $ 88,000,000.0 [11],[14]              
Amortized Cost 87,800,000 [7]             88,000,000.0 [11]              
Fair Value $ (84,600,000) [4],[7]             $ (85,300,000) [1],[11]              
Investment, Identifier [Axis]: Galaxy Universal LLC, Consumer Durables & Apparel 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.00% [6],[7] 5.00% [6],[7] 5.00% [6],[7] 5.00% [6],[7] 5.00% [6],[7] 5.00% [6],[7] 5.00% [6],[7] 5.00% [8],[11] 5.00% [8],[11] 5.00% [8],[11] 5.00% [8],[11] 5.00% [8],[11] 5.00% [8],[11] 5.00% [8],[11]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Principal amount $ 18,300,000 [7],[13]             $ 21,500,000 [11],[14]              
Amortized Cost 18,200,000 [7]             21,400,000 [11]              
Fair Value $ (17,800,000) [4],[7]             $ (21,200,000) [1],[11]              
Investment, Identifier [Axis]: Galaxy Universal LLC, Trade Claim, Consumer Durables & Apparel                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 7,701,195 [7],[32] 7,701,195 [7],[32] 7,701,195 [7],[32] 7,701,195 [7],[32] 7,701,195 [7],[32] 7,701,195 [7],[32] 7,701,195 [7],[32] 7,701,195 [11],[27] 7,701,195 [11],[27] 7,701,195 [11],[27] 7,701,195 [11],[27] 7,701,195 [11],[27] 7,701,195 [11],[27] 7,701,195 [11],[27]  
Amortized Cost $ 4,600,000 [7],[32]             $ 4,600,000 [11],[27]              
Fair Value $ (1,800,000) [4],[7],[32]             $ (1,700,000) [1],[11],[27]              
Investment, Identifier [Axis]: Galway Partners Holdings LLC, Insurance | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%  
Rate, PIK 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Rate, Max PIK 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 36,800,000             $ 36,900,000              
Amortized Cost 36,100,000             36,200,000              
Fair Value $ (36,100,000)             $ (36,400,000)              
Investment, Identifier [Axis]: Galway Partners Holdings LLC, Insurance 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [8],[9],[10],[11],[23],[42] 5.25% [8],[9],[10],[11],[23],[42] 5.25% [8],[9],[10],[11],[23],[42] 5.25% [8],[9],[10],[11],[23],[42] 5.25% [8],[9],[10],[11],[23],[42] 5.25% [8],[9],[10],[11],[23],[42] 5.25% [8],[9],[10],[11],[23],[42]  
Rate, PIK 0.00% [6],[7] 0.00% [6],[7] 0.00% [6],[7] 0.00% [6],[7] 0.00% [6],[7] 0.00% [6],[7] 0.00% [6],[7] 0.00% [8],[9],[10],[11],[23],[42] 0.00% [8],[9],[10],[11],[23],[42] 0.00% [8],[9],[10],[11],[23],[42] 0.00% [8],[9],[10],[11],[23],[42] 0.00% [8],[9],[10],[11],[23],[42] 0.00% [8],[9],[10],[11],[23],[42] 0.00% [8],[9],[10],[11],[23],[42]  
Rate, Max PIK 1.30% [6],[7] 1.30% [6],[7] 1.30% [6],[7] 1.30% [6],[7] 1.30% [6],[7] 1.30% [6],[7] 1.30% [6],[7] 1.30% [8],[9],[10],[11],[23],[42] 1.30% [8],[9],[10],[11],[23],[42] 1.30% [8],[9],[10],[11],[23],[42] 1.30% [8],[9],[10],[11],[23],[42] 1.30% [8],[9],[10],[11],[23],[42] 1.30% [8],[9],[10],[11],[23],[42] 1.30% [8],[9],[10],[11],[23],[42]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [9],[10],[11],[23],[42] 0.80% [9],[10],[11],[23],[42] 0.80% [9],[10],[11],[23],[42] 0.80% [9],[10],[11],[23],[42] 0.80% [9],[10],[11],[23],[42] 0.80% [9],[10],[11],[23],[42] 0.80% [9],[10],[11],[23],[42]  
Principal amount $ 2,600,000 [7],[13]             $ 111,100,000 [9],[10],[11],[14],[23],[42]              
Amortized Cost 2,400,000 [7]             109,400,000 [9],[10],[11],[23],[42]              
Fair Value $ (2,500,000) [4],[7]             $ (109,700,000) [1],[9],[10],[11],[23],[42]              
Investment, Identifier [Axis]: Galway Partners Holdings LLC, Insurance 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% [6],[7],[16],[17],[21],[41] 5.25% [6],[7],[16],[17],[21],[41] 5.25% [6],[7],[16],[17],[21],[41] 5.25% [6],[7],[16],[17],[21],[41] 5.25% [6],[7],[16],[17],[21],[41] 5.25% [6],[7],[16],[17],[21],[41] 5.25% [6],[7],[16],[17],[21],[41] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18]  
Rate, PIK 0.00% [6],[7],[16],[17],[21],[41] 0.00% [6],[7],[16],[17],[21],[41] 0.00% [6],[7],[16],[17],[21],[41] 0.00% [6],[7],[16],[17],[21],[41] 0.00% [6],[7],[16],[17],[21],[41] 0.00% [6],[7],[16],[17],[21],[41] 0.00% [6],[7],[16],[17],[21],[41] 0.00% [8],[18] 0.00% [8],[18] 0.00% [8],[18] 0.00% [8],[18] 0.00% [8],[18] 0.00% [8],[18] 0.00% [8],[18]  
Rate, Max PIK 1.30% [6],[7],[16],[17],[21],[41] 1.30% [6],[7],[16],[17],[21],[41] 1.30% [6],[7],[16],[17],[21],[41] 1.30% [6],[7],[16],[17],[21],[41] 1.30% [6],[7],[16],[17],[21],[41] 1.30% [6],[7],[16],[17],[21],[41] 1.30% [6],[7],[16],[17],[21],[41] 1.30% [8],[18] 1.30% [8],[18] 1.30% [8],[18] 1.30% [8],[18] 1.30% [8],[18] 1.30% [8],[18] 1.30% [8],[18]  
Base Rate Floor 0.80% [6],[7],[16],[17],[21],[41] 0.80% [6],[7],[16],[17],[21],[41] 0.80% [6],[7],[16],[17],[21],[41] 0.80% [6],[7],[16],[17],[21],[41] 0.80% [6],[7],[16],[17],[21],[41] 0.80% [6],[7],[16],[17],[21],[41] 0.80% [6],[7],[16],[17],[21],[41] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 110,800,000 [7],[13],[16],[17],[21],[41]             $ 12,000,000.0 [14],[18]              
Amortized Cost 109,200,000 [7],[16],[17],[21],[41]             11,800,000 [18]              
Fair Value $ (108,900,000) [4],[7],[16],[17],[21],[41]             $ (11,800,000) [1],[18]              
Investment, Identifier [Axis]: Galway Partners Holdings LLC, Insurance 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% [6],[19] 5.25% [6],[19] 5.25% [6],[19] 5.25% [6],[19] 5.25% [6],[19] 5.25% [6],[19] 5.25% [6],[19] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18]  
Rate, PIK 0.00% [6],[19] 0.00% [6],[19] 0.00% [6],[19] 0.00% [6],[19] 0.00% [6],[19] 0.00% [6],[19] 0.00% [6],[19] 0.00% [8],[18] 0.00% [8],[18] 0.00% [8],[18] 0.00% [8],[18] 0.00% [8],[18] 0.00% [8],[18] 0.00% [8],[18]  
Rate, Max PIK 1.30% [6],[19] 1.30% [6],[19] 1.30% [6],[19] 1.30% [6],[19] 1.30% [6],[19] 1.30% [6],[19] 1.30% [6],[19] 1.30% [8],[18] 1.30% [8],[18] 1.30% [8],[18] 1.30% [8],[18] 1.30% [8],[18] 1.30% [8],[18] 1.30% [8],[18]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 9,400,000 [13],[19]             $ 1,300,000 [14],[18]              
Amortized Cost 9,400,000 [19]             1,300,000 [18]              
Fair Value $ (9,200,000) [4],[19]             $ (1,300,000) [1],[18]              
Investment, Identifier [Axis]: Galway Partners Holdings LLC, Insurance 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19] 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%                
Rate, PIK [6],[19] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Rate, Max PIK [6],[19] 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30%                
Base Rate Floor [6],[19] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[19] $ 1,300,000                            
Amortized Cost [19] 1,300,000                            
Fair Value [4],[19] $ (1,300,000)                            
Investment, Identifier [Axis]: General Datatech LP, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[7],[16],[17],[20],[21],[41] 6.25% [6],[7],[16],[17],[20],[21],[41] 6.25% [6],[7],[16],[17],[20],[21],[41] 6.25% [6],[7],[16],[17],[20],[21],[41] 6.25% [6],[7],[16],[17],[20],[21],[41] 6.25% [6],[7],[16],[17],[20],[21],[41] 6.25% [6],[7],[16],[17],[20],[21],[41] 6.25% [8],[9],[10],[11],[22],[23],[42] 6.25% [8],[9],[10],[11],[22],[23],[42] 6.25% [8],[9],[10],[11],[22],[23],[42] 6.25% [8],[9],[10],[11],[22],[23],[42] 6.25% [8],[9],[10],[11],[22],[23],[42] 6.25% [8],[9],[10],[11],[22],[23],[42] 6.25% [8],[9],[10],[11],[22],[23],[42]  
Base Rate Floor 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42]  
Principal amount $ 155,400,000 [7],[13],[16],[17],[20],[21],[41]             $ 156,400,000 [9],[10],[11],[14],[22],[23],[42]              
Amortized Cost 154,200,000 [7],[16],[17],[20],[21],[41]             155,100,000 [9],[10],[11],[22],[23],[42]              
Fair Value $ (148,900,000) [4],[7],[16],[17],[20],[21],[41]             $ (146,500,000) [1],[9],[10],[11],[22],[23],[42]              
Investment, Identifier [Axis]: General Datatech LP, Software & Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 18,200,000             $ 18,300,000              
Amortized Cost 17,600,000             17,700,000              
Fair Value $ (17,400,000)             $ (17,100,000)              
Investment, Identifier [Axis]: Genesys Telecommunications Laboratories Inc, Class A Shares, Technology Hardware & Equipment                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [11],[27]               40,529 40,529 40,529 40,529 40,529 40,529 40,529  
Amortized Cost [11],[27]               $ 0              
Fair Value [1],[11],[27]               $ 0              
Investment, Identifier [Axis]: Genesys Telecommunications Laboratories Inc, Ordinary Shares, Technology Hardware & Equipment                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[32]               41,339 41,339 41,339 41,339 41,339 41,339 41,339  
Amortized Cost [7],[32]               $ 0              
Fair Value [1],[7],[32]               $ 0              
Investment, Identifier [Axis]: Genesys Telecommunications Laboratories Inc, Preferred Stock, Technology Hardware & Equipment                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[32]               1,050,465 1,050,465 1,050,465 1,050,465 1,050,465 1,050,465 1,050,465  
Amortized Cost [7],[32]               $ 0              
Fair Value [1],[7],[32]               $ 0              
Investment, Identifier [Axis]: Gigamon Inc, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 168,400,000 [7],[13]             $ 170,400,000 [11],[14]              
Amortized Cost 167,000,000.0 [7]             168,900,000 [11]              
Fair Value $ (164,700,000) [4],[7]             $ (163,200,000) [1],[11]              
Investment, Identifier [Axis]: Gigamon Inc, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 9,300,000 [13],[19]             $ 9,300,000 [14],[18]              
Amortized Cost 9,300,000 [19]             9,300,000 [18]              
Fair Value $ (9,100,000) [4],[19]             $ (8,900,000) [1],[18]              
Investment, Identifier [Axis]: Global Jet Capital LLC, Preferred Stock, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 149,494,590 [7],[13],[32],[53],[55] 149,494,590 [7],[13],[32],[53],[55] 149,494,590 [7],[13],[32],[53],[55] 149,494,590 [7],[13],[32],[53],[55] 149,494,590 [7],[13],[32],[53],[55] 149,494,590 [7],[13],[32],[53],[55] 149,494,590 [7],[13],[32],[53],[55] 149,494,590 [11],[14],[27],[54],[56] 149,494,590 [11],[14],[27],[54],[56] 149,494,590 [11],[14],[27],[54],[56] 149,494,590 [11],[14],[27],[54],[56] 149,494,590 [11],[14],[27],[54],[56] 149,494,590 [11],[14],[27],[54],[56] 149,494,590 [11],[14],[27],[54],[56]  
Amortized Cost $ 69,400,000 [7],[32],[53],[55]             $ 69,400,000 [11],[27],[54],[56]              
Fair Value $ 0 [4],[7],[32],[53],[55]             $ 0 [1],[11],[27],[54],[56]              
Investment, Identifier [Axis]: Global Jet Capital LLC, Preferred Stock, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 9.00% [6],[7],[29],[32],[53],[55] 9.00% [6],[7],[29],[32],[53],[55] 9.00% [6],[7],[29],[32],[53],[55] 9.00% [6],[7],[29],[32],[53],[55] 9.00% [6],[7],[29],[32],[53],[55] 9.00% [6],[7],[29],[32],[53],[55] 9.00% [6],[7],[29],[32],[53],[55] 9.00% [8],[11],[24],[27],[54],[56] 9.00% [8],[11],[24],[27],[54],[56] 9.00% [8],[11],[24],[27],[54],[56] 9.00% [8],[11],[24],[27],[54],[56] 9.00% [8],[11],[24],[27],[54],[56] 9.00% [8],[11],[24],[27],[54],[56] 9.00% [8],[11],[24],[27],[54],[56]  
Rate, Max PIK 9.00% [6],[7],[29],[32],[53],[55] 9.00% [6],[7],[29],[32],[53],[55] 9.00% [6],[7],[29],[32],[53],[55] 9.00% [6],[7],[29],[32],[53],[55] 9.00% [6],[7],[29],[32],[53],[55] 9.00% [6],[7],[29],[32],[53],[55] 9.00% [6],[7],[29],[32],[53],[55] 9.00% [8],[11],[24],[27],[54],[56] 9.00% [8],[11],[24],[27],[54],[56] 9.00% [8],[11],[24],[27],[54],[56] 9.00% [8],[11],[24],[27],[54],[56] 9.00% [8],[11],[24],[27],[54],[56] 9.00% [8],[11],[24],[27],[54],[56] 9.00% [8],[11],[24],[27],[54],[56]  
Principal amount $ 462,500,000 [7],[13],[29],[32],[53],[55]             $ 453,100,000 [11],[14],[24],[27],[54],[56]              
Amortized Cost 309,400,000 [7],[29],[32],[53],[55]             309,400,000 [11],[24],[27],[54],[56]              
Fair Value $ (238,800,000) [4],[7],[29],[32],[53],[55]             $ (232,200,000) [1],[11],[24],[27],[54],[56]              
Investment, Identifier [Axis]: Global Jet Capital LLC, Structured Mezzanine, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56]  
Rate, Max PIK 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56]  
Principal amount $ 16,700,000 [7],[13],[33],[53],[55]             $ 28,000,000.0 [11],[14],[28],[54],[56]              
Amortized Cost 13,600,000 [7],[33],[53],[55]             21,200,000 [11],[28],[54],[56]              
Fair Value $ (16,700,000) [4],[7],[33],[53],[55]             $ (28,000,000.0) [1],[11],[28],[54],[56]              
Investment, Identifier [Axis]: Global Jet Capital LLC, Structured Mezzanine, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56]  
Rate, Max PIK 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56]  
Principal amount $ 12,200,000 [7],[13],[33],[53],[55]             $ 20,500,000 [11],[14],[28],[54],[56]              
Amortized Cost 9,800,000 [7],[33],[53],[55]             15,100,000 [11],[28],[54],[56]              
Fair Value $ (12,200,000) [4],[7],[33],[53],[55]             $ (20,500,000) [1],[11],[28],[54],[56]              
Investment, Identifier [Axis]: Global Jet Capital LLC, Structured Mezzanine, Commercial & Professional Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56]  
Rate, Max PIK 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [6],[7],[33],[53],[55] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56] 15.00% [8],[11],[28],[54],[56]  
Principal amount $ 1,400,000 [7],[13],[33],[53],[55]             $ 2,400,000 [11],[14],[28],[54],[56]              
Amortized Cost 1,100,000 [7],[33],[53],[55]             1,700,000 [11],[28],[54],[56]              
Fair Value $ (1,400,000) [4],[7],[33],[53],[55]             $ (2,400,000) [1],[11],[28],[54],[56]              
Investment, Identifier [Axis]: Global Lending Services LLC, Private Equity, Diversified Financials 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [11],[14],[28]               7,391,109 7,391,109 7,391,109 7,391,109 7,391,109 7,391,109 7,391,109  
Amortized Cost [11],[28]               $ 8,600,000              
Fair Value [1],[11],[28]               $ (8,200,000)              
Investment, Identifier [Axis]: Global Lending Services LLC, Private Equity, Diversified Financials 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares               2,209,115 2,209,115 2,209,115 2,209,115 2,209,115 2,209,115 2,209,115  
Amortized Cost               $ 2,200,000              
Fair Value               $ (2,400,000)              
Investment, Identifier [Axis]: Global Lending Services LLC, Private Equity, Diversified Financials 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [11],[14],[28]               10,356,657 10,356,657 10,356,657 10,356,657 10,356,657 10,356,657 10,356,657  
Amortized Cost [11],[28]               $ 10,400,000              
Fair Value [1],[11],[28]               $ (10,900,000)              
Investment, Identifier [Axis]: Global Lending Services LLC, Private Equity, Diversified Financials 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares               17,450,851 17,450,851 17,450,851 17,450,851 17,450,851 17,450,851 17,450,851  
Amortized Cost               $ 22,900,000              
Fair Value               $ (18,300,000)              
Investment, Identifier [Axis]: Global Lending Services LLC, Private Equity, Diversified Financials 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [11],[14],[27],[28]               9,963,808 9,963,808 9,963,808 9,963,808 9,963,808 9,963,808 9,963,808  
Amortized Cost [11],[27],[28]               $ 10,000,000.0              
Fair Value [1],[11],[27],[28]               $ (10,000,000.0)              
Investment, Identifier [Axis]: Global Lending Services LLC, Private Equity, Financial Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[13],[33] 6,305,388 6,305,388 6,305,388 6,305,388 6,305,388 6,305,388 6,305,388                
Amortized Cost [7],[33] $ 7,300,000                            
Fair Value [4],[7],[33] $ (7,200,000)                            
Investment, Identifier [Axis]: Global Lending Services LLC, Private Equity, Financial Services 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 1,884,606 1,884,606 1,884,606 1,884,606 1,884,606 1,884,606 1,884,606                
Amortized Cost $ 1,900,000                            
Fair Value $ (2,200,000)                            
Investment, Identifier [Axis]: Global Lending Services LLC, Private Equity, Financial Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[13],[33] 9,625,411 9,625,411 9,625,411 9,625,411 9,625,411 9,625,411 9,625,411                
Amortized Cost [7],[33] $ 9,600,000                            
Fair Value [4],[7],[33] $ (9,800,000)                            
Investment, Identifier [Axis]: Global Lending Services LLC, Private Equity, Financial Services 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 16,218,551 16,218,551 16,218,551 16,218,551 16,218,551 16,218,551 16,218,551                
Amortized Cost $ 21,300,000                            
Fair Value $ (16,500,000)                            
Investment, Identifier [Axis]: Global Lending Services LLC, Private Equity, Financial Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[13],[32],[33] 13,864,865 13,864,865 13,864,865 13,864,865 13,864,865 13,864,865 13,864,865                
Amortized Cost [7],[32],[33] $ 13,900,000                            
Fair Value [4],[7],[32],[33] $ (14,100,000)                            
Investment, Identifier [Axis]: Gracent LLC, Health Care Equipment & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Principal amount $ 25,800,000 [7],[13]             $ 25,900,000 [11],[14]              
Amortized Cost 26,500,000 [7]             26,600,000 [11]              
Fair Value $ (22,100,000) [4],[7]             $ (22,100,000) [1],[11]              
Investment, Identifier [Axis]: Gracent LLC, Health Care Equipment & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 12.00% [6],[7],[29],[32] 12.00% [6],[7],[29],[32] 12.00% [6],[7],[29],[32] 12.00% [6],[7],[29],[32] 12.00% [6],[7],[29],[32] 12.00% [6],[7],[29],[32] 12.00% [6],[7],[29],[32] 12.00% [8],[11],[24],[27] 12.00% [8],[11],[24],[27] 12.00% [8],[11],[24],[27] 12.00% [8],[11],[24],[27] 12.00% [8],[11],[24],[27] 12.00% [8],[11],[24],[27] 12.00% [8],[11],[24],[27]  
Rate, Max PIK 12.00% [6],[7],[29],[32] 12.00% [6],[7],[29],[32] 12.00% [6],[7],[29],[32] 12.00% [6],[7],[29],[32] 12.00% [6],[7],[29],[32] 12.00% [6],[7],[29],[32] 12.00% [6],[7],[29],[32] 12.00% [8],[11],[24],[27] 12.00% [8],[11],[24],[27] 12.00% [8],[11],[24],[27] 12.00% [8],[11],[24],[27] 12.00% [8],[11],[24],[27] 12.00% [8],[11],[24],[27] 12.00% [8],[11],[24],[27]  
Principal amount $ 23,500,000 [7],[13],[29],[32]             $ 22,900,000 [11],[14],[24],[27]              
Amortized Cost 22,900,000 [7],[29],[32]             22,600,000 [11],[24],[27]              
Fair Value $ (9,100,000) [4],[7],[29],[32]             $ (11,400,000) [1],[11],[24],[27]              
Investment, Identifier [Axis]: Gracent LLC, NP-1 Common Stock, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 1,000,000 [32],[51] 1,000,000 [32],[51] 1,000,000 [32],[51] 1,000,000 [32],[51] 1,000,000 [32],[51] 1,000,000 [32],[51] 1,000,000 [32],[51] 1,000,000 [27],[48] 1,000,000 [27],[48] 1,000,000 [27],[48] 1,000,000 [27],[48] 1,000,000 [27],[48] 1,000,000 [27],[48] 1,000,000 [27],[48]  
Amortized Cost $ 4,200,000 [32],[51]             $ 4,200,000 [27],[48]              
Fair Value $ 0 [4],[32],[51]             $ 0 [1],[27],[48]              
Investment, Identifier [Axis]: Greystone Equity Member Corp, Diversified Financials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11],[28]               7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25%  
Base Rate Floor [11],[28]               3.80% 3.80% 3.80% 3.80% 3.80% 3.80% 3.80%  
Principal amount [11],[14],[28]               $ 194,800,000              
Amortized Cost [11],[28]               185,000,000.0              
Fair Value [1],[11],[28]               $ (188,700,000)              
Investment, Identifier [Axis]: Greystone Equity Member Corp, Diversified Financials | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate               7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25%  
Base Rate Floor               3.80% 3.80% 3.80% 3.80% 3.80% 3.80% 3.80%  
Principal amount               $ 30,200,000              
Amortized Cost               30,100,000              
Fair Value               $ (29,300,000)              
Investment, Identifier [Axis]: Greystone Equity Member Corp, Financial Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[33] 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25%                
Base Rate Floor [6],[7],[33] 3.80% 3.80% 3.80% 3.80% 3.80% 3.80% 3.80%                
Principal amount [7],[13],[33] $ 194,800,000                            
Amortized Cost [7],[33] 185,600,000                            
Fair Value [4],[7],[33] $ (187,200,000)                            
Investment, Identifier [Axis]: Greystone Equity Member Corp, Financial Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25%                
Base Rate Floor 3.80% 3.80% 3.80% 3.80% 3.80% 3.80% 3.80%                
Principal amount $ 30,200,000                            
Amortized Cost 30,100,000                            
Fair Value $ (29,100,000)                            
Investment, Identifier [Axis]: HKA, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[7],[33],[41] 5.75% [6],[7],[33],[41] 5.75% [6],[7],[33],[41] 5.75% [6],[7],[33],[41] 5.75% [6],[7],[33],[41] 5.75% [6],[7],[33],[41] 5.75% [6],[7],[33],[41] 5.75% [8],[11],[28] 5.75% [8],[11],[28] 5.75% [8],[11],[28] 5.75% [8],[11],[28] 5.75% [8],[11],[28] 5.75% [8],[11],[28] 5.75% [8],[11],[28]  
Rate, PIK 0.00% [6],[7],[33],[41] 0.00% [6],[7],[33],[41] 0.00% [6],[7],[33],[41] 0.00% [6],[7],[33],[41] 0.00% [6],[7],[33],[41] 0.00% [6],[7],[33],[41] 0.00% [6],[7],[33],[41] 0.00% [8],[11],[28] 0.00% [8],[11],[28] 0.00% [8],[11],[28] 0.00% [8],[11],[28] 0.00% [8],[11],[28] 0.00% [8],[11],[28] 0.00% [8],[11],[28]  
Rate, Max PIK 1.80% [6],[7],[33],[41] 1.80% [6],[7],[33],[41] 1.80% [6],[7],[33],[41] 1.80% [6],[7],[33],[41] 1.80% [6],[7],[33],[41] 1.80% [6],[7],[33],[41] 1.80% [6],[7],[33],[41] 1.80% [8],[11],[28] 1.80% [8],[11],[28] 1.80% [8],[11],[28] 1.80% [8],[11],[28] 1.80% [8],[11],[28] 1.80% [8],[11],[28] 1.80% [8],[11],[28]  
Base Rate Floor 0.50% [6],[7],[33],[41] 0.50% [6],[7],[33],[41] 0.50% [6],[7],[33],[41] 0.50% [6],[7],[33],[41] 0.50% [6],[7],[33],[41] 0.50% [6],[7],[33],[41] 0.50% [6],[7],[33],[41] 0.50% [11],[28] 0.50% [11],[28] 0.50% [11],[28] 0.50% [11],[28] 0.50% [11],[28] 0.50% [11],[28] 0.50% [11],[28]  
Principal amount $ 4,400,000 [7],[13],[33],[41]             $ 4,400,000 [11],[14],[28]              
Amortized Cost 4,300,000 [7],[33],[41]             4,300,000 [11],[28]              
Fair Value $ (4,300,000) [4],[7],[33],[41]             $ (4,200,000) [1],[11],[28]              
Investment, Identifier [Axis]: HKA, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[19],[33] 5.75% [6],[19],[33] 5.75% [6],[19],[33] 5.75% [6],[19],[33] 5.75% [6],[19],[33] 5.75% [6],[19],[33] 5.75% [6],[19],[33] 5.75% [8],[18],[28] 5.75% [8],[18],[28] 5.75% [8],[18],[28] 5.75% [8],[18],[28] 5.75% [8],[18],[28] 5.75% [8],[18],[28] 5.75% [8],[18],[28]  
Rate, PIK 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [8],[18],[28] 0.00% [8],[18],[28] 0.00% [8],[18],[28] 0.00% [8],[18],[28] 0.00% [8],[18],[28] 0.00% [8],[18],[28] 0.00% [8],[18],[28]  
Rate, Max PIK 1.80% [6],[19],[33] 1.80% [6],[19],[33] 1.80% [6],[19],[33] 1.80% [6],[19],[33] 1.80% [6],[19],[33] 1.80% [6],[19],[33] 1.80% [6],[19],[33] 1.80% 1.80% 1.80% 1.80% 1.80% 1.80% 1.80%  
Base Rate Floor 0.50% [6],[19],[33] 0.50% [6],[19],[33] 0.50% [6],[19],[33] 0.50% [6],[19],[33] 0.50% [6],[19],[33] 0.50% [6],[19],[33] 0.50% [6],[19],[33] 0.50% [18],[28] 0.50% [18],[28] 0.50% [18],[28] 0.50% [18],[28] 0.50% [18],[28] 0.50% [18],[28] 0.50% [18],[28]  
Principal amount $ 200,000 [13],[19],[33]             $ 200,000 [14],[18],[28]              
Amortized Cost 200,000 [19],[33]             200,000 [18],[28]              
Fair Value (200,000) [4],[19],[33]             (200,000) [1],[18],[28]              
Investment, Identifier [Axis]: HM Dunn Co Inc 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value (35,300,000)             (35,600,000)             (33,600,000)
Investment, Identifier [Axis]: HM Dunn Co Inc 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ 0             $ 0             (2,000,000.0)
Investment, Identifier [Axis]: HM Dunn Co Inc, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[7],[34] 6.00% [6],[7],[34] 6.00% [6],[7],[34] 6.00% [6],[7],[34] 6.00% [6],[7],[34] 6.00% [6],[7],[34] 6.00% [6],[7],[34] 6.00% [8],[11],[35] 6.00% [8],[11],[35] 6.00% [8],[11],[35] 6.00% [8],[11],[35] 6.00% [8],[11],[35] 6.00% [8],[11],[35] 6.00% [8],[11],[35]  
Rate, PIK 0.00% [6],[7],[34] 0.00% [6],[7],[34] 0.00% [6],[7],[34] 0.00% [6],[7],[34] 0.00% [6],[7],[34] 0.00% [6],[7],[34] 0.00% [6],[7],[34] 0.00% [8],[11],[35] 0.00% [8],[11],[35] 0.00% [8],[11],[35] 0.00% [8],[11],[35] 0.00% [8],[11],[35] 0.00% [8],[11],[35] 0.00% [8],[11],[35]  
Rate, Max PIK 6.00% [6],[7],[34] 6.00% [6],[7],[34] 6.00% [6],[7],[34] 6.00% [6],[7],[34] 6.00% [6],[7],[34] 6.00% [6],[7],[34] 6.00% [6],[7],[34] 6.00% [8],[11],[35] 6.00% [8],[11],[35] 6.00% [8],[11],[35] 6.00% [8],[11],[35] 6.00% [8],[11],[35] 6.00% [8],[11],[35] 6.00% [8],[11],[35]  
Base Rate Floor 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35]  
Principal amount $ 35,300,000 [7],[13],[34]             $ 35,600,000 [11],[14],[35]              
Amortized Cost 35,300,000 [7],[34]             35,600,000 [11],[35]              
Fair Value $ (35,300,000) [4],[7],[34]             $ (35,600,000) [1],[11],[35]              
Investment, Identifier [Axis]: HM Dunn Co Inc, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[19],[34] 6.00% [6],[19],[34] 6.00% [6],[19],[34] 6.00% [6],[19],[34] 6.00% [6],[19],[34] 6.00% [6],[19],[34] 6.00% [6],[19],[34] 6.00% [8],[18],[35] 6.00% [8],[18],[35] 6.00% [8],[18],[35] 6.00% [8],[18],[35] 6.00% [8],[18],[35] 6.00% [8],[18],[35] 6.00% [8],[18],[35]  
Rate, PIK 0.00% [6],[19],[34] 0.00% [6],[19],[34] 0.00% [6],[19],[34] 0.00% [6],[19],[34] 0.00% [6],[19],[34] 0.00% [6],[19],[34] 0.00% [6],[19],[34] 0.00% [8],[18],[35] 0.00% [8],[18],[35] 0.00% [8],[18],[35] 0.00% [8],[18],[35] 0.00% [8],[18],[35] 0.00% [8],[18],[35] 0.00% [8],[18],[35]  
Rate, Max PIK 6.00% [6],[19],[34] 6.00% [6],[19],[34] 6.00% [6],[19],[34] 6.00% [6],[19],[34] 6.00% [6],[19],[34] 6.00% [6],[19],[34] 6.00% [6],[19],[34] 6.00% [8],[18],[35] 6.00% [8],[18],[35] 6.00% [8],[18],[35] 6.00% [8],[18],[35] 6.00% [8],[18],[35] 6.00% [8],[18],[35] 6.00% [8],[18],[35]  
Base Rate Floor 1.00% [6],[19],[34] 1.00% [6],[19],[34] 1.00% [6],[19],[34] 1.00% [6],[19],[34] 1.00% [6],[19],[34] 1.00% [6],[19],[34] 1.00% [6],[19],[34] 1.00% [18],[35] 1.00% [18],[35] 1.00% [18],[35] 1.00% [18],[35] 1.00% [18],[35] 1.00% [18],[35] 1.00% [18],[35]  
Principal amount $ 2,000,000.0 [13],[19],[34]             $ 2,000,000.0 [14],[18],[35]              
Amortized Cost 2,000,000.0 [19],[34]             2,000,000.0 [18],[35]              
Fair Value (2,000,000.0) [4],[19],[34]             (2,000,000.0) [1],[18],[35]              
Investment, Identifier [Axis]: HM Dunn Co Inc, Preferred Stock, Series A                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (16,600,000)             $ (16,900,000)             (7,100,000)
Investment, Identifier [Axis]: HM Dunn Co Inc, Preferred Stock, Series A, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 85,385 [7],[32],[34],[36] 85,385 [7],[32],[34],[36] 85,385 [7],[32],[34],[36] 85,385 [7],[32],[34],[36] 85,385 [7],[32],[34],[36] 85,385 [7],[32],[34],[36] 85,385 [7],[32],[34],[36] 85,385 [11],[27],[35],[37] 85,385 [11],[27],[35],[37] 85,385 [11],[27],[35],[37] 85,385 [11],[27],[35],[37] 85,385 [11],[27],[35],[37] 85,385 [11],[27],[35],[37] 85,385 [11],[27],[35],[37]  
Amortized Cost $ 7,100,000 [7],[32],[34],[36]             $ 7,100,000 [11],[27],[35],[37]              
Fair Value (16,600,000) [4],[7],[32],[34],[36]             (16,900,000) [1],[11],[27],[35],[37]              
Investment, Identifier [Axis]: HM Dunn Co Inc, Preferred Stock, Series B                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ 0             $ 0             0
Investment, Identifier [Axis]: HM Dunn Co Inc, Preferred Stock, Series B, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 15,000 [7],[32],[34],[36] 15,000 [7],[32],[34],[36] 15,000 [7],[32],[34],[36] 15,000 [7],[32],[34],[36] 15,000 [7],[32],[34],[36] 15,000 [7],[32],[34],[36] 15,000 [7],[32],[34],[36] 15,000 [11],[27],[35],[37] 15,000 [11],[27],[35],[37] 15,000 [11],[27],[35],[37] 15,000 [11],[27],[35],[37] 15,000 [11],[27],[35],[37] 15,000 [11],[27],[35],[37] 15,000 [11],[27],[35],[37]  
Amortized Cost $ 0 [7],[32],[34],[36]             $ 0 [11],[27],[35],[37]              
Fair Value $ 0 [4],[7],[32],[34],[36]             $ 0 [1],[11],[27],[35],[37]              
Investment, Identifier [Axis]: Harvey Industries Inc, Common Stock, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[32] 5,000,000 5,000,000 5,000,000 5,000,000 5,000,000 5,000,000 5,000,000 5,000,000 5,000,000 5,000,000 5,000,000 5,000,000 5,000,000 5,000,000  
Amortized Cost [7],[32] $ 2,200,000             $ 2,200,000              
Fair Value [7],[32] $ (6,200,000) [4]             $ (5,200,000) [1]              
Investment, Identifier [Axis]: HealthChannels LLC, Health Care Equipment & Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 4.50%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount $ 15,400,000             $ 15,400,000              
Amortized Cost 15,300,000             15,300,000              
Fair Value $ (9,100,000)             $ (10,900,000)              
Investment, Identifier [Axis]: Heniff Transportation Systems LLC, Transportation 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [8],[9],[10],[11],[12],[22],[42] 5.75% [8],[9],[10],[11],[12],[22],[42] 5.75% [8],[9],[10],[11],[12],[22],[42] 5.75% [8],[9],[10],[11],[12],[22],[42] 5.75% [8],[9],[10],[11],[12],[22],[42] 5.75% [8],[9],[10],[11],[12],[22],[42] 5.75% [8],[9],[10],[11],[12],[22],[42]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [9],[10],[11],[12],[22],[42] 1.00% [9],[10],[11],[12],[22],[42] 1.00% [9],[10],[11],[12],[22],[42] 1.00% [9],[10],[11],[12],[22],[42] 1.00% [9],[10],[11],[12],[22],[42] 1.00% [9],[10],[11],[12],[22],[42] 1.00% [9],[10],[11],[12],[22],[42]  
Principal amount $ 3,500,000 [7],[13]             $ 135,700,000 [9],[10],[11],[12],[14],[22],[42]              
Amortized Cost 3,300,000 [7]             129,800,000 [9],[10],[11],[12],[22],[42]              
Fair Value $ (3,400,000) [4],[7]             $ (131,300,000) [1],[9],[10],[11],[12],[22],[42]              
Investment, Identifier [Axis]: Heniff Transportation Systems LLC, Transportation 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[7],[15],[16],[17],[20],[41] 5.75% [6],[7],[15],[16],[17],[20],[41] 5.75% [6],[7],[15],[16],[17],[20],[41] 5.75% [6],[7],[15],[16],[17],[20],[41] 5.75% [6],[7],[15],[16],[17],[20],[41] 5.75% [6],[7],[15],[16],[17],[20],[41] 5.75% [6],[7],[15],[16],[17],[20],[41] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11]  
Base Rate Floor 1.00% [6],[7],[15],[16],[17],[20],[41] 1.00% [6],[7],[15],[16],[17],[20],[41] 1.00% [6],[7],[15],[16],[17],[20],[41] 1.00% [6],[7],[15],[16],[17],[20],[41] 1.00% [6],[7],[15],[16],[17],[20],[41] 1.00% [6],[7],[15],[16],[17],[20],[41] 1.00% [6],[7],[15],[16],[17],[20],[41] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Principal amount $ 134,900,000 [7],[13],[15],[16],[17],[20],[41]             $ 19,100,000 [11],[14]              
Amortized Cost 129,200,000 [7],[15],[16],[17],[20],[41]             18,400,000 [11]              
Fair Value $ (132,700,000) [4],[7],[15],[16],[17],[20],[41]             $ (18,500,000) [1],[11]              
Investment, Identifier [Axis]: Heniff Transportation Systems LLC, Transportation 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 19,000,000.0 [7],[13]             $ 17,800,000 [14],[18]              
Amortized Cost 18,300,000 [7]             17,600,000 [18]              
Fair Value $ (18,700,000) [4],[7]             $ (17,200,000) [1],[18]              
Investment, Identifier [Axis]: Heniff Transportation Systems LLC, Transportation 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base Rate Floor [6],[19] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[19] $ 14,300,000                            
Amortized Cost [19] 14,300,000                            
Fair Value [4],[19] $ (14,100,000)                            
Investment, Identifier [Axis]: Hermes UK Ltd, Transportation | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | £         £ 14.7             £ 14.7      
Amortized Cost $ 19,600,000             $ 19,500,000              
Fair Value $ (16,700,000)             $ (16,100,000)              
Investment, Identifier [Axis]: Hibu Inc, Commercial & Professional Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[7],[16],[17],[20],[21],[41] 6.25% [6],[7],[16],[17],[20],[21],[41] 6.25% [6],[7],[16],[17],[20],[21],[41] 6.25% [6],[7],[16],[17],[20],[21],[41] 6.25% [6],[7],[16],[17],[20],[21],[41] 6.25% [6],[7],[16],[17],[20],[21],[41] 6.25% [6],[7],[16],[17],[20],[21],[41] 6.25% [8],[9],[10],[11],[22],[23],[42] 6.25% [8],[9],[10],[11],[22],[23],[42] 6.25% [8],[9],[10],[11],[22],[23],[42] 6.25% [8],[9],[10],[11],[22],[23],[42] 6.25% [8],[9],[10],[11],[22],[23],[42] 6.25% [8],[9],[10],[11],[22],[23],[42] 6.25% [8],[9],[10],[11],[22],[23],[42]  
Base Rate Floor 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42]  
Principal amount $ 98,300,000 [7],[13],[16],[17],[20],[21],[41]             $ 99,000,000.0 [9],[10],[11],[14],[22],[23],[42]              
Amortized Cost 94,400,000 [7],[16],[17],[20],[21],[41]             94,800,000 [9],[10],[11],[22],[23],[42]              
Fair Value $ (99,300,000) [4],[7],[16],[17],[20],[21],[41]             $ (99,800,000) [1],[9],[10],[11],[22],[23],[42]              
Investment, Identifier [Axis]: Higginbotham Insurance Agency Inc, Insurance | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 37,500,000             $ 37,600,000              
Amortized Cost 37,900,000             38,000,000.0              
Fair Value $ (37,300,000)             $ (37,700,000)              
Investment, Identifier [Axis]: Higginbotham Insurance Agency Inc, Insurance 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 6,600,000 [7],[13]             $ 4,400,000 [11],[14]              
Amortized Cost 6,600,000 [7]             4,400,000 [11]              
Fair Value $ (6,600,000) [4],[7]             $ (4,400,000) [1],[11]              
Investment, Identifier [Axis]: Higginbotham Insurance Agency Inc, Insurance 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [8],[11] 5.25% [8],[11] 5.25% [8],[11] 5.25% [8],[11] 5.25% [8],[11] 5.25% [8],[11] 5.25% [8],[11]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 7,000,000.0 [7],[13]             $ 7,000,000.0 [11],[14]              
Amortized Cost 6,600,000 [7]             6,600,000 [11]              
Fair Value $ (6,900,000) [4],[7]             $ (7,000,000.0) [1],[11]              
Investment, Identifier [Axis]: Higginbotham Insurance Agency Inc, Insurance 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 3,700,000 [13],[19]             $ 6,000,000.0 [14],[18]              
Amortized Cost 3,700,000 [19]             6,000,000.0 [18]              
Fair Value (3,700,000) [4],[19]             (6,000,000.0) [1],[18]              
Investment, Identifier [Axis]: Hilding Anders 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value 0             0             (46,600,000)
Investment, Identifier [Axis]: Hilding Anders 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value 0             0             0
Investment, Identifier [Axis]: Hilding Anders 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value 0             0             0
Investment, Identifier [Axis]: Hilding Anders, Class A Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ 0             $ 0             0
Investment, Identifier [Axis]: Hilding Anders, Class A Common Stock, Consumer Durables & Apparel                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 4,503,411 [7],[32],[33],[34] 4,503,411 [7],[32],[33],[34] 4,503,411 [7],[32],[33],[34] 4,503,411 [7],[32],[33],[34] 4,503,411 [7],[32],[33],[34] 4,503,411 [7],[32],[33],[34] 4,503,411 [7],[32],[33],[34] 4,503,411 [11],[27],[28],[35] 4,503,411 [11],[27],[28],[35] 4,503,411 [11],[27],[28],[35] 4,503,411 [11],[27],[28],[35] 4,503,411 [11],[27],[28],[35] 4,503,411 [11],[27],[28],[35] 4,503,411 [11],[27],[28],[35]  
Amortized Cost $ 100,000 [7],[32],[33],[34]             $ 100,000 [11],[27],[28],[35]              
Fair Value 0 [4],[7],[32],[33],[34]             0 [1],[11],[27],[28],[35]              
Investment, Identifier [Axis]: Hilding Anders, Class B Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ 0             $ 0             0
Investment, Identifier [Axis]: Hilding Anders, Class B Common Stock, Consumer Durables & Apparel                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 574,791 [7],[32],[33],[34] 574,791 [7],[32],[33],[34] 574,791 [7],[32],[33],[34] 574,791 [7],[32],[33],[34] 574,791 [7],[32],[33],[34] 574,791 [7],[32],[33],[34] 574,791 [7],[32],[33],[34] 574,791 [11],[27],[28],[35] 574,791 [11],[27],[28],[35] 574,791 [11],[27],[28],[35] 574,791 [11],[27],[28],[35] 574,791 [11],[27],[28],[35] 574,791 [11],[27],[28],[35] 574,791 [11],[27],[28],[35]  
Amortized Cost $ 0 [7],[32],[33],[34]             $ 0 [11],[27],[28],[35]              
Fair Value (0.0) [4],[7],[32],[33],[34]             0 [1],[11],[27],[28],[35]              
Investment, Identifier [Axis]: Hilding Anders, Class C Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ 0             $ 0             0
Investment, Identifier [Axis]: Hilding Anders, Class C Common Stock, Consumer Durables & Apparel                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 213,201 [7],[32],[33],[34] 213,201 [7],[32],[33],[34] 213,201 [7],[32],[33],[34] 213,201 [7],[32],[33],[34] 213,201 [7],[32],[33],[34] 213,201 [7],[32],[33],[34] 213,201 [7],[32],[33],[34] 213,201 [11],[27],[28],[35] 213,201 [11],[27],[28],[35] 213,201 [11],[27],[28],[35] 213,201 [11],[27],[28],[35] 213,201 [11],[27],[28],[35] 213,201 [11],[27],[28],[35] 213,201 [11],[27],[28],[35]  
Amortized Cost $ 0 [7],[32],[33],[34]             $ 0 [11],[27],[28],[35]              
Fair Value 0 [4],[7],[32],[33],[34]             $ 0 [1],[11],[27],[28],[35]              
Investment, Identifier [Axis]: Hilding Anders, Consumer Durables & Apparel 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount | €       € 135.2 [7],[32],[33],[34]             € 135.2 [11],[14],[27],[28],[35]        
Amortized Cost 26,900,000 [7],[32],[33],[34]                   26.9 [11],[27],[28],[35]        
Fair Value $ 0 [7],[32],[33],[34]                   € 0.0 [1],[11],[27],[28],[35]        
Investment, Identifier [Axis]: Hilding Anders, Consumer Durables & Apparel 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 13.00% [7],[29],[32],[33],[34] 13.00% [7],[29],[32],[33],[34] 13.00% [7],[29],[32],[33],[34] 13.00% [7],[29],[32],[33],[34] 13.00% [7],[29],[32],[33],[34] 13.00% [7],[29],[32],[33],[34] 13.00% [7],[29],[32],[33],[34] 13.00% [8],[11],[24],[27],[28],[35] 13.00% [8],[11],[24],[27],[28],[35] 13.00% [8],[11],[24],[27],[28],[35] 13.00% [8],[11],[24],[27],[28],[35] 13.00% [8],[11],[24],[27],[28],[35] 13.00% [8],[11],[24],[27],[28],[35] 13.00% [8],[11],[24],[27],[28],[35]  
Rate, Max PIK 13.00% [7],[29],[32],[33],[34] 13.00% [7],[29],[32],[33],[34] 13.00% [7],[29],[32],[33],[34] 13.00% [7],[29],[32],[33],[34] 13.00% [7],[29],[32],[33],[34] 13.00% [7],[29],[32],[33],[34] 13.00% [7],[29],[32],[33],[34] 13.00% [8],[11],[24],[27],[28],[35] 13.00% [8],[11],[24],[27],[28],[35] 13.00% [8],[11],[24],[27],[28],[35] 13.00% [8],[11],[24],[27],[28],[35] 13.00% [8],[11],[24],[27],[28],[35] 13.00% [8],[11],[24],[27],[28],[35] 13.00% [8],[11],[24],[27],[28],[35]  
Principal amount | €       € 152.6 [7],[29],[32],[33],[34]             € 152.6 [11],[14],[24],[27],[28],[35]        
Amortized Cost $ 99,400,000 [7],[29],[32],[33],[34]                   99.4 [11],[24],[27],[28],[35]        
Fair Value 0 [7],[29],[32],[33],[34]                   € 0.0 [1],[11],[24],[27],[28],[35]        
Investment, Identifier [Axis]: Hilding Anders, Equity Options                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ 0             $ 0             0
Investment, Identifier [Axis]: Hilding Anders, Equity Options, Consumer Durables & Apparel                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 236,160,807 [7],[32],[33],[34] 236,160,807 [7],[32],[33],[34] 236,160,807 [7],[32],[33],[34] 236,160,807 [7],[32],[33],[34] 236,160,807 [7],[32],[33],[34] 236,160,807 [7],[32],[33],[34] 236,160,807 [7],[32],[33],[34] 236,160,807 [11],[27],[28],[35] 236,160,807 [11],[27],[28],[35] 236,160,807 [11],[27],[28],[35] 236,160,807 [11],[27],[28],[35] 236,160,807 [11],[27],[28],[35] 236,160,807 [11],[27],[28],[35] 236,160,807 [11],[27],[28],[35]  
Amortized Cost $ 15,000,000.0 [7],[32],[33],[34]             $ 15,000,000.0 [11],[27],[28],[35]              
Fair Value 0 [4],[7],[32],[33],[34]             0 [1],[11],[27],[28],[35]              
Investment, Identifier [Axis]: Home Partners JV 2, Private Equity 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value (200,000)             (200,000)              
Investment, Identifier [Axis]: Home Partners JV 2, Private Equity 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (4,500,000)             $ (5,000,000.0)              
Investment, Identifier [Axis]: Home Partners JV 2, Private Equity, Equity Real Estate Investment Trusts (REITs) 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[13],[32],[33],[43] 4,471,509 4,471,509 4,471,509 4,471,509 4,471,509 4,471,509 4,471,509                
Amortized Cost [7],[32],[33],[43] $ 4,400,000                            
Fair Value [4],[7],[32],[33],[43] $ (4,500,000)                            
Investment, Identifier [Axis]: Home Partners JV 2, Private Equity, Equity Real Estate Investment Trusts (REITs) 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[13],[32],[33],[43] 168,710 168,710 168,710 168,710 168,710 168,710 168,710                
Amortized Cost [7],[32],[33],[43] $ 200,000                            
Fair Value [4],[7],[32],[33],[43] (200,000)                            
Investment, Identifier [Axis]: Home Partners JV 2, Private Equity, Real Estate 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [11],[14],[27],[28],[44]               4,471,509 4,471,509 4,471,509 4,471,509 4,471,509 4,471,509 4,471,509  
Amortized Cost [11],[27],[28],[44]               $ 4,400,000              
Fair Value [1],[11],[27],[28],[44]               $ (5,000,000.0)              
Investment, Identifier [Axis]: Home Partners JV 2, Private Equity, Real Estate 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [11],[14],[27],[28],[44]               168,710 168,710 168,710 168,710 168,710 168,710 168,710  
Amortized Cost [11],[27],[28],[44]               $ 200,000              
Fair Value [1],[11],[27],[28],[44]               (200,000)              
Investment, Identifier [Axis]: Home Partners JV 2, Structured Mezzanine                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (10,500,000)             (10,200,000)              
Investment, Identifier [Axis]: Home Partners JV 2, Structured Mezzanine, Asset Based Finance                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ (10,200,000)             (3,500,000)
Investment, Identifier [Axis]: Home Partners JV 2, Structured Mezzanine, Equity Real Estate Investment Trusts (REITs)                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK [6],[7],[33],[43] 11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%                
Rate, Max PIK [6],[7],[33],[43] 11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%                
Principal amount [7],[13],[33],[43] $ 10,500,000                            
Amortized Cost [7],[33],[43] 10,500,000                            
Fair Value [4],[7],[33],[43] $ (10,500,000)                            
Investment, Identifier [Axis]: Home Partners JV 2, Structured Mezzanine, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK [11],[28],[44]               11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%  
Rate, Max PIK [11],[28],[44]               11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%  
Principal amount [11],[14],[28],[44]               $ 10,200,000              
Amortized Cost [11],[28],[44]               10,200,000              
Fair Value [1],[11],[28],[44]               (10,200,000)              
Investment, Identifier [Axis]: Home Partners JV, Common Stock, Asset Based Finance -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ 0             (80,600,000)
Investment, Identifier [Axis]: Imagine Communications Corp, Common Stock, Media & Entertainment                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[32] 33,034 33,034 33,034 33,034 33,034 33,034 33,034 33,034 33,034 33,034 33,034 33,034 33,034 33,034  
Amortized Cost [7],[32] $ 3,800,000             $ 3,800,000              
Fair Value [7],[32] $ (2,000,000.0) [4]             $ (2,000,000.0) [1]              
Investment, Identifier [Axis]: Individual FoodService, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[7],[36] 6.25% [6],[7],[36] 6.25% [6],[7],[36] 6.25% [6],[7],[36] 6.25% [6],[7],[36] 6.25% [6],[7],[36] 6.25% [6],[7],[36] 6.25% [8],[37],[42] 6.25% [8],[37],[42] 6.25% [8],[37],[42] 6.25% [8],[37],[42] 6.25% [8],[37],[42] 6.25% [8],[37],[42] 6.25% [8],[37],[42]  
Base Rate Floor 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [37],[42] 1.00% [37],[42] 1.00% [37],[42] 1.00% [37],[42] 1.00% [37],[42] 1.00% [37],[42] 1.00% [37],[42]  
Principal amount $ 103,800,000 [7],[13],[36]             $ 69,400,000 [14],[37],[42]              
Amortized Cost 100,700,000 [7],[36]             66,100,000 [37],[42]              
Fair Value $ (103,400,000) [4],[7],[36]             $ (68,700,000) [1],[37],[42]              
Investment, Identifier [Axis]: Individual FoodService, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Principal amount $ 4,800,000 [13],[19]             $ 5,200,000 [11],[14]              
Amortized Cost 4,700,000 [19]             5,200,000 [11]              
Fair Value $ (4,700,000) [4],[19]             $ (5,200,000) [1],[11]              
Investment, Identifier [Axis]: Individual FoodService, Capital Goods 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [8],[11],[42] 6.25% [8],[11],[42] 6.25% [8],[11],[42] 6.25% [8],[11],[42] 6.25% [8],[11],[42] 6.25% [8],[11],[42] 6.25% [8],[11],[42]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42]  
Principal amount $ 1,100,000 [13],[19]             $ 16,700,000 [11],[14],[42]              
Amortized Cost 1,100,000 [19]             16,700,000 [11],[42]              
Fair Value $ (1,100,000) [4],[19]             $ (16,600,000) [1],[11],[42]              
Investment, Identifier [Axis]: Individual FoodService, Capital Goods 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base Rate Floor [11]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [11],[14]               $ 5,400,000              
Amortized Cost [11]               5,400,000              
Fair Value [1],[11]               $ (5,400,000)              
Investment, Identifier [Axis]: Individual FoodService, Capital Goods 5                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base Rate Floor [11]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [11],[14]               $ 6,900,000              
Amortized Cost [11]               6,900,000              
Fair Value [1],[11]               $ (6,800,000)              
Investment, Identifier [Axis]: Individual FoodService, Capital Goods 6                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[18]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base Rate Floor [18]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [14],[18]               $ 4,800,000              
Amortized Cost [18]               4,700,000              
Fair Value [1],[18]               $ (4,700,000)              
Investment, Identifier [Axis]: Individual FoodService, Capital Goods 7                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[18]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base Rate Floor [18]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [14],[18]               $ 1,400,000              
Amortized Cost [18]               1,400,000              
Fair Value [1],[18]               $ (1,400,000)              
Investment, Identifier [Axis]: Industria Chimica Emiliana Srl, Pharmaceuticals, Biotechnology & Life Sciences                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.25% [6],[7],[33] 7.25% [6],[7],[33] 7.25% [6],[7],[33] 7.25% [6],[7],[33] 7.25% [6],[7],[33] 7.25% [6],[7],[33] 7.25% [6],[7],[33] 7.25% [8],[11],[28] 7.25% [8],[11],[28] 7.25% [8],[11],[28] 7.25% [8],[11],[28] 7.25% [8],[11],[28] 7.25% [8],[11],[28] 7.25% [8],[11],[28]  
Base Rate Floor 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28]  
Principal amount | €       € 88.8 [7],[13],[33]             € 88.8 [11],[14],[28]        
Amortized Cost $ 102,300,000 [7],[33]             $ 102,100,000 [11],[28]              
Fair Value $ (94,000,000.0) [4],[7],[33]             $ (91,300,000) [1],[11],[28]              
Investment, Identifier [Axis]: Industria Chimica Emiliana Srl, Pharmaceuticals, Biotechnology & Life Sciences | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | €       € 113.9             € 113.9        
Amortized Cost $ 125,600,000             $ 125,500,000              
Fair Value $ (120,400,000)             $ (117,100,000)              
Investment, Identifier [Axis]: Industry City TI Lessor LP, Consumer Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[36] 10.80% 10.80% 10.80% 10.80% 10.80% 10.80% 10.80%                
Rate, PIK 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [8],[11],[37] 1.00% [8],[11],[37] 1.00% [8],[11],[37] 1.00% [8],[11],[37] 1.00% [8],[11],[37] 1.00% [8],[11],[37] 1.00% [8],[11],[37]  
Rate, Max PIK 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [8],[11],[37] 1.00% [8],[11],[37] 1.00% [8],[11],[37] 1.00% [8],[11],[37] 1.00% [8],[11],[37] 1.00% [8],[11],[37] 1.00% [8],[11],[37]  
Rate, Stated interest rate [8],[11],[37]               10.80% 10.80% 10.80% 10.80% 10.80% 10.80% 10.80%  
Principal amount $ 24,500,000 [7],[13],[36]             $ 25,600,000 [11],[14],[37]              
Amortized Cost 24,500,000 [7],[36]             25,700,000 [11],[37]              
Fair Value $ (24,800,000) [4],[7],[36]             $ (26,000,000.0) [1],[11],[37]              
Investment, Identifier [Axis]: Insight Global LLC, Commercial & Professional Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 63,500,000             $ 63,700,000              
Amortized Cost 62,800,000             62,900,000              
Fair Value $ (62,000,000.0)             $ (61,800,000)              
Investment, Identifier [Axis]: Insight Global LLC, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[7],[15] 6.00% [6],[7],[15] 6.00% [6],[7],[15] 6.00% [6],[7],[15] 6.00% [6],[7],[15] 6.00% [6],[7],[15] 6.00% [6],[7],[15] 6.00% [8],[11] 6.00% [8],[11] 6.00% [8],[11] 6.00% [8],[11] 6.00% [8],[11] 6.00% [8],[11] 6.00% [8],[11]  
Base Rate Floor 0.80% [6],[7],[15] 0.80% [6],[7],[15] 0.80% [6],[7],[15] 0.80% [6],[7],[15] 0.80% [6],[7],[15] 0.80% [6],[7],[15] 0.80% [6],[7],[15] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 202,700,000 [7],[13],[15]             $ 8,400,000 [11],[14]              
Amortized Cost 201,100,000 [7],[15]             8,400,000 [11]              
Fair Value $ (197,700,000) [4],[7],[15]             $ (8,200,000) [1],[11]              
Investment, Identifier [Axis]: Insight Global LLC, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [8],[11],[12] 6.00% [8],[11],[12] 6.00% [8],[11],[12] 6.00% [8],[11],[12] 6.00% [8],[11],[12] 6.00% [8],[11],[12] 6.00% [8],[11],[12]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [11],[12] 0.80% [11],[12] 0.80% [11],[12] 0.80% [11],[12] 0.80% [11],[12] 0.80% [11],[12] 0.80% [11],[12]  
Principal amount $ 21,100,000 [13],[19]             $ 203,300,000 [11],[12],[14]              
Amortized Cost 21,100,000 [19]             201,500,000 [11],[12]              
Fair Value $ (20,500,000) [4],[19]             $ (197,000,000.0) [1],[11],[12]              
Investment, Identifier [Axis]: Insight Global LLC, Commercial & Professional Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 26,800,000 [13],[19]             $ 12,600,000 [14],[18]              
Amortized Cost 26,800,000 [19]             12,600,000 [18]              
Fair Value $ (26,200,000) [4],[19]             $ (12,200,000) [1],[18]              
Investment, Identifier [Axis]: Insight Global LLC, Commercial & Professional Services 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[18]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base Rate Floor [18]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [14],[18]               $ 26,800,000              
Amortized Cost [18]               26,800,000              
Fair Value [1],[18]               $ (26,000,000.0)              
Investment, Identifier [Axis]: Integrity Marketing Group LLC, Insurance                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.02% [6],[7] 6.02% [6],[7] 6.02% [6],[7] 6.02% [6],[7] 6.02% [6],[7] 6.02% [6],[7] 6.02% [6],[7] 6.02% [8],[11] 6.02% [8],[11] 6.02% [8],[11] 6.02% [8],[11] 6.02% [8],[11] 6.02% [8],[11] 6.02% [8],[11]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 124,100,000 [7],[13]             $ 124,400,000 [11],[14]              
Amortized Cost 124,100,000 [7]             124,400,000 [11]              
Fair Value $ (122,500,000) [4],[7]             $ (122,400,000) [1],[11]              
Investment, Identifier [Axis]: J S Held LLC, Insurance 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[7],[15],[20],[36] 5.50% [6],[7],[15],[20],[36] 5.50% [6],[7],[15],[20],[36] 5.50% [6],[7],[15],[20],[36] 5.50% [6],[7],[15],[20],[36] 5.50% [6],[7],[15],[20],[36] 5.50% [6],[7],[15],[20],[36] 5.50% [8],[11],[12],[22],[37],[42] 5.50% [8],[11],[12],[22],[37],[42] 5.50% [8],[11],[12],[22],[37],[42] 5.50% [8],[11],[12],[22],[37],[42] 5.50% [8],[11],[12],[22],[37],[42] 5.50% [8],[11],[12],[22],[37],[42] 5.50% [8],[11],[12],[22],[37],[42]  
Base Rate Floor 1.00% [6],[7],[15],[20],[36] 1.00% [6],[7],[15],[20],[36] 1.00% [6],[7],[15],[20],[36] 1.00% [6],[7],[15],[20],[36] 1.00% [6],[7],[15],[20],[36] 1.00% [6],[7],[15],[20],[36] 1.00% [6],[7],[15],[20],[36] 1.00% [11],[12],[22],[37],[42] 1.00% [11],[12],[22],[37],[42] 1.00% [11],[12],[22],[37],[42] 1.00% [11],[12],[22],[37],[42] 1.00% [11],[12],[22],[37],[42] 1.00% [11],[12],[22],[37],[42] 1.00% [11],[12],[22],[37],[42]  
Principal amount $ 124,900,000 [7],[13],[15],[20],[36]             $ 103,000,000.0 [11],[12],[14],[22],[37],[42]              
Amortized Cost 123,000,000.0 [7],[15],[20],[36]             101,000,000.0 [11],[12],[22],[37],[42]              
Fair Value $ (122,800,000) [4],[7],[15],[20],[36]             $ (101,800,000) [1],[11],[12],[22],[37],[42]              
Investment, Identifier [Axis]: J S Held LLC, Insurance 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Principal amount $ 12,800,000 [7],[13]             $ 8,900,000 [11],[14]              
Amortized Cost 12,700,000 [7]             8,700,000 [11]              
Fair Value $ (12,600,000) [4],[7]             $ (8,800,000) [1],[11]              
Investment, Identifier [Axis]: J S Held LLC, Insurance 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[7],[20] 5.50% [6],[7],[20] 5.50% [6],[7],[20] 5.50% [6],[7],[20] 5.50% [6],[7],[20] 5.50% [6],[7],[20] 5.50% [6],[7],[20] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11] 5.50% [8],[11]  
Base Rate Floor 1.00% [6],[7],[20] 1.00% [6],[7],[20] 1.00% [6],[7],[20] 1.00% [6],[7],[20] 1.00% [6],[7],[20] 1.00% [6],[7],[20] 1.00% [6],[7],[20] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Principal amount $ 26,600,000 [7],[13],[20]             $ 22,200,000 [11],[14]              
Amortized Cost 26,600,000 [7],[20]             22,200,000 [11]              
Fair Value $ (26,200,000) [4],[7],[20]             $ (22,000,000.0) [1],[11]              
Investment, Identifier [Axis]: J S Held LLC, Insurance 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [8],[11],[22] 5.50% [8],[11],[22] 5.50% [8],[11],[22] 5.50% [8],[11],[22] 5.50% [8],[11],[22] 5.50% [8],[11],[22] 5.50% [8],[11],[22]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [11],[22] 1.00% [11],[22] 1.00% [11],[22] 1.00% [11],[22] 1.00% [11],[22] 1.00% [11],[22] 1.00% [11],[22]  
Principal amount $ 1,300,000 [13],[19]             $ 24,800,000 [11],[14],[22]              
Amortized Cost 1,300,000 [19]             24,800,000 [11],[22]              
Fair Value $ (1,200,000) [4],[19]             $ (24,600,000) [1],[11],[22]              
Investment, Identifier [Axis]: J S Held LLC, Insurance 5                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 17,400,000 [13],[19]             $ 5,200,000 [14],[18]              
Amortized Cost 17,400,000 [19]             5,200,000 [18]              
Fair Value (17,100,000) [4],[19]             $ (5,200,000) [1],[18]              
Investment, Identifier [Axis]: J S Held LLC, Insurance 6                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[18]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base Rate Floor [18]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [14],[18]               $ 19,200,000              
Amortized Cost [18]               19,200,000              
Fair Value [1],[18]               (19,000,000.0)              
Investment, Identifier [Axis]: JW Aluminum Co                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value (77,000,000.0)             (78,100,000)             (81,000,000.0)
Investment, Identifier [Axis]: JW Aluminum Co, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (2,400,000)             $ (2,400,000)             0
Investment, Identifier [Axis]: JW Aluminum Co, Common Stock, Materials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 2,105 [7],[32],[34],[53],[55] 2,105 [7],[32],[34],[53],[55] 2,105 [7],[32],[34],[53],[55] 2,105 [7],[32],[34],[53],[55] 2,105 [7],[32],[34],[53],[55] 2,105 [7],[32],[34],[53],[55] 2,105 [7],[32],[34],[53],[55] 2,105 [11],[27],[35],[56] 2,105 [11],[27],[35],[56] 2,105 [11],[27],[35],[56] 2,105 [11],[27],[35],[56] 2,105 [11],[27],[35],[56] 2,105 [11],[27],[35],[56] 2,105 [11],[27],[35],[56]  
Amortized Cost $ 0 [7],[32],[34],[53],[55]             $ 0.0 [11],[27],[35],[56]              
Fair Value $ (2,400,000) [4],[7],[32],[34],[53],[55]             $ (2,400,000) [1],[11],[27],[35],[56]              
Investment, Identifier [Axis]: JW Aluminum Co, Materials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[34],[36],[39] 10.30% 10.30% 10.30% 10.30% 10.30% 10.30% 10.30%                
Rate, Stated interest rate [8],[11],[35],[37],[40]               10.30% 10.30% 10.30% 10.30% 10.30% 10.30% 10.30%  
Principal amount $ 76,500,000 [7],[13],[34],[36],[39]             $ 76,500,000 [11],[14],[35],[37],[40]              
Amortized Cost 75,800,000 [7],[34],[36],[39]             75,700,000 [11],[35],[37],[40]              
Fair Value (77,000,000.0) [4],[7],[34],[36],[39]             (78,100,000) [1],[11],[35],[37],[40]              
Investment, Identifier [Axis]: JW Aluminum Co, Preferred Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (147,900,000)             $ (112,500,000)             (122,600,000)
Investment, Identifier [Axis]: JW Aluminum Co, Preferred Stock, Materials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 6.30% [6],[7],[34],[53],[55] 6.30% [6],[7],[34],[53],[55] 6.30% [6],[7],[34],[53],[55] 6.30% [6],[7],[34],[53],[55] 6.30% [6],[7],[34],[53],[55] 6.30% [6],[7],[34],[53],[55] 6.30% [6],[7],[34],[53],[55] 6.30% 6.30% 6.30% 6.30% 6.30% 6.30% 6.30%  
Rate, Max PIK 12.50% [6],[7],[34],[53],[55] 12.50% [6],[7],[34],[53],[55] 12.50% [6],[7],[34],[53],[55] 12.50% [6],[7],[34],[53],[55] 12.50% [6],[7],[34],[53],[55] 12.50% [6],[7],[34],[53],[55] 12.50% [6],[7],[34],[53],[55] 12.50% 12.50% 12.50% 12.50% 12.50% 12.50% 12.50%  
Number of Shares | shares 15,279 [7],[34],[53],[55] 15,279 [7],[34],[53],[55] 15,279 [7],[34],[53],[55] 15,279 [7],[34],[53],[55] 15,279 [7],[34],[53],[55] 15,279 [7],[34],[53],[55] 15,279 [7],[34],[53],[55] 15,279 [11],[27],[35] 15,279 [11],[27],[35] 15,279 [11],[27],[35] 15,279 [11],[27],[35] 15,279 [11],[27],[35] 15,279 [11],[27],[35] 15,279 [11],[27],[35]  
Amortized Cost $ 204,600,000 [7],[34],[53],[55]             $ 200,100,000 [11],[27],[35]              
Fair Value $ (147,900,000) [4],[7],[34],[53],[55]             $ (112,500,000) [1],[11],[27],[35]              
Investment, Identifier [Axis]: Jarrow Formulas Inc, Household & Personal Products                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[7],[15],[16],[17],[20],[21],[36],[41] 6.25% [6],[7],[15],[16],[17],[20],[21],[36],[41] 6.25% [6],[7],[15],[16],[17],[20],[21],[36],[41] 6.25% [6],[7],[15],[16],[17],[20],[21],[36],[41] 6.25% [6],[7],[15],[16],[17],[20],[21],[36],[41] 6.25% [6],[7],[15],[16],[17],[20],[21],[36],[41] 6.25% [6],[7],[15],[16],[17],[20],[21],[36],[41] 6.25% [8],[9],[10],[11],[12],[22],[23],[37],[42] 6.25% [8],[9],[10],[11],[12],[22],[23],[37],[42] 6.25% [8],[9],[10],[11],[12],[22],[23],[37],[42] 6.25% [8],[9],[10],[11],[12],[22],[23],[37],[42] 6.25% [8],[9],[10],[11],[12],[22],[23],[37],[42] 6.25% [8],[9],[10],[11],[12],[22],[23],[37],[42] 6.25% [8],[9],[10],[11],[12],[22],[23],[37],[42]  
Base Rate Floor 1.00% [6],[7],[15],[16],[17],[20],[21],[36],[41] 1.00% [6],[7],[15],[16],[17],[20],[21],[36],[41] 1.00% [6],[7],[15],[16],[17],[20],[21],[36],[41] 1.00% [6],[7],[15],[16],[17],[20],[21],[36],[41] 1.00% [6],[7],[15],[16],[17],[20],[21],[36],[41] 1.00% [6],[7],[15],[16],[17],[20],[21],[36],[41] 1.00% [6],[7],[15],[16],[17],[20],[21],[36],[41] 1.00% [9],[10],[11],[12],[22],[23],[37],[42] 1.00% [9],[10],[11],[12],[22],[23],[37],[42] 1.00% [9],[10],[11],[12],[22],[23],[37],[42] 1.00% [9],[10],[11],[12],[22],[23],[37],[42] 1.00% [9],[10],[11],[12],[22],[23],[37],[42] 1.00% [9],[10],[11],[12],[22],[23],[37],[42] 1.00% [9],[10],[11],[12],[22],[23],[37],[42]  
Principal amount $ 180,600,000 [7],[13],[15],[16],[17],[20],[21],[36],[41]             $ 181,800,000 [9],[10],[11],[12],[14],[22],[23],[37],[42]              
Amortized Cost 173,300,000 [7],[15],[16],[17],[20],[21],[36],[41]             174,100,000 [9],[10],[11],[12],[22],[23],[37],[42]              
Fair Value $ (177,900,000) [4],[7],[15],[16],[17],[20],[21],[36],[41]             (181,300,000) [1],[9],[10],[11],[12],[22],[23],[37],[42]              
Investment, Identifier [Axis]: Jet Edge International LLC, Term Loan , Asset Based Finance                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ 0             (75,600,000)
Investment, Identifier [Axis]: Jet Edge International LLC, Term Loan, Transportation 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 2.00% [6],[7] 2.00% [6],[7] 2.00% [6],[7] 2.00% [6],[7] 2.00% [6],[7] 2.00% [6],[7] 2.00% [6],[7] 2.00% [11] 2.00% [11] 2.00% [11] 2.00% [11] 2.00% [11] 2.00% [11] 2.00% [11]  
Rate, Max PIK 2.00% [6],[7] 2.00% [6],[7] 2.00% [6],[7] 2.00% [6],[7] 2.00% [6],[7] 2.00% [6],[7] 2.00% [6],[7] 2.00% [11] 2.00% [11] 2.00% [11] 2.00% [11] 2.00% [11] 2.00% [11] 2.00% [11]  
Rate, Stated interest rate 10.00% [6],[7] 10.00% [6],[7] 10.00% [6],[7] 10.00% [6],[7] 10.00% [6],[7] 10.00% [6],[7] 10.00% [6],[7] 10.00% [11] 10.00% [11] 10.00% [11] 10.00% [11] 10.00% [11] 10.00% [11] 10.00% [11]  
Principal amount $ 72,000,000.0 [7],[13]             $ 74,500,000 [11],[14]              
Amortized Cost 72,000,000.0 [7]             74,500,000 [11]              
Fair Value $ (74,200,000) [4],[7]             $ (76,700,000) [1],[11]              
Investment, Identifier [Axis]: Jet Edge International LLC, Term Loan, Transportation 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 2.00% [6],[19] 2.00% [6],[19] 2.00% [6],[19] 2.00% [6],[19] 2.00% [6],[19] 2.00% [6],[19] 2.00% [6],[19] 2.00% [18] 2.00% [18] 2.00% [18] 2.00% [18] 2.00% [18] 2.00% [18] 2.00% [18]  
Rate, Max PIK 2.00% [6],[19] 2.00% [6],[19] 2.00% [6],[19] 2.00% [6],[19] 2.00% [6],[19] 2.00% [6],[19] 2.00% [6],[19] 2.00% [18] 2.00% [18] 2.00% [18] 2.00% [18] 2.00% [18] 2.00% [18] 2.00% [18]  
Rate, Stated interest rate 10.00% [6],[19] 10.00% [6],[19] 10.00% [6],[19] 10.00% [6],[19] 10.00% [6],[19] 10.00% [6],[19] 10.00% [6],[19] 10.00% [18] 10.00% [18] 10.00% [18] 10.00% [18] 10.00% [18] 10.00% [18] 10.00% [18]  
Principal amount $ 700,000 [13],[19]             $ 700,000 [14],[18]              
Amortized Cost 700,000 [19]             700,000 [18]              
Fair Value $ (700,000) [4],[19]             (700,000) [1],[18]              
Investment, Identifier [Axis]: Jet Edge International LLC, Warrant, Asset Based Finance                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ 0             (4,500,000)
Investment, Identifier [Axis]: Jones Apparel Holdings, Inc., Common Stock, Consumer Durables & Apparel                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[32] 5,451 5,451 5,451 5,451 5,451 5,451 5,451 5,451 5,451 5,451 5,451 5,451 5,451 5,451  
Amortized Cost [7],[32] $ 900,000             $ 900,000              
Fair Value [7],[32] $ 0 [4]             $ 0 [1]              
Investment, Identifier [Axis]: KBP Investments LLC, Consumer Staples Distribution & Retail 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Rate, PIK 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Rate, Max PIK 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount $ 14,600,000                            
Amortized Cost 14,600,000                            
Fair Value $ (13,500,000)                            
Investment, Identifier [Axis]: KBP Investments LLC, Consumer Staples Distribution & Retail 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Rate, PIK 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Rate, Max PIK 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount $ 9,000,000.0                            
Amortized Cost 9,000,000.0                            
Fair Value (8,400,000)                            
Investment, Identifier [Axis]: KBP Investments LLC, Food & Staples Retailing | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Rate, PIK               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Rate, Max PIK               0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Base Rate Floor               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount               $ 23,600,000              
Amortized Cost               23,500,000              
Fair Value               (21,900,000)              
Investment, Identifier [Axis]: KKR Altitude II Offshore Aggregator LP, Partnership Interest                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (49,800,000)             $ (44,400,000)             0
Investment, Identifier [Axis]: KKR Altitude II Offshore Aggregator LP, Partnership Interest, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 49,011,924 [7],[13],[32],[33],[34] 49,011,924 [7],[13],[32],[33],[34] 49,011,924 [7],[13],[32],[33],[34] 49,011,924 [7],[13],[32],[33],[34] 49,011,924 [7],[13],[32],[33],[34] 49,011,924 [7],[13],[32],[33],[34] 49,011,924 [7],[13],[32],[33],[34] 44,424,346 [11],[14],[27],[28],[35] 44,424,346 [11],[14],[27],[28],[35] 44,424,346 [11],[14],[27],[28],[35] 44,424,346 [11],[14],[27],[28],[35] 44,424,346 [11],[14],[27],[28],[35] 44,424,346 [11],[14],[27],[28],[35] 44,424,346 [11],[14],[27],[28],[35]  
Amortized Cost $ 49,000,000.0 [7],[32],[33],[34]             $ 44,400,000 [11],[27],[28],[35]              
Fair Value $ (49,800,000) [4],[7],[32],[33],[34]             $ (44,400,000) [1],[11],[27],[28],[35]              
Investment, Identifier [Axis]: KKR Central Park Leasing Aggregator L.P., Partnership Interest, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate 14.30% [6],[7],[29],[32],[33] 14.30% [6],[7],[29],[32],[33] 14.30% [6],[7],[29],[32],[33] 14.30% [6],[7],[29],[32],[33] 14.30% [6],[7],[29],[32],[33] 14.30% [6],[7],[29],[32],[33] 14.30% [6],[7],[29],[32],[33] 14.30% [11],[24],[27],[28] 14.30% [11],[24],[27],[28] 14.30% [11],[24],[27],[28] 14.30% [11],[24],[27],[28] 14.30% [11],[24],[27],[28] 14.30% [11],[24],[27],[28] 14.30% [11],[24],[27],[28]  
Principal amount $ 39,100,000 [7],[13],[29],[32],[33]             $ 39,100,000 [11],[14],[24],[27],[28]              
Amortized Cost 39,100,000 [7],[29],[32],[33]             39,100,000 [11],[24],[27],[28]              
Fair Value $ (16,200,000) [4],[7],[29],[32],[33]             $ (16,300,000) [1],[11],[24],[27],[28]              
Investment, Identifier [Axis]: KKR Chord IP Aggregator LP, Partnership Interest, Media & Entertainment                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 89,453,083 [7],[13],[33] 89,453,083 [7],[13],[33] 89,453,083 [7],[13],[33] 89,453,083 [7],[13],[33] 89,453,083 [7],[13],[33] 89,453,083 [7],[13],[33] 89,453,083 [7],[13],[33] 89,453,083 [11],[14],[28] 89,453,083 [11],[14],[28] 89,453,083 [11],[14],[28] 89,453,083 [11],[14],[28] 89,453,083 [11],[14],[28] 89,453,083 [11],[14],[28] 89,453,083 [11],[14],[28]  
Amortized Cost $ 89,500,000 [7],[33]             $ 89,500,000 [11],[28]              
Fair Value $ (98,700,000) [4],[7],[33]             $ (96,300,000) [1],[11],[28]              
Investment, Identifier [Axis]: KKR Chord IP Aggregator LP, Partnership Interest, Media & Entertainment | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 19,616,330 19,616,330 19,616,330 19,616,330 19,616,330 19,616,330 19,616,330 19,616,330 19,616,330 19,616,330 19,616,330 19,616,330 19,616,330 19,616,330  
Amortized Cost $ 22,900,000             $ 22,900,000              
Fair Value $ (21,700,000)             $ (21,100,000)              
Investment, Identifier [Axis]: KKR Residential Opportunities I LLC, Private Equity, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [11],[14],[27]               17,510,867 17,510,867 17,510,867 17,510,867 17,510,867 17,510,867 17,510,867  
Amortized Cost [11],[27]               $ 17,500,000              
Fair Value [1],[11],[27]               (17,600,000)              
Investment, Identifier [Axis]: KKR Residential Opportunities I LLC, Private Equity, Real Estate Management & Development                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[13],[32] 19,576,347 19,576,347 19,576,347 19,576,347 19,576,347 19,576,347 19,576,347                
Amortized Cost [7],[32] $ 19,600,000                            
Fair Value [4],[7],[32] (20,400,000)                            
Investment, Identifier [Axis]: KKR Rocket Loans Aggregator LLC, Partnership Interest                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (13,900,000)             $ (4,300,000)             (1,400,000)
Investment, Identifier [Axis]: KKR Rocket Loans Aggregator LLC, Partnership Interest, Diversified Financials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [11],[14],[28],[35]               4,336,415 4,336,415 4,336,415 4,336,415 4,336,415 4,336,415 4,336,415  
Amortized Cost [11],[28],[35]               $ 4,300,000              
Fair Value [1],[11],[28],[35]               $ (4,300,000)              
Investment, Identifier [Axis]: KKR Rocket Loans Aggregator LLC, Partnership Interest, Financial Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[13],[33],[34] 14,180,166 14,180,166 14,180,166 14,180,166 14,180,166 14,180,166 14,180,166                
Amortized Cost [7],[33],[34] $ 14,200,000                            
Fair Value [4],[7],[33],[34] $ (13,900,000)                            
Investment, Identifier [Axis]: KKR Zeno Aggregator LP (K2 Aviation), Partnership Interest, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 23,664,954 [7],[13],[32],[33] 23,664,954 [7],[13],[32],[33] 23,664,954 [7],[13],[32],[33] 23,664,954 [7],[13],[32],[33] 23,664,954 [7],[13],[32],[33] 23,664,954 [7],[13],[32],[33] 23,664,954 [7],[13],[32],[33] 23,664,954 [11],[14],[27],[28] 23,664,954 [11],[14],[27],[28] 23,664,954 [11],[14],[27],[28] 23,664,954 [11],[14],[27],[28] 23,664,954 [11],[14],[27],[28] 23,664,954 [11],[14],[27],[28] 23,664,954 [11],[14],[27],[28]  
Amortized Cost $ 23,000,000.0 [7],[32],[33]             $ 23,000,000.0 [11],[27],[28]              
Fair Value $ (20,600,000) [4],[7],[32],[33]             $ (20,000,000.0) [1],[11],[27],[28]              
Investment, Identifier [Axis]: KKR Zeno Aggregator LP (K2 Aviation), Partnership Interest, Capital Goods | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 19,642,734 19,642,734 19,642,734 19,642,734 19,642,734 19,642,734 19,642,734 19,642,734 19,642,734 19,642,734 19,642,734 19,642,734 19,642,734 19,642,734  
Amortized Cost $ 24,400,000             $ 24,400,000              
Fair Value $ (17,100,000)             $ (16,600,000)              
Investment, Identifier [Axis]: Karman Space Inc, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.00% [6],[7] 7.00% [6],[7] 7.00% [6],[7] 7.00% [6],[7] 7.00% [6],[7] 7.00% [6],[7] 7.00% [6],[7] 7.00% [8],[11],[42] 7.00% [8],[11],[42] 7.00% [8],[11],[42] 7.00% [8],[11],[42] 7.00% [8],[11],[42] 7.00% [8],[11],[42] 7.00% [8],[11],[42]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42]  
Principal amount $ 87,700,000 [7],[13]             $ 51,100,000 [11],[14],[42]              
Amortized Cost 85,100,000 [7]             48,900,000 [11],[42]              
Fair Value $ (86,100,000) [4],[7]             $ (49,700,000) [1],[11],[42]              
Investment, Identifier [Axis]: Karman Space Inc, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.00% [6],[7] 7.00% [6],[7] 7.00% [6],[7] 7.00% [6],[7] 7.00% [6],[7] 7.00% [6],[7] 7.00% [6],[7] 7.00% [8],[11] 7.00% [8],[11] 7.00% [8],[11] 7.00% [8],[11] 7.00% [8],[11] 7.00% [8],[11] 7.00% [8],[11]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Principal amount $ 4,700,000 [7],[13]             $ 4,500,000 [11],[14]              
Amortized Cost 4,500,000 [7]             4,300,000 [11]              
Fair Value $ (4,600,000) [4],[7]             $ (4,400,000) [1],[11]              
Investment, Identifier [Axis]: Karman Space Inc, Capital Goods 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.00% [6],[19] 7.00% [6],[19] 7.00% [6],[19] 7.00% [6],[19] 7.00% [6],[19] 7.00% [6],[19] 7.00% [6],[19] 7.00% [8],[11] 7.00% [8],[11] 7.00% [8],[11] 7.00% [8],[11] 7.00% [8],[11] 7.00% [8],[11] 7.00% [8],[11]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Principal amount $ 800,000 [13],[19]             $ 37,100,000 [11],[14]              
Amortized Cost 800,000 [19]             36,600,000 [11]              
Fair Value $ (800,000) [4],[19]             $ (36,100,000) [1],[11]              
Investment, Identifier [Axis]: Karman Space Inc, Capital Goods 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[18]               7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%  
Base Rate Floor [18]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [14],[18]               $ 1,000,000.0              
Amortized Cost [18]               1,000,000.0              
Fair Value [1],[18]               $ (900,000)              
Investment, Identifier [Axis]: Kellermeyer Bergensons Services LLC, Commercial & Professional Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[15],[16],[17],[20],[21],[36],[41] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base Rate Floor [6],[7],[15],[16],[17],[20],[21],[36],[41] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [7],[13],[15],[16],[17],[20],[21],[36],[41] $ 368,000,000.0                            
Amortized Cost [7],[15],[16],[17],[20],[21],[36],[41] 358,500,000                            
Fair Value [4],[7],[15],[16],[17],[20],[21],[36],[41] $ (339,200,000)                            
Investment, Identifier [Axis]: Kellermeyer Bergensons Services LLC, Commercial & Professional Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 29,100,000             $ 29,200,000              
Amortized Cost 28,100,000             28,100,000              
Fair Value (26,800,000)             $ (26,500,000)              
Investment, Identifier [Axis]: Kellermeyer Bergensons Services LLC, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[9],[10],[11],[12],[22],[23],[37],[42]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base Rate Floor [9],[10],[11],[12],[22],[23],[37],[42]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [9],[10],[11],[12],[14],[22],[23],[37],[42]               $ 268,900,000              
Amortized Cost [9],[10],[11],[12],[22],[23],[37],[42]               259,500,000              
Fair Value [1],[9],[10],[11],[12],[22],[23],[37],[42]               $ (244,600,000)              
Investment, Identifier [Axis]: Kellermeyer Bergensons Services LLC, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base Rate Floor [11]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [11],[14]               $ 84,600,000              
Amortized Cost [11]               84,100,000              
Fair Value [1],[11]               $ (77,000,000.0)              
Investment, Identifier [Axis]: Kellermeyer Bergensons Services LLC, Commercial & Professional Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base Rate Floor [11]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [11],[14]               $ 15,400,000              
Amortized Cost [11]               15,300,000              
Fair Value [1],[11]               (14,000,000.0)              
Investment, Identifier [Axis]: Kilter Finance, Preferred Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (99,400,000)             $ (99,500,000)             (36,100,000)
Investment, Identifier [Axis]: Kilter Finance, Preferred Stock, Insurance                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate 12.00% [6],[7],[33],[34] 12.00% [6],[7],[33],[34] 12.00% [6],[7],[33],[34] 12.00% [6],[7],[33],[34] 12.00% [6],[7],[33],[34] 12.00% [6],[7],[33],[34] 12.00% [6],[7],[33],[34] 12.00% [11],[28],[35] 12.00% [11],[28],[35] 12.00% [11],[28],[35] 12.00% [11],[28],[35] 12.00% [11],[28],[35] 12.00% [11],[28],[35] 12.00% [11],[28],[35]  
Principal amount $ 99,400,000 [7],[13],[33],[34]             $ 99,400,000 [11],[14],[28],[35]              
Amortized Cost 98,600,000 [7],[33],[34]             98,600,000 [11],[28],[35]              
Fair Value $ (99,400,000) [4],[7],[33],[34]             $ (99,500,000) [1],[11],[28],[35]              
Investment, Identifier [Axis]: Kilter Finance, Preferred Stock, Insurance | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate 12.00% 12.00% 12.00% 12.00% 12.00% 12.00% 12.00% 12.00% 12.00% 12.00% 12.00% 12.00% 12.00% 12.00%  
Principal amount $ 24,000,000.0             $ 24,000,000.0              
Amortized Cost 24,000,000.0             24,000,000.0              
Fair Value (24,000,000.0)             (24,000,000.0)              
Investment, Identifier [Axis]: Kilter Finance, Private Equity                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (500,000)             $ (500,000)             (500,000)
Investment, Identifier [Axis]: Kilter Finance, Private Equity, Insurance                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 536,709 [7],[13],[32],[33],[34] 536,709 [7],[13],[32],[33],[34] 536,709 [7],[13],[32],[33],[34] 536,709 [7],[13],[32],[33],[34] 536,709 [7],[13],[32],[33],[34] 536,709 [7],[13],[32],[33],[34] 536,709 [7],[13],[32],[33],[34] 536,709 [11],[14],[27],[28],[35] 536,709 [11],[14],[27],[28],[35] 536,709 [11],[14],[27],[28],[35] 536,709 [11],[14],[27],[28],[35] 536,709 [11],[14],[27],[28],[35] 536,709 [11],[14],[27],[28],[35] 536,709 [11],[14],[27],[28],[35]  
Amortized Cost $ 500,000 [7],[32],[33],[34]             $ 500,000 [11],[27],[28],[35]              
Fair Value $ (500,000) [4],[7],[32],[33],[34]             $ (500,000) [1],[11],[27],[28],[35]              
Investment, Identifier [Axis]: Laboratoires Vivacy SAS, Pharmaceuticals, Biotechnology & Life Sciences 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[33] 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%                
Rate, PIK [6],[7],[33] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Rate, Max PIK [6],[7],[33] 2.40% 2.40% 2.40% 2.40% 2.40% 2.40% 2.40%                
Base Rate Floor [6],[7],[33] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | € [7],[13],[33]       € 7.8                      
Amortized Cost [7],[33] $ 8,000,000.0                            
Fair Value [4],[7],[33] $ (8,100,000)                            
Investment, Identifier [Axis]: Laboratoires Vivacy SAS, Pharmaceuticals, Biotechnology & Life Sciences 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19],[33] 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%                
Rate, PIK [6],[19],[33] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Rate, Max PIK [6],[19],[33] 2.40% 2.40% 2.40% 2.40% 2.40% 2.40% 2.40%                
Base Rate Floor [6],[19],[33] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | € [13],[19],[33]       € 0.6                      
Amortized Cost [19],[33] $ 700,000                            
Fair Value [4],[19],[33] $ (600,000)                            
Investment, Identifier [Axis]: Lakefield Veterinary Group, Health Care Equipment & Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 27,000,000.0             $ 27,100,000              
Amortized Cost 26,700,000             26,700,000              
Fair Value $ (26,000,000.0)             $ (25,900,000)              
Investment, Identifier [Axis]: Lakefield Veterinary Group, Health Care Equipment & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[7],[15],[20],[41] 5.50% [6],[7],[15],[20],[41] 5.50% [6],[7],[15],[20],[41] 5.50% [6],[7],[15],[20],[41] 5.50% [6],[7],[15],[20],[41] 5.50% [6],[7],[15],[20],[41] 5.50% [6],[7],[15],[20],[41] 5.50% [8],[11],[12],[22] 5.50% [8],[11],[12],[22] 5.50% [8],[11],[12],[22] 5.50% [8],[11],[12],[22] 5.50% [8],[11],[12],[22] 5.50% [8],[11],[12],[22] 5.50% [8],[11],[12],[22]  
Base Rate Floor 0.80% [6],[7],[15],[20],[41] 0.80% [6],[7],[15],[20],[41] 0.80% [6],[7],[15],[20],[41] 0.80% [6],[7],[15],[20],[41] 0.80% [6],[7],[15],[20],[41] 0.80% [6],[7],[15],[20],[41] 0.80% [6],[7],[15],[20],[41] 0.80% [11],[12],[22] 0.80% [11],[12],[22] 0.80% [11],[12],[22] 0.80% [11],[12],[22] 0.80% [11],[12],[22] 0.80% [11],[12],[22] 0.80% [11],[12],[22]  
Principal amount $ 108,900,000 [7],[13],[15],[20],[41]             $ 108,300,000 [11],[12],[14],[22]              
Amortized Cost 108,200,000 [7],[15],[20],[41]             107,600,000 [11],[12],[22]              
Fair Value $ (104,600,000) [4],[7],[15],[20],[41]             $ (103,800,000) [1],[11],[12],[22]              
Investment, Identifier [Axis]: Lakefield Veterinary Group, Health Care Equipment & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 34,300,000 [13],[19]             $ 35,200,000 [14],[18]              
Amortized Cost 34,300,000 [19]             35,200,000 [18]              
Fair Value $ (33,000,000.0) [4],[19]             $ (33,700,000) [1],[18]              
Investment, Identifier [Axis]: Lakeview Farms Inc, Food, Beverage & Tobacco | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 15,500,000             $ 15,500,000              
Amortized Cost 15,400,000             15,400,000              
Fair Value $ (15,000,000.0)             $ (15,000,000.0)              
Investment, Identifier [Axis]: Lakeview Farms Inc, Food, Beverage & Tobacco 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[7],[17],[41] 6.25% [6],[7],[17],[41] 6.25% [6],[7],[17],[41] 6.25% [6],[7],[17],[41] 6.25% [6],[7],[17],[41] 6.25% [6],[7],[17],[41] 6.25% [6],[7],[17],[41] 6.25% [8],[10],[42] 6.25% [8],[10],[42] 6.25% [8],[10],[42] 6.25% [8],[10],[42] 6.25% [8],[10],[42] 6.25% [8],[10],[42] 6.25% [8],[10],[42]  
Base Rate Floor 1.00% [6],[7],[17],[41] 1.00% [6],[7],[17],[41] 1.00% [6],[7],[17],[41] 1.00% [6],[7],[17],[41] 1.00% [6],[7],[17],[41] 1.00% [6],[7],[17],[41] 1.00% [6],[7],[17],[41] 1.00% [10],[42] 1.00% [10],[42] 1.00% [10],[42] 1.00% [10],[42] 1.00% [10],[42] 1.00% [10],[42] 1.00% [10],[42]  
Principal amount $ 76,000,000.0 [7],[13],[17],[41]             $ 31,200,000 [10],[14],[42]              
Amortized Cost 74,500,000 [7],[17],[41]             29,600,000 [10],[42]              
Fair Value $ (73,800,000) [4],[7],[17],[41]             $ (30,200,000) [1],[10],[42]              
Investment, Identifier [Axis]: Lakeview Farms Inc, Food, Beverage & Tobacco 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Principal amount $ 3,900,000 [7],[13]             $ 4,500,000 [11],[14]              
Amortized Cost 3,900,000 [7]             4,500,000 [11]              
Fair Value $ (3,800,000) [4],[7]             $ (4,300,000) [1],[11]              
Investment, Identifier [Axis]: Lakeview Farms Inc, Food, Beverage & Tobacco 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [8],[11],[42] 6.25% [8],[11],[42] 6.25% [8],[11],[42] 6.25% [8],[11],[42] 6.25% [8],[11],[42] 6.25% [8],[11],[42] 6.25% [8],[11],[42]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42]  
Principal amount $ 10,800,000 [13],[19]             $ 45,000,000.0 [11],[14],[42]              
Amortized Cost 10,800,000 [19]             45,000,000.0 [11],[42]              
Fair Value $ (10,500,000) [4],[19]             $ (43,600,000) [1],[11],[42]              
Investment, Identifier [Axis]: Lakeview Farms Inc, Food, Beverage & Tobacco 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 2,800,000 [13],[19]             $ 10,800,000 [14],[18]              
Amortized Cost 2,800,000 [19]             10,800,000 [18]              
Fair Value (2,800,000) [4],[19]             $ (10,500,000) [1],[18]              
Investment, Identifier [Axis]: Lakeview Farms Inc, Food, Beverage & Tobacco 5                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[18]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base Rate Floor [18]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [14],[18]               $ 2,300,000              
Amortized Cost [18]               2,300,000              
Fair Value [1],[18]               (2,200,000)              
Investment, Identifier [Axis]: Largest Portfolio Company Investment | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount $ 132,400,000             $ 132,400,000              
Investment, Identifier [Axis]: Lenovo Group Ltd, Structured Mezzanine, Technology Hardware & Equipment 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 4,700,000             $ 4,700,000              
Amortized Cost 4,700,000             4,700,000              
Fair Value $ (4,700,000)             $ (4,700,000)              
Investment, Identifier [Axis]: Lenovo Group Ltd, Structured Mezzanine, Technology Hardware & Equipment 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount | €       € 3.6             € 3.6        
Amortized Cost $ 3,600,000             $ 3,600,000              
Fair Value $ (3,900,000)             $ (3,900,000)              
Investment, Identifier [Axis]: Lenovo Group Ltd, Structured Mezzanine, Technology Hardware & Equipment 3 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount | €       € 5.0             € 5.0        
Amortized Cost $ 5,000,000.0                     £ 5.0      
Fair Value $ (5,400,000)                     £ (5.4)      
Investment, Identifier [Axis]: Lenovo Group Ltd, Structured Mezzanine, Technology Hardware & Equipment 4 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount | £         £ 1.1             £ 1.1      
Amortized Cost $ 1,300,000                     1.3      
Fair Value $ (1,400,000)                     £ (1.4)      
Investment, Identifier [Axis]: Lenovo Group Ltd, Structured Mezzanine, Technology Hardware & Equipment 5 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 6,500,000             $ 6,500,000              
Amortized Cost 6,500,000             6,500,000              
Fair Value $ (6,500,000)             $ (6,500,000)              
Investment, Identifier [Axis]: Lenovo Group Ltd, Structured Mezzanine, Technology Hardware & Equipment 6 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount | £         £ 0.8             £ 0.8      
Amortized Cost $ 900,000             $ 900,000              
Fair Value $ (1,000,000.0)             $ (1,000,000.0)              
Investment, Identifier [Axis]: Lexitas Inc, Commercial & Professional Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 18,400,000             $ 18,500,000              
Amortized Cost 18,400,000             18,400,000              
Fair Value $ (18,300,000)             $ (18,200,000)              
Investment, Identifier [Axis]: Lexitas Inc, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.75% [6],[7] 6.75% [6],[7] 6.75% [6],[7] 6.75% [6],[7] 6.75% [6],[7] 6.75% [6],[7] 6.75% [6],[7] 6.75% [8],[9],[10],[11],[12],[42] 6.75% [8],[9],[10],[11],[12],[42] 6.75% [8],[9],[10],[11],[12],[42] 6.75% [8],[9],[10],[11],[12],[42] 6.75% [8],[9],[10],[11],[12],[42] 6.75% [8],[9],[10],[11],[12],[42] 6.75% [8],[9],[10],[11],[12],[42]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [9],[10],[11],[12],[42] 1.00% [9],[10],[11],[12],[42] 1.00% [9],[10],[11],[12],[42] 1.00% [9],[10],[11],[12],[42] 1.00% [9],[10],[11],[12],[42] 1.00% [9],[10],[11],[12],[42] 1.00% [9],[10],[11],[12],[42]  
Principal amount $ 800,000 [7],[13]             $ 133,100,000 [9],[10],[11],[12],[14],[42]              
Amortized Cost 800,000 [7]             130,200,000 [9],[10],[11],[12],[42]              
Fair Value $ (800,000) [4],[7]             $ (131,100,000) [1],[9],[10],[11],[12],[42]              
Investment, Identifier [Axis]: Lexitas Inc, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.75% [6],[7],[15],[16],[17],[41] 6.75% [6],[7],[15],[16],[17],[41] 6.75% [6],[7],[15],[16],[17],[41] 6.75% [6],[7],[15],[16],[17],[41] 6.75% [6],[7],[15],[16],[17],[41] 6.75% [6],[7],[15],[16],[17],[41] 6.75% [6],[7],[15],[16],[17],[41] 6.75% [8],[18] 6.75% [8],[18] 6.75% [8],[18] 6.75% [8],[18] 6.75% [8],[18] 6.75% [8],[18] 6.75% [8],[18]  
Base Rate Floor 1.00% [6],[7],[15],[16],[17],[41] 1.00% [6],[7],[15],[16],[17],[41] 1.00% [6],[7],[15],[16],[17],[41] 1.00% [6],[7],[15],[16],[17],[41] 1.00% [6],[7],[15],[16],[17],[41] 1.00% [6],[7],[15],[16],[17],[41] 1.00% [6],[7],[15],[16],[17],[41] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 132,800,000 [7],[13],[15],[16],[17],[41]             $ 8,400,000 [14],[18]              
Amortized Cost 130,000,000.0 [7],[15],[16],[17],[41]             8,400,000 [18]              
Fair Value $ (131,800,000) [4],[7],[15],[16],[17],[41]             $ (8,300,000) [1],[18]              
Investment, Identifier [Axis]: Lexitas Inc, Commercial & Professional Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19] 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%                
Base Rate Floor [6],[19] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[19] $ 7,600,000                            
Amortized Cost [19] 7,600,000                            
Fair Value [4],[19] $ (7,500,000)                            
Investment, Identifier [Axis]: Lionbridge Technologies Inc, Media & Entertainment                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.00% [6],[7],[16],[20],[21],[36] 7.00% [6],[7],[16],[20],[21],[36] 7.00% [6],[7],[16],[20],[21],[36] 7.00% [6],[7],[16],[20],[21],[36] 7.00% [6],[7],[16],[20],[21],[36] 7.00% [6],[7],[16],[20],[21],[36] 7.00% [6],[7],[16],[20],[21],[36] 7.00% [8],[9],[11],[22],[23],[37],[42] 7.00% [8],[9],[11],[22],[23],[37],[42] 7.00% [8],[9],[11],[22],[23],[37],[42] 7.00% [8],[9],[11],[22],[23],[37],[42] 7.00% [8],[9],[11],[22],[23],[37],[42] 7.00% [8],[9],[11],[22],[23],[37],[42] 7.00% [8],[9],[11],[22],[23],[37],[42]  
Base Rate Floor 1.00% [6],[7],[16],[20],[21],[36] 1.00% [6],[7],[16],[20],[21],[36] 1.00% [6],[7],[16],[20],[21],[36] 1.00% [6],[7],[16],[20],[21],[36] 1.00% [6],[7],[16],[20],[21],[36] 1.00% [6],[7],[16],[20],[21],[36] 1.00% [6],[7],[16],[20],[21],[36] 1.00% [9],[11],[22],[23],[37],[42] 1.00% [9],[11],[22],[23],[37],[42] 1.00% [9],[11],[22],[23],[37],[42] 1.00% [9],[11],[22],[23],[37],[42] 1.00% [9],[11],[22],[23],[37],[42] 1.00% [9],[11],[22],[23],[37],[42] 1.00% [9],[11],[22],[23],[37],[42]  
Principal amount $ 119,400,000 [7],[13],[16],[20],[21],[36]             $ 122,700,000 [9],[11],[14],[22],[23],[37],[42]              
Amortized Cost 116,100,000 [7],[16],[20],[21],[36]             119,000,000.0 [9],[11],[22],[23],[37],[42]              
Fair Value $ (120,200,000) [4],[7],[16],[20],[21],[36]             $ (123,400,000) [1],[9],[11],[22],[23],[37],[42]              
Investment, Identifier [Axis]: Lionbridge Technologies Inc, Media & Entertainment | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 26,100,000             $ 26,800,000              
Amortized Cost 25,600,000             26,300,000              
Fair Value $ (26,200,000)             $ (26,900,000)              
Investment, Identifier [Axis]: Lipari Foods LLC, Common Stock, Consumer Staples Distribution & Retail                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[32] 7,942,724 7,942,724 7,942,724 7,942,724 7,942,724 7,942,724 7,942,724                
Amortized Cost [7],[32] $ 8,000,000.0                            
Fair Value [4],[7],[32] $ (8,200,000)                            
Investment, Identifier [Axis]: Lipari Foods LLC, Common Stock, Food & Staples Retailing                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[32]               7,936,123 7,936,123 7,936,123 7,936,123 7,936,123 7,936,123 7,936,123  
Amortized Cost [7],[32]               $ 8,000,000.0              
Fair Value [1],[7],[32]               $ (8,000,000.0)              
Investment, Identifier [Axis]: Lipari Foods LLC, Consumer Staples Distribution & Retail 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[15],[20],[41] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base Rate Floor [6],[7],[15],[20],[41] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [7],[13],[15],[20],[41] $ 97,300,000                            
Amortized Cost [7],[15],[20],[41] 96,000,000.0                            
Fair Value [4],[7],[15],[20],[41] $ (97,300,000)                            
Investment, Identifier [Axis]: Lipari Foods LLC, Consumer Staples Distribution & Retail 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base Rate Floor [6],[19] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[19] $ 26,000,000.0                            
Amortized Cost [19] 26,000,000.0                            
Fair Value [4],[19] $ (26,000,000.0)                            
Investment, Identifier [Axis]: Lipari Foods LLC, Food & Staples Retailing 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11],[12],[22]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base Rate Floor [11],[12],[22]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [11],[12],[14],[22]               $ 96,000,000.0              
Amortized Cost [11],[12],[22]               94,600,000              
Fair Value [1],[11],[12],[22]               $ (94,900,000)              
Investment, Identifier [Axis]: Lipari Foods LLC, Food & Staples Retailing 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[18]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base Rate Floor [18]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [14],[18]               $ 27,300,000              
Amortized Cost [18]               27,300,000              
Fair Value [1],[18]               $ (27,000,000.0)              
Investment, Identifier [Axis]: Lloyd's Register Quality Assurance Ltd, Consumer Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Rate, PIK 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Rate, Max PIK 6.30% 6.30% 6.30% 6.30% 6.30% 6.30% 6.30% 6.30% 6.30% 6.30% 6.30% 6.30% 6.30% 6.30%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | €       € 44.3             € 44.3        
Amortized Cost $ 48,800,000             $ 48,800,000              
Fair Value $ (47,100,000)             $ (45,900,000)              
Investment, Identifier [Axis]: Lloyd's Register Quality Assurance Ltd, Consumer Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[7],[33] 5.75% [6],[7],[33] 5.75% [6],[7],[33] 5.75% [6],[7],[33] 5.75% [6],[7],[33] 5.75% [6],[7],[33] 5.75% [6],[7],[33] 5.75% [8],[11],[28] 5.75% [8],[11],[28] 5.75% [8],[11],[28] 5.75% [8],[11],[28] 5.75% [8],[11],[28] 5.75% [8],[11],[28] 5.75% [8],[11],[28]  
Rate, PIK 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [8],[11],[28] 0.00% [8],[11],[28] 0.00% [8],[11],[28] 0.00% [8],[11],[28] 0.00% [8],[11],[28] 0.00% [8],[11],[28] 0.00% [8],[11],[28]  
Rate, Max PIK 2.90% [6],[7],[33] 2.90% [6],[7],[33] 2.90% [6],[7],[33] 2.90% [6],[7],[33] 2.90% [6],[7],[33] 2.90% [6],[7],[33] 2.90% [6],[7],[33] 2.90% [8],[11],[28] 2.90% [8],[11],[28] 2.90% [8],[11],[28] 2.90% [8],[11],[28] 2.90% [8],[11],[28] 2.90% [8],[11],[28] 2.90% [8],[11],[28]  
Base Rate Floor 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28]  
Principal amount | £         £ 5.7 [7],[13],[33]             £ 5.7 [11],[14],[28]      
Amortized Cost $ 7,400,000 [7],[33]             $ 7,400,000 [11],[28]              
Fair Value $ (6,900,000) [4],[7],[33]             $ (6,700,000) [1],[11],[28]              
Investment, Identifier [Axis]: Lloyd's Register Quality Assurance Ltd, Consumer Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[19],[33] 5.75% [6],[19],[33] 5.75% [6],[19],[33] 5.75% [6],[19],[33] 5.75% [6],[19],[33] 5.75% [6],[19],[33] 5.75% [6],[19],[33] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Rate, PIK 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 2.90% 2.90% 2.90% 2.90% 2.90% 2.90% 2.90%  
Rate, Max PIK 2.90% [6],[19],[33] 2.90% [6],[19],[33] 2.90% [6],[19],[33] 2.90% [6],[19],[33] 2.90% [6],[19],[33] 2.90% [6],[19],[33] 2.90% [6],[19],[33] 0.00% [8],[18],[28] 0.00% [8],[18],[28] 0.00% [8],[18],[28] 0.00% [8],[18],[28] 0.00% [8],[18],[28] 0.00% [8],[18],[28] 0.00% [8],[18],[28]  
Base Rate Floor 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [6],[19],[33] 0.00% [18],[28] 0.00% [18],[28] 0.00% [18],[28] 0.00% [18],[28] 0.00% [18],[28] 0.00% [18],[28] 0.00% [18],[28]  
Principal amount | £         £ 9.3 [13],[19],[33]             £ 9.3 [14],[18],[28]      
Amortized Cost $ 12,600,000 [19],[33]             $ 12,600,000 [18],[28]              
Fair Value $ (12,400,000) [4],[19],[33]             $ (12,300,000) [1],[18],[28]              
Investment, Identifier [Axis]: Luxembourg Life Fund - Absolute Return Fund I, 1L Term Loan, Insurance | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%  
Base Rate Floor 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50%  
Principal amount $ 21,100,000             $ 21,300,000              
Amortized Cost 21,100,000             21,300,000              
Fair Value $ (21,200,000)             $ (21,300,000)              
Investment, Identifier [Axis]: Luxembourg Life Fund - Absolute Return Fund II, Structured Mezzanine, Insurance                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [11],[28]               7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%  
Base Rate Floor [11],[28]               0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount [11],[14],[28]               $ 24,900,000              
Amortized Cost [11],[28]               24,900,000              
Fair Value [1],[11],[28]               $ (24,600,000)              
Investment, Identifier [Axis]: Luxembourg Life Fund - Absolute Return Fund II, Structured Mezzanine, Insurance | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%                
Base Rate Floor 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount $ 24,800,000                            
Amortized Cost 24,600,000                            
Fair Value $ (24,700,000)                            
Investment, Identifier [Axis]: Luxembourg Life Fund - Absolute Return Fund III, Term Loan, Insurance | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 9.25% 9.25% 9.25% 9.25% 9.25% 9.25% 9.25% 9.25% 9.25% 9.25% 9.25% 9.25% 9.25% 9.25%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount $ 55,800,000             $ 56,200,000              
Amortized Cost 55,400,000             55,800,000              
Fair Value $ (56,800,000)             $ (57,000,000.0)              
Investment, Identifier [Axis]: Luxembourg Life Fund - Long Term Growth Fund, Term Loan, Insurance | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate               9.25% 9.25% 9.25% 9.25% 9.25% 9.25% 9.25%  
Base Rate Floor               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount               $ 67,400,000              
Amortized Cost               67,400,000              
Fair Value               $ (68,400,000)              
Investment, Identifier [Axis]: MB Precision Holdings LLC, Class A - 2 Units, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [27],[52],[57]               8,081,288 8,081,288 8,081,288 8,081,288 8,081,288 8,081,288 8,081,288  
Amortized Cost [27],[52],[57]               $ 500,000              
Fair Value [1],[27],[52],[57]               $ 0              
Investment, Identifier [Axis]: MB2 Dental Solutions LLC, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[9],[10],[11],[23],[42]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base Rate Floor [9],[10],[11],[23],[42]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [9],[10],[11],[14],[23],[42]               $ 268,000,000.0              
Amortized Cost [9],[10],[11],[23],[42]               259,200,000              
Fair Value [1],[9],[10],[11],[23],[42]               $ (263,600,000)              
Investment, Identifier [Axis]: MB2 Dental Solutions LLC, Health Care Equipment & Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 11,900,000             $ 11,900,000              
Amortized Cost 11,800,000             11,800,000              
Fair Value $ (11,700,000)             $ (11,700,000)              
Investment, Identifier [Axis]: MB2 Dental Solutions LLC, Health Care Equipment & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base Rate Floor [6],[7] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [7],[13] $ 55,800,000                            
Amortized Cost [7] 55,100,000                            
Fair Value [4],[7] $ (54,800,000)                            
Investment, Identifier [Axis]: MB2 Dental Solutions LLC, Health Care Equipment & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[16],[17],[21],[41] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base Rate Floor [6],[7],[16],[17],[21],[41] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [7],[13],[16],[17],[21],[41] $ 139,600,000                            
Amortized Cost [7],[16],[17],[21],[41] 131,900,000                            
Fair Value [4],[7],[16],[17],[21],[41] $ (137,200,000)                            
Investment, Identifier [Axis]: MB2 Dental Solutions LLC, Health Care Equipment & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base Rate Floor [6],[7] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [7],[13] $ 71,900,000                            
Amortized Cost [7] 71,900,000                            
Fair Value [4],[7] $ (70,700,000)                            
Investment, Identifier [Axis]: Magna Legal Services LLC, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[7],[41] 6.50% [6],[7],[41] 6.50% [6],[7],[41] 6.50% [6],[7],[41] 6.50% [6],[7],[41] 6.50% [6],[7],[41] 6.50% [6],[7],[41] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11]  
Base Rate Floor 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 23,000,000.0 [7],[13],[41]             $ 18,500,000 [11],[14]              
Amortized Cost 22,800,000 [7],[41]             18,200,000 [11]              
Fair Value $ (22,900,000) [4],[7],[41]             $ (18,200,000) [1],[11]              
Investment, Identifier [Axis]: Magna Legal Services LLC, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 2,200,000 [13],[19]             $ 2,200,000 [14],[18]              
Amortized Cost 2,200,000 [19]             2,200,000 [18]              
Fair Value $ (2,100,000) [4],[19]             $ (2,100,000) [1],[18]              
Investment, Identifier [Axis]: Magna Legal Services LLC, Commercial & Professional Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 600,000 [13],[19]             $ 5,200,000 [14],[18]              
Amortized Cost 600,000 [19]             5,200,000 [18]              
Fair Value $ (600,000) [4],[19]             $ (5,100,000) [1],[18]              
Investment, Identifier [Axis]: Magna Legal Services LLC, Common Stock, Commercial & Professional Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 4,938,192 [32],[47] 4,938,192 [32],[47] 4,938,192 [32],[47] 4,938,192 [32],[47] 4,938,192 [32],[47] 4,938,192 [32],[47] 4,938,192 [32],[47] 4,938,192 [27],[48] 4,938,192 [27],[48] 4,938,192 [27],[48] 4,938,192 [27],[48] 4,938,192 [27],[48] 4,938,192 [27],[48] 4,938,192 [27],[48]  
Amortized Cost $ 4,900,000 [32],[47]             $ 4,900,000 [27],[48]              
Fair Value $ (5,200,000) [4],[32],[47]             $ (4,900,000) [1],[27],[48]              
Investment, Identifier [Axis]: Matchesfashion Ltd, Consumer Durables & Apparel                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 4.63% [6],[7],[29],[32],[33] 4.63% [6],[7],[29],[32],[33] 4.63% [6],[7],[29],[32],[33] 4.63% [6],[7],[29],[32],[33] 4.63% [6],[7],[29],[32],[33] 4.63% [6],[7],[29],[32],[33] 4.63% [6],[7],[29],[32],[33] 4.63% [8],[11],[24],[27],[28] 4.63% [8],[11],[24],[27],[28] 4.63% [8],[11],[24],[27],[28] 4.63% [8],[11],[24],[27],[28] 4.63% [8],[11],[24],[27],[28] 4.63% [8],[11],[24],[27],[28] 4.63% [8],[11],[24],[27],[28]  
Rate, PIK 3.00% [6],[7],[29],[32],[33] 3.00% [6],[7],[29],[32],[33] 3.00% [6],[7],[29],[32],[33] 3.00% [6],[7],[29],[32],[33] 3.00% [6],[7],[29],[32],[33] 3.00% [6],[7],[29],[32],[33] 3.00% [6],[7],[29],[32],[33] 3.00% [8],[11],[24],[27],[28] 3.00% [8],[11],[24],[27],[28] 3.00% [8],[11],[24],[27],[28] 3.00% [8],[11],[24],[27],[28] 3.00% [8],[11],[24],[27],[28] 3.00% [8],[11],[24],[27],[28] 3.00% [8],[11],[24],[27],[28]  
Rate, Max PIK 3.00% [6],[7],[29],[32],[33] 3.00% [6],[7],[29],[32],[33] 3.00% [6],[7],[29],[32],[33] 3.00% [6],[7],[29],[32],[33] 3.00% [6],[7],[29],[32],[33] 3.00% [6],[7],[29],[32],[33] 3.00% [6],[7],[29],[32],[33] 3.00% [8],[11],[24],[27],[28] 3.00% [8],[11],[24],[27],[28] 3.00% [8],[11],[24],[27],[28] 3.00% [8],[11],[24],[27],[28] 3.00% [8],[11],[24],[27],[28] 3.00% [8],[11],[24],[27],[28] 3.00% [8],[11],[24],[27],[28]  
Base Rate Floor 0.00% [6],[7],[29],[32],[33] 0.00% [6],[7],[29],[32],[33] 0.00% [6],[7],[29],[32],[33] 0.00% [6],[7],[29],[32],[33] 0.00% [6],[7],[29],[32],[33] 0.00% [6],[7],[29],[32],[33] 0.00% [6],[7],[29],[32],[33] 0.00% [11],[24],[27],[28] 0.00% [11],[24],[27],[28] 0.00% [11],[24],[27],[28] 0.00% [11],[24],[27],[28] 0.00% [11],[24],[27],[28] 0.00% [11],[24],[27],[28] 0.00% [11],[24],[27],[28]  
Principal amount $ 13,300,000 [7],[13],[29],[32],[33]             $ 13,300,000 [11],[14],[24],[27],[28]              
Amortized Cost 12,200,000 [7],[29],[32],[33]             12,200,000 [11],[24],[27],[28]              
Fair Value $ (2,800,000) [4],[7],[29],[32],[33]             $ (4,800,000) [1],[11],[24],[27],[28]              
Investment, Identifier [Axis]: Maverick Natural Resources LLC, Common Stock, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [51],[58] 259,211 259,211 259,211 259,211 259,211 259,211 259,211 259,211 259,211 259,211 259,211 259,211 259,211 259,211  
Amortized Cost [51],[58] $ 84,500,000             $ 84,600,000              
Fair Value [51],[58] $ (143,600,000) [4]             $ (160,900,000) [1]              
Investment, Identifier [Axis]: Med-Metrix, Common Stock, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 29,403 [32],[47] 29,403 [32],[47] 29,403 [32],[47] 29,403 [32],[47] 29,403 [32],[47] 29,403 [32],[47] 29,403 [32],[47] 29,403 [27],[48] 29,403 [27],[48] 29,403 [27],[48] 29,403 [27],[48] 29,403 [27],[48] 29,403 [27],[48] 29,403 [27],[48]  
Amortized Cost $ 1,500,000 [32],[47]             $ 1,500,000 [27],[48]              
Fair Value $ (3,300,000) [4],[32],[47]             $ (2,900,000) [1],[27],[48]              
Investment, Identifier [Axis]: Med-Metrix, Preferred Stock, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 8.00% [6] 8.00% [6] 8.00% [6] 8.00% [6] 8.00% [6] 8.00% [6] 8.00% [6] 8.00% [48] 8.00% [48] 8.00% [48] 8.00% [48] 8.00% [48] 8.00% [48] 8.00% [48]  
Rate, Max PIK 8.00% [6] 8.00% [6] 8.00% [6] 8.00% [6] 8.00% [6] 8.00% [6] 8.00% [6] 8.00% [48] 8.00% [48] 8.00% [48] 8.00% [48] 8.00% [48] 8.00% [48] 8.00% [48]  
Number of Shares | shares 29,403 [47] 29,403 [47] 29,403 [47] 29,403 [47] 29,403 [47] 29,403 [47] 29,403 [47] 29,403 [48] 29,403 [48] 29,403 [48] 29,403 [48] 29,403 [48] 29,403 [48] 29,403 [48]  
Amortized Cost $ 1,500,000 [47]             $ 1,500,000 [48]              
Fair Value $ (1,500,000) [4],[47]             $ (1,500,000) [1],[48]              
Investment, Identifier [Axis]: Med-Metrix, Software & Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 11,800,000             $ 11,900,000              
Amortized Cost 11,800,000             11,900,000              
Fair Value $ (12,000,000.0)             $ (12,000,000.0)              
Investment, Identifier [Axis]: Med-Metrix, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[7],[15],[21],[41] 6.00% [6],[7],[15],[21],[41] 6.00% [6],[7],[15],[21],[41] 6.00% [6],[7],[15],[21],[41] 6.00% [6],[7],[15],[21],[41] 6.00% [6],[7],[15],[21],[41] 6.00% [6],[7],[15],[21],[41] 6.00% [8],[11],[12],[23] 6.00% [8],[11],[12],[23] 6.00% [8],[11],[12],[23] 6.00% [8],[11],[12],[23] 6.00% [8],[11],[12],[23] 6.00% [8],[11],[12],[23] 6.00% [8],[11],[12],[23]  
Base Rate Floor 1.00% [6],[7],[15],[21],[41] 1.00% [6],[7],[15],[21],[41] 1.00% [6],[7],[15],[21],[41] 1.00% [6],[7],[15],[21],[41] 1.00% [6],[7],[15],[21],[41] 1.00% [6],[7],[15],[21],[41] 1.00% [6],[7],[15],[21],[41] 1.00% [11],[12],[23] 1.00% [11],[12],[23] 1.00% [11],[12],[23] 1.00% [11],[12],[23] 1.00% [11],[12],[23] 1.00% [11],[12],[23] 1.00% [11],[12],[23]  
Principal amount $ 56,000,000.0 [7],[13],[15],[21],[41]             $ 56,100,000 [11],[12],[14],[23]              
Amortized Cost 55,600,000 [7],[15],[21],[41]             56,100,000 [11],[12],[23]              
Fair Value $ (56,500,000) [4],[7],[15],[21],[41]             $ (56,600,000) [1],[11],[12],[23]              
Investment, Identifier [Axis]: Med-Metrix, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 25,000,000.0 [13],[19]             $ 25,000,000.0 [14],[18]              
Amortized Cost 25,000,000.0 [19]             25,000,000.0 [18]              
Fair Value $ (25,300,000) [4],[19]             $ (25,300,000) [1],[18]              
Investment, Identifier [Axis]: Med-Metrix, Software & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 7,800,000 [13],[19]             $ 7,800,000 [14],[18]              
Amortized Cost 7,800,000 [19]             7,800,000 [18]              
Fair Value $ (7,800,000) [4],[19]             $ (7,800,000) [1],[18]              
Investment, Identifier [Axis]: Medallia Inc, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 3.25% [6],[7],[41] 3.25% [6],[7],[41] 3.25% [6],[7],[41] 3.25% [6],[7],[41] 3.25% [6],[7],[41] 3.25% [6],[7],[41] 3.25% [6],[7],[41] 3.25% [8],[11] 3.25% [8],[11] 3.25% [8],[11] 3.25% [8],[11] 3.25% [8],[11] 3.25% [8],[11] 3.25% [8],[11]  
Rate, PIK 3.30% [6],[7],[41] 3.30% [6],[7],[41] 3.30% [6],[7],[41] 3.30% [6],[7],[41] 3.30% [6],[7],[41] 3.30% [6],[7],[41] 3.30% [6],[7],[41] 3.30% [8],[11] 3.30% [8],[11] 3.30% [8],[11] 3.30% [8],[11] 3.30% [8],[11] 3.30% [8],[11] 3.30% [8],[11]  
Rate, Max PIK 3.30% [6],[7],[41] 3.30% [6],[7],[41] 3.30% [6],[7],[41] 3.30% [6],[7],[41] 3.30% [6],[7],[41] 3.30% [6],[7],[41] 3.30% [6],[7],[41] 3.30% [8],[11] 3.30% [8],[11] 3.30% [8],[11] 3.30% [8],[11] 3.30% [8],[11] 3.30% [8],[11] 3.30% [8],[11]  
Base Rate Floor 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 210,700,000 [7],[13],[41]             $ 207,800,000 [11],[14]              
Amortized Cost 208,700,000 [7],[41]             205,800,000 [11]              
Fair Value $ (204,800,000) [4],[7],[41]             $ (203,000,000.0) [1],[11]              
Investment, Identifier [Axis]: Miami Beach Medical Group LLC, Common Stock, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[32]               5,000,000 5,000,000 5,000,000 5,000,000 5,000,000 5,000,000 5,000,000  
Amortized Cost [7],[32]               $ 4,800,000              
Fair Value [1],[7],[32]               $ 0              
Investment, Identifier [Axis]: Miami Beach Medical Group LLC, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11],[42]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Rate, PIK [8],[11],[42]               1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50%  
Rate, Max PIK [8],[11],[42]               1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50%  
Base Rate Floor [11],[42]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [11],[14],[42]               $ 164,400,000              
Amortized Cost [11],[42]               157,100,000              
Fair Value [1],[11],[42]               (139,800,000)              
Investment, Identifier [Axis]: Miami Beach Medical Group LLC, Health Care Equipment & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[41] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Rate, PIK [6],[7],[41] 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50%                
Rate, Max PIK [6],[7],[41] 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50%                
Base Rate Floor [6],[7],[41] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [7],[13],[41] $ 132,000,000.0                            
Amortized Cost [7],[41] 126,600,000                            
Fair Value [4],[7],[41] (116,200,000)                            
Investment, Identifier [Axis]: Miami Beach Medical Group LLC, Health Care Equipment & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [7],[13],[32] 5,000,000.0                            
Amortized Cost [7],[32] 3,600,000                            
Fair Value [4],[7],[32] $ (2,700,000)                            
Investment, Identifier [Axis]: Micronics Filtration Holdings Inc, Common Stock, Equity/Other                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               0             0
Investment, Identifier [Axis]: Micronics Filtration Holdings Inc, Senior Secured Loans—First Lien                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ 0             (51,000,000.0)
Investment, Identifier [Axis]: Misys Ltd, Preferred Stock, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 10.25% [6],[7],[33] 10.25% [6],[7],[33] 10.25% [6],[7],[33] 10.25% [6],[7],[33] 10.25% [6],[7],[33] 10.25% [6],[7],[33] 10.25% [6],[7],[33] 10.25% [11],[28] 10.25% [11],[28] 10.25% [11],[28] 10.25% [11],[28] 10.25% [11],[28] 10.25% [11],[28] 10.25% [11],[28]  
Rate, Max PIK 10.25% [6],[7],[33] 10.25% [6],[7],[33] 10.25% [6],[7],[33] 10.25% [6],[7],[33] 10.25% [6],[7],[33] 10.25% [6],[7],[33] 10.25% [6],[7],[33] 10.25% [11],[28] 10.25% [11],[28] 10.25% [11],[28] 10.25% [11],[28] 10.25% [11],[28] 10.25% [11],[28] 10.25% [11],[28]  
Base Rate Floor [6],[7],[33] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Number of Shares | shares 67,825,135 [7],[33] 67,825,135 [7],[33] 67,825,135 [7],[33] 67,825,135 [7],[33] 67,825,135 [7],[33] 67,825,135 [7],[33] 67,825,135 [7],[33] 65,200,765 [11],[28] 65,200,765 [11],[28] 65,200,765 [11],[28] 65,200,765 [11],[28] 65,200,765 [11],[28] 65,200,765 [11],[28] 65,200,765 [11],[28]  
Amortized Cost $ 63,800,000 [7],[33]             $ 61,100,000 [11],[28]              
Fair Value $ (64,500,000) [4],[7],[33]             $ (61,100,000) [1],[11],[28]              
Investment, Identifier [Axis]: Misys Ltd, Preferred Stock, Software & Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 1025.00% 1025.00% 1025.00% 1025.00% 1025.00% 1025.00% 1025.00% 10.25% 10.25% 10.25% 10.25% 10.25% 10.25% 10.25%  
Rate, Max PIK 1025.00% 1025.00% 1025.00% 1025.00% 1025.00% 1025.00% 1025.00% 10.25% 10.25% 10.25% 10.25% 10.25% 10.25% 10.25%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Number of Shares | shares 26,221,656 26,221,656 26,221,656 26,221,656 26,221,656 26,221,656 26,221,656 25,265,621 25,265,621 25,265,621 25,265,621 25,265,621 25,265,621 25,265,621  
Amortized Cost $ 25,700,000             $ 24,800,000              
Fair Value $ (22,900,000)             $ (21,100,000)              
Investment, Identifier [Axis]: Misys Ltd, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.25% [6],[7],[33],[39] 7.25% [6],[7],[33],[39] 7.25% [6],[7],[33],[39] 7.25% [6],[7],[33],[39] 7.25% [6],[7],[33],[39] 7.25% [6],[7],[33],[39] 7.25% [6],[7],[33],[39] 7.25% [8],[11],[28],[40] 7.25% [8],[11],[28],[40] 7.25% [8],[11],[28],[40] 7.25% [8],[11],[28],[40] 7.25% [8],[11],[28],[40] 7.25% [8],[11],[28],[40] 7.25% [8],[11],[28],[40]  
Base Rate Floor 1.00% [6],[7],[33],[39] 1.00% [6],[7],[33],[39] 1.00% [6],[7],[33],[39] 1.00% [6],[7],[33],[39] 1.00% [6],[7],[33],[39] 1.00% [6],[7],[33],[39] 1.00% [6],[7],[33],[39] 1.00% [11],[28],[40] 1.00% [11],[28],[40] 1.00% [11],[28],[40] 1.00% [11],[28],[40] 1.00% [11],[28],[40] 1.00% [11],[28],[40] 1.00% [11],[28],[40]  
Principal amount $ 16,300,000 [7],[13],[33],[39]             $ 16,300,000 [11],[14],[28],[40]              
Amortized Cost 15,700,000 [7],[33],[39]             15,600,000 [11],[28],[40]              
Fair Value $ (13,300,000) [4],[7],[33],[39]             $ (12,300,000) [1],[11],[28],[40]              
Investment, Identifier [Axis]: Misys Ltd, Software & Services 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 2,300,000             $ 2,300,000              
Amortized Cost 2,200,000             2,200,000              
Fair Value $ (2,100,000)             $ (2,000,000.0)              
Investment, Identifier [Axis]: Misys Ltd, Software & Services 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 46,600,000             $ 46,600,000              
Amortized Cost 44,900,000             44,600,000              
Fair Value $ (37,800,000)             $ (35,100,000)              
Investment, Identifier [Axis]: Monitronics International Inc, Commercial & Professional Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base Rate Floor 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50%  
Principal amount $ 35,500,000             $ 35,500,000              
Amortized Cost 33,900,000             33,700,000              
Fair Value $ (33,800,000)             $ (33,700,000)              
Investment, Identifier [Axis]: Monitronics International Inc, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.50% [6],[7],[20],[29],[32],[39] 7.50% [6],[7],[20],[29],[32],[39] 7.50% [6],[7],[20],[29],[32],[39] 7.50% [6],[7],[20],[29],[32],[39] 7.50% [6],[7],[20],[29],[32],[39] 7.50% [6],[7],[20],[29],[32],[39] 7.50% [6],[7],[20],[29],[32],[39] 7.50% [8],[11],[22],[40] 7.50% [8],[11],[22],[40] 7.50% [8],[11],[22],[40] 7.50% [8],[11],[22],[40] 7.50% [8],[11],[22],[40] 7.50% [8],[11],[22],[40] 7.50% [8],[11],[22],[40]  
Base Rate Floor 1.30% [6],[7],[20],[29],[32],[39] 1.30% [6],[7],[20],[29],[32],[39] 1.30% [6],[7],[20],[29],[32],[39] 1.30% [6],[7],[20],[29],[32],[39] 1.30% [6],[7],[20],[29],[32],[39] 1.30% [6],[7],[20],[29],[32],[39] 1.30% [6],[7],[20],[29],[32],[39] 1.30% [11],[22],[40] 1.30% [11],[22],[40] 1.30% [11],[22],[40] 1.30% [11],[22],[40] 1.30% [11],[22],[40] 1.30% [11],[22],[40] 1.30% [11],[22],[40]  
Principal amount $ 18,600,000 [7],[13],[20],[29],[32],[39]             $ 18,600,000 [11],[14],[22],[40]              
Amortized Cost 17,700,000 [7],[20],[29],[32],[39]             17,700,000 [11],[22],[40]              
Fair Value $ (7,700,000) [4],[7],[20],[29],[32],[39]             $ (12,500,000) [1],[11],[22],[40]              
Investment, Identifier [Axis]: Monitronics International Inc, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [8],[11] 6.00% [8],[11] 6.00% [8],[11] 6.00% [8],[11] 6.00% [8],[11] 6.00% [8],[11] 6.00% [8],[11]  
Base Rate Floor 1.50% [6],[7] 1.50% [6],[7] 1.50% [6],[7] 1.50% [6],[7] 1.50% [6],[7] 1.50% [6],[7] 1.50% [6],[7] 1.50% [11] 1.50% [11] 1.50% [11] 1.50% [11] 1.50% [11] 1.50% [11] 1.50% [11]  
Principal amount $ 54,300,000 [7],[13]             $ 46,100,000 [11],[14]              
Amortized Cost 52,700,000 [7]             44,300,000 [11]              
Fair Value $ (50,500,000) [4],[7]             $ (42,300,000) [1],[11]              
Investment, Identifier [Axis]: Monitronics International Inc, Commercial & Professional Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18]  
Base Rate Floor 1.50% [6],[19] 1.50% [6],[19] 1.50% [6],[19] 1.50% [6],[19] 1.50% [6],[19] 1.50% [6],[19] 1.50% [6],[19] 1.50% [18] 1.50% [18] 1.50% [18] 1.50% [18] 1.50% [18] 1.50% [18] 1.50% [18]  
Principal amount $ 15,700,000 [13],[19]             $ 23,900,000 [14],[18]              
Amortized Cost 15,700,000 [19]             23,900,000 [18]              
Fair Value $ (14,600,000) [4],[19]             $ (21,900,000) [1],[18]              
Investment, Identifier [Axis]: Motion Recruitment Partners LLC, Commercial & Professional Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 24,700,000             $ 24,800,000              
Amortized Cost 24,500,000             24,500,000              
Fair Value $ (24,700,000)             $ (24,600,000)              
Investment, Identifier [Axis]: Motion Recruitment Partners LLC, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[7],[15],[20] 6.50% [6],[7],[15],[20] 6.50% [6],[7],[15],[20] 6.50% [6],[7],[15],[20] 6.50% [6],[7],[15],[20] 6.50% [6],[7],[15],[20] 6.50% [6],[7],[15],[20] 6.50% [8],[11],[12],[22] 6.50% [8],[11],[12],[22] 6.50% [8],[11],[12],[22] 6.50% [8],[11],[12],[22] 6.50% [8],[11],[12],[22] 6.50% [8],[11],[12],[22] 6.50% [8],[11],[12],[22]  
Base Rate Floor 1.00% [6],[7],[15],[20] 1.00% [6],[7],[15],[20] 1.00% [6],[7],[15],[20] 1.00% [6],[7],[15],[20] 1.00% [6],[7],[15],[20] 1.00% [6],[7],[15],[20] 1.00% [6],[7],[15],[20] 1.00% [11],[12],[22] 1.00% [11],[12],[22] 1.00% [11],[12],[22] 1.00% [11],[12],[22] 1.00% [11],[12],[22] 1.00% [11],[12],[22] 1.00% [11],[12],[22]  
Principal amount $ 63,800,000 [7],[13],[15],[20]             $ 64,000,000.0 [11],[12],[14],[22]              
Amortized Cost 63,800,000 [7],[15],[20]             64,000,000.0 [11],[12],[22]              
Fair Value $ (63,700,000) [4],[7],[15],[20]             $ (63,600,000) [1],[11],[12],[22]              
Investment, Identifier [Axis]: Motion Recruitment Partners LLC, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[7],[21] 6.50% [6],[7],[21] 6.50% [6],[7],[21] 6.50% [6],[7],[21] 6.50% [6],[7],[21] 6.50% [6],[7],[21] 6.50% [6],[7],[21] 6.50% [8],[11],[23],[42] 6.50% [8],[11],[23],[42] 6.50% [8],[11],[23],[42] 6.50% [8],[11],[23],[42] 6.50% [8],[11],[23],[42] 6.50% [8],[11],[23],[42] 6.50% [8],[11],[23],[42]  
Base Rate Floor 1.00% [6],[7],[21] 1.00% [6],[7],[21] 1.00% [6],[7],[21] 1.00% [6],[7],[21] 1.00% [6],[7],[21] 1.00% [6],[7],[21] 1.00% [6],[7],[21] 1.00% [11],[23],[42] 1.00% [11],[23],[42] 1.00% [11],[23],[42] 1.00% [11],[23],[42] 1.00% [11],[23],[42] 1.00% [11],[23],[42] 1.00% [11],[23],[42]  
Principal amount $ 54,500,000 [7],[13],[21]             $ 59,400,000 [11],[14],[23],[42]              
Amortized Cost 51,300,000 [7],[21]             55,800,000 [11],[23],[42]              
Fair Value $ (54,400,000) [4],[7],[21]             $ (59,000,000.0) [1],[11],[23],[42]              
Investment, Identifier [Axis]: Motion Recruitment Partners LLC, Commercial & Professional Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 4,700,000 [7],[13]             $ 59,600,000 [14],[18]              
Amortized Cost 4,500,000 [7]             59,600,000 [18]              
Fair Value $ (4,700,000) [4],[7]             (59,200,000) [1],[18]              
Investment, Identifier [Axis]: Motion Recruitment Partners LLC, Commercial & Professional Services 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base Rate Floor [6],[19] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[19] $ 59,600,000                            
Amortized Cost [19] 59,600,000                            
Fair Value [4],[19] (59,500,000)                            
Investment, Identifier [Axis]: My Community Homes PropCo 2, Private Equity                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (80,500,000)             $ (79,000,000.0)              
Investment, Identifier [Axis]: My Community Homes PropCo 2, Private Equity, Equity Real Estate Investment Trusts (REITs)                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[13],[32],[33],[34] 81,818,354 81,818,354 81,818,354 81,818,354 81,818,354 81,818,354 81,818,354                
Amortized Cost [7],[32],[33],[34] $ 81,800,000                            
Fair Value [4],[7],[32],[33],[34] $ (80,500,000)                            
Investment, Identifier [Axis]: My Community Homes PropCo 2, Private Equity, Equity Real Estate Investment Trusts (REITs) | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 33,689,910 33,689,910 33,689,910 33,689,910 33,689,910 33,689,910 33,689,910                
Amortized Cost $ 33,700,000                            
Fair Value $ (33,200,000)                            
Investment, Identifier [Axis]: My Community Homes PropCo 2, Private Equity, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[14],[32],[33],[34]               84,291,667 84,291,667 84,291,667 84,291,667 84,291,667 84,291,667 84,291,667  
Amortized Cost [7],[32],[33],[34]               $ 84,300,000              
Fair Value [1],[7],[32],[33],[34]               $ (79,000,000.0)              
Investment, Identifier [Axis]: My Community Homes PropCo 2, Private Equity, Real Estate | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate               17.80% 17.80% 17.80% 17.80% 17.80% 17.80% 17.80%  
Number of Shares | shares               34,708,333 34,708,333 34,708,333 34,708,333 34,708,333 34,708,333 34,708,333  
Amortized Cost               $ 34,700,000              
Fair Value               (32,500,000)              
Investment, Identifier [Axis]: My Community Homes SFR PropCo 2, Private Equity                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ (79,000,000.0)             (33,000,000.0)
Investment, Identifier [Axis]: NBG Home, Common Stock, Consumer Durables & Apparel                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[32] 1,903 1,903 1,903 1,903 1,903 1,903 1,903 1,903 1,903 1,903 1,903 1,903 1,903 1,903  
Amortized Cost [7],[32] $ 2,400,000             $ 2,400,000              
Fair Value [7],[32] $ 0 [4]             $ 0 [1]              
Investment, Identifier [Axis]: NBG Home, Consumer Durables & Apparel 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11],[24],[27]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Rate, PIK [6],[7] 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%                
Rate, Max PIK [6],[7] 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%                
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [11],[24],[27] 1.00% [11],[24],[27] 1.00% [11],[24],[27] 1.00% [11],[24],[27] 1.00% [11],[24],[27] 1.00% [11],[24],[27] 1.00% [11],[24],[27]  
Principal amount $ 26,100,000 [7],[13]             $ 75,900,000 [11],[14],[24],[27]              
Amortized Cost 26,100,000 [7]             69,900,000 [11],[24],[27]              
Fair Value $ (26,100,000) [4],[7]             $ (21,200,000) [1],[11],[24],[27]              
Investment, Identifier [Axis]: NBG Home, Consumer Durables & Apparel 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[29],[32] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Rate, PIK [8],[11],[24],[27]               12.75% 12.75% 12.75% 12.75% 12.75% 12.75% 12.75%  
Rate, Max PIK [8],[11],[24],[27]               12.75% 12.75% 12.75% 12.75% 12.75% 12.75% 12.75%  
Base Rate Floor 1.00% [6],[7],[29],[32] 1.00% [6],[7],[29],[32] 1.00% [6],[7],[29],[32] 1.00% [6],[7],[29],[32] 1.00% [6],[7],[29],[32] 1.00% [6],[7],[29],[32] 1.00% [6],[7],[29],[32] 1.00% [11],[24],[27] 1.00% [11],[24],[27] 1.00% [11],[24],[27] 1.00% [11],[24],[27] 1.00% [11],[24],[27] 1.00% [11],[24],[27] 1.00% [11],[24],[27]  
Principal amount $ 63,200,000 [7],[13],[29],[32]             $ 35,800,000 [11],[14],[24],[27]              
Amortized Cost 57,200,000 [7],[29],[32]             28,200,000 [11],[24],[27]              
Fair Value $ (23,400,000) [4],[7],[29],[32]             0 [1],[11],[24],[27]              
Investment, Identifier [Axis]: NBG Home, Consumer Durables & Apparel 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK [6],[19] 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%                
Rate, Max PIK [6],[19] 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%                
Base Rate Floor [6],[19] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[19] $ 1,000,000.0                            
Amortized Cost [19] 1,000,000.0                            
Fair Value [4],[19] $ (1,000,000.0)                            
Investment, Identifier [Axis]: NBG Home, Consumer Durables & Apparel 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK [6],[7],[29],[32] 12.75% 12.75% 12.75% 12.75% 12.75% 12.75% 12.75%                
Rate, Max PIK [6],[7],[29],[32] 12.75% 12.75% 12.75% 12.75% 12.75% 12.75% 12.75%                
Base Rate Floor [6],[7],[29],[32] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [7],[13],[29],[32] $ 37,400,000                            
Amortized Cost [7],[29],[32] 28,200,000                            
Fair Value [4],[7],[29],[32] 0                            
Investment, Identifier [Axis]: NCI Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value (29,200,000)             (28,100,000)             0
Investment, Identifier [Axis]: NCI Inc, Class A-1 Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ 0             $ 0 [5]             0 [5]
Investment, Identifier [Axis]: NCI Inc, Class A-1 Common Stock, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 42,923 [7],[32],[34] 42,923 [7],[32],[34] 42,923 [7],[32],[34] 42,923 [7],[32],[34] 42,923 [7],[32],[34] 42,923 [7],[32],[34] 42,923 [7],[32],[34] 42,923 [11],[27],[35] 42,923 [11],[27],[35] 42,923 [11],[27],[35] 42,923 [11],[27],[35] 42,923 [11],[27],[35] 42,923 [11],[27],[35] 42,923 [11],[27],[35]  
Amortized Cost $ 0 [7],[32],[34]             $ 0 [11],[27],[35]              
Fair Value 0 [4],[7],[32],[34]             0 [1],[11],[27],[35]              
Investment, Identifier [Axis]: NCI Inc, Class B-1 Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ 0             $ 0 [5]             0 [5]
Investment, Identifier [Axis]: NCI Inc, Class B-1 Common Stock, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 30,121 [7],[32],[34] 30,121 [7],[32],[34] 30,121 [7],[32],[34] 30,121 [7],[32],[34] 30,121 [7],[32],[34] 30,121 [7],[32],[34] 30,121 [7],[32],[34] 30,121 [11],[27],[35] 30,121 [11],[27],[35] 30,121 [11],[27],[35] 30,121 [11],[27],[35] 30,121 [11],[27],[35] 30,121 [11],[27],[35] 30,121 [11],[27],[35]  
Amortized Cost $ 0 [7],[32],[34]             $ 0 [11],[27],[35]              
Fair Value 0 [4],[7],[32],[34]             0 [1],[11],[27],[35]              
Investment, Identifier [Axis]: NCI Inc, Class C Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (19,100,000)             $ (20,200,000) [5]             0 [5]
Investment, Identifier [Axis]: NCI Inc, Class C Common Stock, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 49,406 [7],[32],[34] 49,406 [7],[32],[34] 49,406 [7],[32],[34] 49,406 [7],[32],[34] 49,406 [7],[32],[34] 49,406 [7],[32],[34] 49,406 [7],[32],[34] 49,406 [11],[27],[35] 49,406 [11],[27],[35] 49,406 [11],[27],[35] 49,406 [11],[27],[35] 49,406 [11],[27],[35] 49,406 [11],[27],[35] 49,406 [11],[27],[35]  
Amortized Cost $ 20,200,000 [7],[32],[34]             $ 20,200,000 [11],[27],[35]              
Fair Value (19,100,000) [4],[7],[32],[34]             (20,200,000) [1],[11],[27],[35]              
Investment, Identifier [Axis]: NCI Inc, Class I-1 Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ 0             $ 0 [5]             0 [5]
Investment, Identifier [Axis]: NCI Inc, Class I-1 Common Stock, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 42,923 [7],[32],[34] 42,923 [7],[32],[34] 42,923 [7],[32],[34] 42,923 [7],[32],[34] 42,923 [7],[32],[34] 42,923 [7],[32],[34] 42,923 [7],[32],[34] 42,923 [11],[27],[35] 42,923 [11],[27],[35] 42,923 [11],[27],[35] 42,923 [11],[27],[35] 42,923 [11],[27],[35] 42,923 [11],[27],[35] 42,923 [11],[27],[35]  
Amortized Cost $ 0.0 [7],[32],[34]             $ 0 [11],[27],[35]              
Fair Value $ 0 [4],[7],[32],[34]             $ 0 [1],[11],[27],[35]              
Investment, Identifier [Axis]: NCI Inc, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 7.50% [6],[7],[34] 7.50% [6],[7],[34] 7.50% [6],[7],[34] 7.50% [6],[7],[34] 7.50% [6],[7],[34] 7.50% [6],[7],[34] 7.50% [6],[7],[34] 7.50% [8],[11],[35] 7.50% [8],[11],[35] 7.50% [8],[11],[35] 7.50% [8],[11],[35] 7.50% [8],[11],[35] 7.50% [8],[11],[35] 7.50% [8],[11],[35]  
Rate, Max PIK 7.50% [6],[7],[34] 7.50% [6],[7],[34] 7.50% [6],[7],[34] 7.50% [6],[7],[34] 7.50% [6],[7],[34] 7.50% [6],[7],[34] 7.50% [6],[7],[34] 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%  
Base Rate Floor 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35]  
Principal amount $ 29,200,000 [7],[13],[34]             $ 28,100,000 [11],[14],[35]              
Amortized Cost 29,500,000 [7],[34]             28,700,000 [11],[35]              
Fair Value $ (29,200,000) [4],[7],[34]             $ (28,100,000) [1],[11],[35]              
Investment, Identifier [Axis]: NEP Broadcasting LLC, Media & Entertainment | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount $ 6,800,000             $ 6,800,000              
Amortized Cost 6,800,000             6,700,000              
Fair Value $ (5,600,000)             $ (5,100,000)              
Investment, Identifier [Axis]: NPD Group Inc/The, Consumer Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base Rate Floor [11]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [11],[14]               $ 100,000              
Amortized Cost [11]               100,000              
Fair Value [1],[11]               $ (100,000)              
Investment, Identifier [Axis]: NPD Group Inc/The, Consumer Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11]               3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50%  
Rate, PIK [8],[11]               2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80%  
Rate, Max PIK [8],[11]               2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80%  
Base Rate Floor [11]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [11],[14]               $ 19,200,000              
Amortized Cost [11]               19,200,000              
Fair Value [1],[11]               $ (19,200,000)              
Investment, Identifier [Axis]: NPD Group Inc/The, Consumer Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[18]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base Rate Floor [18]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [14],[18]               $ 900,000              
Amortized Cost [18]               900,000              
Fair Value [1],[18]               $ (900,000)              
Investment, Identifier [Axis]: Net Documents, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Principal amount $ 33,000,000.0 [7],[13]             $ 33,000,000.0 [11],[14]              
Amortized Cost 32,800,000 [7]             32,800,000 [11]              
Fair Value $ (32,000,000.0) [4],[7]             $ (32,000,000.0) [1],[11]              
Investment, Identifier [Axis]: Net Documents, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 300,000 [7],[13]             $ 3,000,000.0 [14],[18]              
Amortized Cost 300,000 [7]             2,900,000 [18]              
Fair Value $ (300,000) [4],[7]             $ (2,900,000) [1],[18]              
Investment, Identifier [Axis]: Net Documents, Software & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base Rate Floor [6],[19] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[19] $ 2,700,000                            
Amortized Cost [19] 2,700,000                            
Fair Value [4],[19] $ (2,600,000)                            
Investment, Identifier [Axis]: New Era Technology Inc, Software & Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base Rate Floor               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount               $ 34,300,000              
Amortized Cost               33,800,000              
Fair Value               $ (33,700,000)              
Investment, Identifier [Axis]: New Era Technology Inc, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[7],[15],[17],[21] 6.25% [6],[7],[15],[17],[21] 6.25% [6],[7],[15],[17],[21] 6.25% [6],[7],[15],[17],[21] 6.25% [6],[7],[15],[17],[21] 6.25% [6],[7],[15],[17],[21] 6.25% [6],[7],[15],[17],[21] 6.25% [8],[10],[12],[23],[42] 6.25% [8],[10],[12],[23],[42] 6.25% [8],[10],[12],[23],[42] 6.25% [8],[10],[12],[23],[42] 6.25% [8],[10],[12],[23],[42] 6.25% [8],[10],[12],[23],[42] 6.25% [8],[10],[12],[23],[42]  
Base Rate Floor 1.00% [6],[7],[15],[17],[21] 1.00% [6],[7],[15],[17],[21] 1.00% [6],[7],[15],[17],[21] 1.00% [6],[7],[15],[17],[21] 1.00% [6],[7],[15],[17],[21] 1.00% [6],[7],[15],[17],[21] 1.00% [6],[7],[15],[17],[21] 1.00% [10],[12],[23],[42] 1.00% [10],[12],[23],[42] 1.00% [10],[12],[23],[42] 1.00% [10],[12],[23],[42] 1.00% [10],[12],[23],[42] 1.00% [10],[12],[23],[42] 1.00% [10],[12],[23],[42]  
Principal amount $ 34,200,000 [7],[13],[15],[17],[21]             $ 51,100,000 [10],[12],[14],[23],[42]              
Amortized Cost 32,800,000 [7],[15],[17],[21]             49,400,000 [10],[12],[23],[42]              
Fair Value $ (33,700,000) [4],[7],[15],[17],[21]             $ (50,200,000) [1],[10],[12],[23],[42]              
Investment, Identifier [Axis]: New Era Technology Inc, Software & Services 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount $ 9,900,000                            
Amortized Cost 9,900,000                            
Fair Value $ (9,700,000)                            
Investment, Identifier [Axis]: New Era Technology Inc, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Principal amount $ 3,500,000 [7],[13]             $ 2,600,000 [11],[14]              
Amortized Cost 3,500,000 [7]             2,500,000 [11]              
Fair Value $ (3,500,000) [4],[7]             $ (2,500,000) [1],[11]              
Investment, Identifier [Axis]: New Era Technology Inc, Software & Services 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount $ 24,300,000                            
Amortized Cost 23,900,000                            
Fair Value $ (24,000,000.0)                            
Investment, Identifier [Axis]: New Era Technology Inc, Software & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[15],[21] 6.25% [6],[15],[21] 6.25% [6],[15],[21] 6.25% [6],[15],[21] 6.25% [6],[15],[21] 6.25% [6],[15],[21] 6.25% [6],[15],[21] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18]  
Base Rate Floor 1.00% [6],[15],[21] 1.00% [6],[15],[21] 1.00% [6],[15],[21] 1.00% [6],[15],[21] 1.00% [6],[15],[21] 1.00% [6],[15],[21] 1.00% [6],[15],[21] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 16,700,000 [13],[15],[21]             $ 2,100,000 [14],[18]              
Amortized Cost 16,700,000 [15],[21]             2,100,000 [18]              
Fair Value $ (16,500,000) [4],[15],[21]             $ (2,100,000) [1],[18]              
Investment, Identifier [Axis]: New Era Technology Inc, Software & Services 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base Rate Floor [6],[19] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[19] $ 1,200,000                            
Amortized Cost [19] 1,200,000                            
Fair Value [4],[19] $ (1,200,000)                            
Investment, Identifier [Axis]: NewStar Clarendon 2014-1A Class D, Diversified Financials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate [11],[28]               19.30% 19.30% 19.30% 19.30% 19.30% 19.30% 19.30%  
Principal amount [11],[14],[28]               $ 8,300,000              
Amortized Cost [11],[28]               2,500,000              
Fair Value [1],[11],[28]               $ (3,500,000)              
Investment, Identifier [Axis]: NewStar Clarendon 2014-1A Class D, Diversified Financials | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK               5.30% 5.30% 5.30% 5.30% 5.30% 5.30% 5.30%  
Rate, Max PIK               5.30% 5.30% 5.30% 5.30% 5.30% 5.30% 5.30%  
Rate, Stated interest rate               2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80%  
Principal amount               $ 30,000,000.0              
Amortized Cost               9,300,000              
Fair Value               $ (12,700,000)              
Investment, Identifier [Axis]: NewStar Clarendon 2014-1A Class D, Financial Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate [7],[33] 18.30% 18.30% 18.30% 18.30% 18.30% 18.30% 18.30%                
Principal amount [7],[33] $ 8,300,000                            
Amortized Cost [7],[33] 2,500,000                            
Fair Value [7],[33] $ (3,700,000)                            
Investment, Identifier [Axis]: NewStar Clarendon 2014-1A Class D, Financial Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate 16.80% 16.80% 16.80% 16.80% 16.80% 16.80% 16.80%                
Principal amount $ 30,000,000.0                            
Amortized Cost 9,300,000                            
Fair Value $ (13,300,000)                            
Investment, Identifier [Axis]: Nine West Holdings Inc, Common Stock, Consumer Durables & Apparel                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[32] 5,451 [34] 5,451 [34] 5,451 [34] 5,451 [34] 5,451 [34] 5,451 [34] 5,451 [34] 5,451 5,451 5,451 5,451 5,451 5,451 5,451  
Amortized Cost [7],[32] $ 6,400,000 [34]             $ 6,400,000              
Fair Value [7],[32] $ 0 [34]             $ 0 [1]              
Investment, Identifier [Axis]: Novotech Pty Ltd, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% [6],[19],[33] 5.25% [6],[19],[33] 5.25% [6],[19],[33] 5.25% [6],[19],[33] 5.25% [6],[19],[33] 5.25% [6],[19],[33] 5.25% [6],[19],[33] 5.25% [8],[18],[28] 5.25% [8],[18],[28] 5.25% [8],[18],[28] 5.25% [8],[18],[28] 5.25% [8],[18],[28] 5.25% [8],[18],[28] 5.25% [8],[18],[28]  
Base Rate Floor 0.50% [6],[19],[33] 0.50% [6],[19],[33] 0.50% [6],[19],[33] 0.50% [6],[19],[33] 0.50% [6],[19],[33] 0.50% [6],[19],[33] 0.50% [6],[19],[33] 0.50% [18],[28] 0.50% [18],[28] 0.50% [18],[28] 0.50% [18],[28] 0.50% [18],[28] 0.50% [18],[28] 0.50% [18],[28]  
Principal amount $ 5,700,000 [13],[19],[33]             $ 5,700,000 [14],[18],[28]              
Amortized Cost 5,600,000 [19],[33]             5,600,000 [18],[28]              
Fair Value $ (5,500,000) [4],[19],[33]             $ (5,500,000) [1],[18],[28]              
Investment, Identifier [Axis]: Novotech Pty Ltd, Health Care Equipment & Services 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%  
Base Rate Floor 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount $ 24,400,000             $ 24,400,000              
Amortized Cost 24,000,000.0             23,900,000              
Fair Value $ (23,800,000)             $ (23,600,000)              
Investment, Identifier [Axis]: Novotech Pty Ltd, Health Care Equipment & Services 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%  
Base Rate Floor 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount           $ 33.7             $ 33.7    
Amortized Cost $ 24,800,000             $ 24,800,000              
Fair Value $ (21,900,000)             $ (22,100,000)              
Investment, Identifier [Axis]: OEConnection LLC, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.00% [6],[7],[20] 7.00% [6],[7],[20] 7.00% [6],[7],[20] 7.00% [6],[7],[20] 7.00% [6],[7],[20] 7.00% [6],[7],[20] 7.00% [6],[7],[20] 7.00% [8],[11],[22] 7.00% [8],[11],[22] 7.00% [8],[11],[22] 7.00% [8],[11],[22] 7.00% [8],[11],[22] 7.00% [8],[11],[22] 7.00% [8],[11],[22]  
Base Rate Floor 0.50% [6],[7],[20] 0.50% [6],[7],[20] 0.50% [6],[7],[20] 0.50% [6],[7],[20] 0.50% [6],[7],[20] 0.50% [6],[7],[20] 0.50% [6],[7],[20] 0.50% [11],[22] 0.50% [11],[22] 0.50% [11],[22] 0.50% [11],[22] 0.50% [11],[22] 0.50% [11],[22] 0.50% [11],[22]  
Principal amount $ 76,100,000 [7],[13],[20]             $ 76,100,000 [11],[14],[22]              
Amortized Cost 75,700,000 [7],[20]             75,700,000 [11],[22]              
Fair Value $ (73,500,000) [4],[7],[20]             $ (73,600,000) [1],[11],[22]              
Investment, Identifier [Axis]: OEConnection LLC, Software & Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%  
Base Rate Floor 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount $ 50,000,000.0             $ 50,000,000.0              
Amortized Cost 50,000,000.0             50,000,000.0              
Fair Value $ (48,300,000)             $ (48,400,000)              
Investment, Identifier [Axis]: Omnimax International Inc, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 8.50% [6],[7],[15],[16],[17],[20],[41] 8.50% [6],[7],[15],[16],[17],[20],[41] 8.50% [6],[7],[15],[16],[17],[20],[41] 8.50% [6],[7],[15],[16],[17],[20],[41] 8.50% [6],[7],[15],[16],[17],[20],[41] 8.50% [6],[7],[15],[16],[17],[20],[41] 8.50% [6],[7],[15],[16],[17],[20],[41] 8.50% [8],[9],[10],[11],[12],[22],[42] 8.50% [8],[9],[10],[11],[12],[22],[42] 8.50% [8],[9],[10],[11],[12],[22],[42] 8.50% [8],[9],[10],[11],[12],[22],[42] 8.50% [8],[9],[10],[11],[12],[22],[42] 8.50% [8],[9],[10],[11],[12],[22],[42] 8.50% [8],[9],[10],[11],[12],[22],[42]  
Base Rate Floor 1.00% [6],[7],[15],[16],[17],[20],[41] 1.00% [6],[7],[15],[16],[17],[20],[41] 1.00% [6],[7],[15],[16],[17],[20],[41] 1.00% [6],[7],[15],[16],[17],[20],[41] 1.00% [6],[7],[15],[16],[17],[20],[41] 1.00% [6],[7],[15],[16],[17],[20],[41] 1.00% [6],[7],[15],[16],[17],[20],[41] 1.00% [9],[10],[11],[12],[22],[42] 1.00% [9],[10],[11],[12],[22],[42] 1.00% [9],[10],[11],[12],[22],[42] 1.00% [9],[10],[11],[12],[22],[42] 1.00% [9],[10],[11],[12],[22],[42] 1.00% [9],[10],[11],[12],[22],[42] 1.00% [9],[10],[11],[12],[22],[42]  
Principal amount $ 174,000,000.0 [7],[13],[15],[16],[17],[20],[41]             $ 183,600,000 [9],[10],[11],[12],[14],[22],[42]              
Amortized Cost 167,400,000 [7],[15],[16],[17],[20],[41]             176,600,000 [9],[10],[11],[12],[22],[42]              
Fair Value $ (165,100,000) [4],[7],[15],[16],[17],[20],[41]             (175,000,000.0) [1],[9],[10],[11],[12],[22],[42]              
Investment, Identifier [Axis]: One Call Care Management Inc 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value [59]               0             (5,000,000.0)
Investment, Identifier [Axis]: One Call Care Management Inc 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value [59]               0             (23,500,000)
Investment, Identifier [Axis]: One Call Care Management Inc, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value [59]               $ 0             (2,400,000)
Investment, Identifier [Axis]: One Call Care Management Inc, Common Stock, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[32] 34,872 34,872 34,872 34,872 34,872 34,872 34,872 34,872 34,872 34,872 34,872 34,872 34,872 34,872  
Amortized Cost [7],[32] $ 2,100,000             $ 2,100,000              
Fair Value [7],[32] $ (1,300,000)             $ (1,900,000) [1]              
Investment, Identifier [Axis]: One Call Care Management Inc, Common Stock, Health Care Equipment & Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 34,873 34,873 34,873 34,873 34,873 34,873 34,873 34,873 34,873 34,873 34,873 34,873 34,873 34,873  
Amortized Cost $ 2,200,000             $ 2,200,000              
Fair Value $ (1,300,000)             $ (1,900,000)              
Investment, Identifier [Axis]: One Call Care Management Inc, Health Care Equipment & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[7],[39] 5.50% [6],[7],[39] 5.50% [6],[7],[39] 5.50% [6],[7],[39] 5.50% [6],[7],[39] 5.50% [6],[7],[39] 5.50% [6],[7],[39] 5.50% [8],[11],[40] 5.50% [8],[11],[40] 5.50% [8],[11],[40] 5.50% [8],[11],[40] 5.50% [8],[11],[40] 5.50% [8],[11],[40] 5.50% [8],[11],[40]  
Base Rate Floor 0.80% [6],[7],[39] 0.80% [6],[7],[39] 0.80% [6],[7],[39] 0.80% [6],[7],[39] 0.80% [6],[7],[39] 0.80% [6],[7],[39] 0.80% [6],[7],[39] 0.80% [11],[40] 0.80% [11],[40] 0.80% [11],[40] 0.80% [11],[40] 0.80% [11],[40] 0.80% [11],[40] 0.80% [11],[40]  
Principal amount $ 4,900,000 [7],[13],[39]             $ 4,900,000 [11],[14],[40]              
Amortized Cost 4,700,000 [7],[39]             4,700,000 [11],[40]              
Fair Value $ (3,700,000) [4],[7],[39]             $ (4,100,000) [1],[11],[40]              
Investment, Identifier [Axis]: One Call Care Management Inc, Health Care Equipment & Services 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 4,900,000             $ 4,900,000              
Amortized Cost 4,900,000             5,000,000.0              
Fair Value $ (3,700,000)             $ (4,100,000)              
Investment, Identifier [Axis]: One Call Care Management Inc, Health Care Equipment & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 8.50% [7] 8.50% [7] 8.50% [7] 8.50% [7] 8.50% [7] 8.50% [7] 8.50% [7] 8.50% [8],[11] 8.50% [8],[11] 8.50% [8],[11] 8.50% [8],[11] 8.50% [8],[11] 8.50% [8],[11] 8.50% [8],[11]  
Rate, Max PIK 8.50% [7] 8.50% [7] 8.50% [7] 8.50% [7] 8.50% [7] 8.50% [7] 8.50% [7] 8.50% [8],[11] 8.50% [8],[11] 8.50% [8],[11] 8.50% [8],[11] 8.50% [8],[11] 8.50% [8],[11] 8.50% [8],[11]  
Principal amount $ 25,600,000 [7]             $ 25,600,000 [11],[14]              
Amortized Cost 23,900,000 [7]             23,900,000 [11]              
Fair Value $ (18,800,000) [7]             $ (20,900,000) [1],[11]              
Investment, Identifier [Axis]: One Call Care Management Inc, Health Care Equipment & Services 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%  
Rate, Max PIK 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%  
Principal amount $ 25,600,000             $ 25,600,000              
Amortized Cost 25,100,000             25,000,000.0              
Fair Value $ (18,800,000)             (20,900,000)              
Investment, Identifier [Axis]: One Call Care Management Inc, Preferred Stock A                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value [59]               $ 0             (26,100,000)
Investment, Identifier [Axis]: One Call Care Management Inc, Preferred Stock A, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[32] 371,992 371,992 371,992 371,992 371,992 371,992 371,992 371,992 371,992 371,992 371,992 371,992 371,992 371,992  
Amortized Cost [7],[32] $ 22,800,000             $ 22,800,000              
Fair Value [7],[32] $ (17,700,000)             $ (20,500,000) [1]              
Investment, Identifier [Axis]: One Call Care Management Inc, Preferred Stock A, Health Care Equipment & Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 371,993 371,993 371,993 371,993 371,993 371,993 371,993 371,993 371,993 371,993 371,993 371,993 371,993 371,993  
Amortized Cost $ 23,700,000             $ 23,700,000              
Fair Value $ (17,700,000)             (20,600,000)              
Investment, Identifier [Axis]: One Call Care Management Inc, Preferred Stock B 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value [59]               $ 0             (9,200,000)
Investment, Identifier [Axis]: One Call Care Management Inc, Preferred Stock B, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 9.00% [7] 9.00% [7] 9.00% [7] 9.00% [7] 9.00% [7] 9.00% [7] 9.00% [7] 9.00% [27] 9.00% [27] 9.00% [27] 9.00% [27] 9.00% [27] 9.00% [27] 9.00% [27]  
Rate, Max PIK 9.00% [7] 9.00% [7] 9.00% [7] 9.00% [7] 9.00% [7] 9.00% [7] 9.00% [7] 9.00% [27] 9.00% [27] 9.00% [27] 9.00% [27] 9.00% [27] 9.00% [27] 9.00% [27]  
Number of Shares | shares 7,672,347 [7] 7,672,347 [7] 7,672,347 [7] 7,672,347 [7] 7,672,347 [7] 7,672,347 [7] 7,672,347 [7] 7,672,347 [27] 7,672,347 [27] 7,672,347 [27] 7,672,347 [27] 7,672,347 [27] 7,672,347 [27] 7,672,347 [27]  
Amortized Cost $ 8,000,000.0 [7]             $ 8,000,000.0 [27]              
Fair Value $ (7,700,000) [7]             $ (7,700,000) [1],[27]              
Investment, Identifier [Axis]: One Call Care Management Inc, Preferred Stock B, Health Care Equipment & Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%  
Rate, Max PIK 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%  
Number of Shares | shares 7,672,346 7,672,346 7,672,346 7,672,346 7,672,346 7,672,346 7,672,346 7,672,346 7,672,346 7,672,346 7,672,346 7,672,346 7,672,346 7,672,346  
Amortized Cost $ 8,700,000             $ 8,700,000              
Fair Value $ (7,700,000)             $ (7,700,000)              
Investment, Identifier [Axis]: Ontic Engineering & Manufacturing Inc, Capital Goods | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount $ 2,100,000             $ 2,100,000              
Amortized Cost 1,900,000             1,900,000              
Fair Value $ (2,100,000)             $ (2,100,000)              
Investment, Identifier [Axis]: Opendoor Labs Inc, Structured Mezzanine, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate [11],[28]               10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%  
Principal amount [11],[14],[28]               $ 71,100,000              
Amortized Cost [11],[28]               71,100,000              
Fair Value [1],[11],[28]               (66,400,000)              
Investment, Identifier [Axis]: Opendoor Labs Inc, Structured Mezzanine, Real Estate Management & Development                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate [7],[33] 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%                
Principal amount [7],[33] $ 56,900,000                            
Amortized Cost [7],[33] 56,900,000                            
Fair Value [7],[33] $ (54,100,000)                            
Investment, Identifier [Axis]: Orchard Marine Limited, Class B Common Stock, Asset Based Finance                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               0             0
Investment, Identifier [Axis]: Orchard Marine Limited, Series A Preferred Stock, Asset Based Finance                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ 0             (64,600,000)
Investment, Identifier [Axis]: Oxford Global Resources LLC, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[7],[16],[17],[20],[21],[41] 6.00% [6],[7],[16],[17],[20],[21],[41] 6.00% [6],[7],[16],[17],[20],[21],[41] 6.00% [6],[7],[16],[17],[20],[21],[41] 6.00% [6],[7],[16],[17],[20],[21],[41] 6.00% [6],[7],[16],[17],[20],[21],[41] 6.00% [6],[7],[16],[17],[20],[21],[41] 6.00% [8],[9],[10],[11],[22],[23],[42] 6.00% [8],[9],[10],[11],[22],[23],[42] 6.00% [8],[9],[10],[11],[22],[23],[42] 6.00% [8],[9],[10],[11],[22],[23],[42] 6.00% [8],[9],[10],[11],[22],[23],[42] 6.00% [8],[9],[10],[11],[22],[23],[42] 6.00% [8],[9],[10],[11],[22],[23],[42]  
Base Rate Floor 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42]  
Principal amount $ 87,300,000 [7],[13],[16],[17],[20],[21],[41]             $ 94,500,000 [9],[10],[11],[14],[22],[23],[42]              
Amortized Cost 86,600,000 [7],[16],[17],[20],[21],[41]             93,700,000 [9],[10],[11],[22],[23],[42]              
Fair Value $ (87,700,000) [4],[7],[16],[17],[20],[21],[41]             $ (94,100,000) [1],[9],[10],[11],[22],[23],[42]              
Investment, Identifier [Axis]: Oxford Global Resources LLC, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [8],[11] 6.00% [8],[11] 6.00% [8],[11] 6.00% [8],[11] 6.00% [8],[11] 6.00% [8],[11] 6.00% [8],[11]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Principal amount $ 3,100,000 [7],[13]             $ 3,500,000 [11],[14]              
Amortized Cost 3,100,000 [7]             3,500,000 [11]              
Fair Value $ (3,100,000) [4],[7]             $ (3,500,000) [1],[11]              
Investment, Identifier [Axis]: Oxford Global Resources LLC, Commercial & Professional Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 7,300,000 [7],[13]             $ 8,300,000 [14],[18]              
Amortized Cost 7,300,000 [7]             8,300,000 [18]              
Fair Value $ (7,300,000) [4],[7]             $ (8,300,000) [1],[18]              
Investment, Identifier [Axis]: Oxford Global Resources LLC, Commercial & Professional Services 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 4,600,000 [13],[19]             $ 4,100,000 [14],[18]              
Amortized Cost 4,600,000 [19]             4,100,000 [18]              
Fair Value $ (4,600,000) [4],[19]             (4,100,000) [1],[18]              
Investment, Identifier [Axis]: Oxford Global Resources LLC, Commercial & Professional Services 5                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base Rate Floor [6],[19] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[19] $ 8,000,000.0                            
Amortized Cost [19] 8,000,000.0                            
Fair Value [4],[19] (8,000,000.0)                            
Investment, Identifier [Axis]: PRG III LLC, Preferred Stock, Series A PIK                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (139,500,000)             $ (105,700,000)             (17,400,000)
Investment, Identifier [Axis]: PRG III LLC, Preferred Stock, Series A PIK, Media & Entertainment                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 434,250 [7],[32],[34] 434,250 [7],[32],[34] 434,250 [7],[32],[34] 434,250 [7],[32],[34] 434,250 [7],[32],[34] 434,250 [7],[32],[34] 434,250 [7],[32],[34] 434,250 [11],[27],[35] 434,250 [11],[27],[35] 434,250 [11],[27],[35] 434,250 [11],[27],[35] 434,250 [11],[27],[35] 434,250 [11],[27],[35] 434,250 [11],[27],[35]  
Amortized Cost $ 18,100,000 [7],[32],[34]             $ 18,100,000 [11],[27],[35]              
Fair Value (139,500,000) [7],[32],[34]             (105,700,000) [1],[11],[27],[35]              
Investment, Identifier [Axis]: PRG III LLC, Preferred Stock, Series B PIK                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ 0             $ 0             0
Investment, Identifier [Axis]: PRG III LLC, Preferred Stock, Series B PIK, Media & Entertainment                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 140 [7],[32],[34] 140 [7],[32],[34] 140 [7],[32],[34] 140 [7],[32],[34] 140 [7],[32],[34] 140 [7],[32],[34] 140 [7],[32],[34] 140 [11],[27],[35] 140 [11],[27],[35] 140 [11],[27],[35] 140 [11],[27],[35] 140 [11],[27],[35] 140 [11],[27],[35] 140 [11],[27],[35]  
Amortized Cost $ 0 [7],[32],[34]             $ 0 [11],[27],[35]              
Fair Value $ 0 [7],[32],[34]             $ 0 [1],[11],[27],[35]              
Investment, Identifier [Axis]: PSKW LLC (dba ConnectiveRx), Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[7],[15],[17],[21],[36],[41] 6.25% [6],[7],[15],[17],[21],[36],[41] 6.25% [6],[7],[15],[17],[21],[36],[41] 6.25% [6],[7],[15],[17],[21],[36],[41] 6.25% [6],[7],[15],[17],[21],[36],[41] 6.25% [6],[7],[15],[17],[21],[36],[41] 6.25% [6],[7],[15],[17],[21],[36],[41] 6.25% [8],[10],[11],[12],[23],[37] 6.25% [8],[10],[11],[12],[23],[37] 6.25% [8],[10],[11],[12],[23],[37] 6.25% [8],[10],[11],[12],[23],[37] 6.25% [8],[10],[11],[12],[23],[37] 6.25% [8],[10],[11],[12],[23],[37] 6.25% [8],[10],[11],[12],[23],[37]  
Base Rate Floor 1.00% [6],[7],[15],[17],[21],[36],[41] 1.00% [6],[7],[15],[17],[21],[36],[41] 1.00% [6],[7],[15],[17],[21],[36],[41] 1.00% [6],[7],[15],[17],[21],[36],[41] 1.00% [6],[7],[15],[17],[21],[36],[41] 1.00% [6],[7],[15],[17],[21],[36],[41] 1.00% [6],[7],[15],[17],[21],[36],[41] 1.00% [10],[11],[12],[23],[37] 1.00% [10],[11],[12],[23],[37] 1.00% [10],[11],[12],[23],[37] 1.00% [10],[11],[12],[23],[37] 1.00% [10],[11],[12],[23],[37] 1.00% [10],[11],[12],[23],[37] 1.00% [10],[11],[12],[23],[37]  
Principal amount $ 291,000,000.0 [7],[13],[15],[17],[21],[36],[41]             $ 291,800,000 [10],[11],[12],[14],[23],[37]              
Amortized Cost 282,600,000 [7],[15],[17],[21],[36],[41]             282,800,000 [10],[11],[12],[23],[37]              
Fair Value $ (291,000,000.0) [4],[7],[15],[17],[21],[36],[41]             $ (291,800,000) [1],[10],[11],[12],[23],[37]              
Investment, Identifier [Axis]: Pantherx Specialty LLC, Pharmaceuticals, Biotechnology & Life Sciences | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base Rate Floor 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount $ 15,900,000             $ 15,900,000              
Amortized Cost 14,800,000             14,800,000              
Fair Value $ (15,000,000.0)             $ (14,600,000)              
Investment, Identifier [Axis]: Paradigm Acquisition Corp, Health Care Equipment & Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount $ 2,500,000             $ 2,500,000              
Amortized Cost 2,500,000             2,500,000              
Fair Value $ (2,500,000)             $ (2,400,000)              
Investment, Identifier [Axis]: Parts Town LLC, Consumer Discretionary Distribution & Retail                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[21],[41] 5.98% 5.98% 5.98% 5.98% 5.98% 5.98% 5.98%                
Base Rate Floor [6],[7],[21],[41] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [7],[13],[21],[41] $ 100,100,000                            
Amortized Cost [7],[21],[41] 99,300,000                            
Fair Value [4],[7],[21],[41] $ (97,100,000)                            
Investment, Identifier [Axis]: Parts Town LLC, Consumer Discretionary Distribution & Retail | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.98% 5.98% 5.98% 5.98% 5.98% 5.98% 5.98%                
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount $ 49,300,000                            
Amortized Cost 48,200,000                            
Fair Value $ (47,800,000)                            
Investment, Identifier [Axis]: Parts Town LLC, Retailing | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base Rate Floor               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount               $ 49,400,000              
Amortized Cost               48,300,000              
Fair Value               $ (47,800,000)              
Investment, Identifier [Axis]: Parts Town LLC, Retailing 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11],[23]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base Rate Floor [11],[23]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [11],[14],[23]               $ 37,100,000              
Amortized Cost [11],[23]               36,800,000              
Fair Value [1],[11],[23]               $ (35,900,000)              
Investment, Identifier [Axis]: Parts Town LLC, Retailing 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base Rate Floor [11]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [11],[14]               $ 63,200,000              
Amortized Cost [11]               62,700,000              
Fair Value [1],[11]               $ (61,100,000)              
Investment, Identifier [Axis]: PartsSource Inc, Health Care Equipment & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 1,000,000.0 [7],[13]             $ 65,100,000 [11],[14]              
Amortized Cost 900,000 [7]             64,500,000 [11]              
Fair Value $ (900,000) [4],[7]             $ (62,900,000) [1],[11]              
Investment, Identifier [Axis]: PartsSource Inc, Health Care Equipment & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 64,900,000 [7],[13]             $ 4,300,000 [14],[18]              
Amortized Cost 64,300,000 [7]             4,300,000 [18]              
Fair Value $ (63,200,000) [4],[7]             $ (4,100,000) [1],[18]              
Investment, Identifier [Axis]: PartsSource Inc, Health Care Equipment & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 3,300,000 [13],[19]             $ 22,900,000 [14],[18]              
Amortized Cost 3,300,000 [19]             22,700,000 [18]              
Fair Value $ (3,200,000) [4],[19]             $ (22,100,000) [1],[18]              
Investment, Identifier [Axis]: PartsSource Inc, Health Care Equipment & Services 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base Rate Floor [6],[19] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[19] $ 22,900,000                            
Amortized Cost [19] 22,700,000                            
Fair Value [4],[19] $ (22,300,000)                            
Investment, Identifier [Axis]: Peraton Corp, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 8.00% [6],[7],[36] 8.00% [6],[7],[36] 8.00% [6],[7],[36] 8.00% [6],[7],[36] 8.00% [6],[7],[36] 8.00% [6],[7],[36] 8.00% [6],[7],[36] 8.00% [8],[11],[37] 8.00% [8],[11],[37] 8.00% [8],[11],[37] 8.00% [8],[11],[37] 8.00% [8],[11],[37] 8.00% [8],[11],[37] 8.00% [8],[11],[37]  
Base Rate Floor 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [6],[7],[36] 1.00% [11],[37] 1.00% [11],[37] 1.00% [11],[37] 1.00% [11],[37] 1.00% [11],[37] 1.00% [11],[37] 1.00% [11],[37]  
Principal amount $ 175,000,000.0 [7],[13],[36]             $ 175,000,000.0 [11],[14],[37]              
Amortized Cost 166,500,000 [7],[36]             166,200,000 [11],[37]              
Fair Value $ (176,800,000) [4],[7],[36]             $ (174,700,000) [1],[11],[37]              
Investment, Identifier [Axis]: Peraton Corp, Capital Goods 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 8,700,000             $ 8,800,000              
Amortized Cost 8,400,000             8,400,000              
Fair Value $ (8,700,000)             $ (8,600,000)              
Investment, Identifier [Axis]: Peraton Corp, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.75% [6],[7] 7.75% [6],[7] 7.75% [6],[7] 7.75% [6],[7] 7.75% [6],[7] 7.75% [6],[7] 7.75% [6],[7] 7.75% [8],[11] 7.75% [8],[11] 7.75% [8],[11] 7.75% [8],[11] 7.75% [8],[11] 7.75% [8],[11] 7.75% [8],[11]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 130,400,000 [7],[13]             $ 130,400,000 [11],[14]              
Amortized Cost 124,900,000 [7]             124,800,000 [11]              
Fair Value $ (130,400,000) [4],[7]             $ (128,800,000) [1],[11]              
Investment, Identifier [Axis]: Peraton Corp, Capital Goods 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 21,500,000             $ 21,500,000              
Amortized Cost 21,300,000             21,300,000              
Fair Value $ (21,500,000)             $ (21,200,000)              
Investment, Identifier [Axis]: Performance Health Holdings Inc, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[7],[15],[20],[41] 6.00% [6],[7],[15],[20],[41] 6.00% [6],[7],[15],[20],[41] 6.00% [6],[7],[15],[20],[41] 6.00% [6],[7],[15],[20],[41] 6.00% [6],[7],[15],[20],[41] 6.00% [6],[7],[15],[20],[41] 6.00% [8],[11],[12],[22],[42] 6.00% [8],[11],[12],[22],[42] 6.00% [8],[11],[12],[22],[42] 6.00% [8],[11],[12],[22],[42] 6.00% [8],[11],[12],[22],[42] 6.00% [8],[11],[12],[22],[42] 6.00% [8],[11],[12],[22],[42]  
Base Rate Floor 1.00% [6],[7],[15],[20],[41] 1.00% [6],[7],[15],[20],[41] 1.00% [6],[7],[15],[20],[41] 1.00% [6],[7],[15],[20],[41] 1.00% [6],[7],[15],[20],[41] 1.00% [6],[7],[15],[20],[41] 1.00% [6],[7],[15],[20],[41] 1.00% [11],[12],[22],[42] 1.00% [11],[12],[22],[42] 1.00% [11],[12],[22],[42] 1.00% [11],[12],[22],[42] 1.00% [11],[12],[22],[42] 1.00% [11],[12],[22],[42] 1.00% [11],[12],[22],[42]  
Principal amount $ 108,300,000 [7],[13],[15],[20],[41]             $ 108,300,000 [11],[12],[14],[22],[42]              
Amortized Cost 107,400,000 [7],[15],[20],[41]             107,400,000 [11],[12],[22],[42]              
Fair Value $ (106,300,000) [4],[7],[15],[20],[41]             (105,400,000) [1],[11],[12],[22],[42]              
Investment, Identifier [Axis]: Petroplex Acidizing Inc, Preferred Stock A, Equity/Other                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               0             0
Investment, Identifier [Axis]: Petroplex Acidizing Inc, Senior Secured Loans—First Lien                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ 0             (9,700,000)
Investment, Identifier [Axis]: Petroplex Acidizing Inc, Trade Claim, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[32] 589,656 589,656 589,656 589,656 589,656 589,656 589,656 646,309 646,309 646,309 646,309 646,309 646,309 646,309  
Amortized Cost [7],[32] $ 600,000             $ 600,000              
Fair Value [7],[32] $ (300,000)             $ (600,000) [1]              
Investment, Identifier [Axis]: Plaskolite, LLC, Materials | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 1,100,000             $ 1,100,000              
Amortized Cost 1,100,000             1,100,000              
Fair Value $ (1,000,000.0)             $ (1,000,000.0)              
Investment, Identifier [Axis]: Polyconcept North America Inc, Class A - 1 Units, Household & Personal Products                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 30,000 [7] 30,000 [7] 30,000 [7] 30,000 [7] 30,000 [7] 30,000 [7] 30,000 [7] 30,000 [11] 30,000 [11] 30,000 [11] 30,000 [11] 30,000 [11] 30,000 [11] 30,000 [11]  
Amortized Cost $ 3,000,000.0 [7]             $ 3,000,000.0 [11]              
Fair Value $ (10,300,000) [7]             $ (10,300,000) [1],[11]              
Investment, Identifier [Axis]: Precision Global Corp, Materials | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 4.75% 4.75% 4.75% 4.75% 4.75% 4.75% 4.75% 4.75% 4.75% 4.75% 4.75% 4.75% 4.75% 4.75%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 8,900,000             $ 8,900,000              
Amortized Cost 8,700,000             8,700,000              
Fair Value $ (8,800,000)             $ (8,800,000)              
Investment, Identifier [Axis]: Pretium Packaging LLC, Household & Personal Products 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00%  
Base Rate Floor 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount $ 1,600,000             $ 1,600,000              
Amortized Cost 1,600,000             1,600,000              
Fair Value $ (1,300,000)             $ (1,300,000)              
Investment, Identifier [Axis]: Pretium Packaging LLC, Household & Personal Products 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%  
Base Rate Floor 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount $ 39,900,000             $ 39,900,000              
Amortized Cost 39,700,000             39,700,000              
Fair Value $ (30,900,000)             (31,600,000)              
Investment, Identifier [Axis]: Pretium Partners LLC P1, Structured Mezzanine, Equity Real Estate Investment Trusts (REITs) | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 530.00% 530.00% 530.00% 530.00% 530.00% 530.00% 530.00%                
Rate, Max PIK 530.00% 530.00% 530.00% 530.00% 530.00% 530.00% 530.00%                
Rate, Stated interest rate 2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80%                
Principal amount $ 30,400,000                            
Amortized Cost 29,400,000                            
Fair Value $ (29,500,000)                            
Investment, Identifier [Axis]: Pretium Partners LLC P1, Structured Mezzanine, Real Estate | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount               29,600,000              
Amortized Cost               28,600,000              
Fair Value               $ (28,300,000)              
Investment, Identifier [Axis]: Pretium Partners LLC P2, Private Equity, Equity Real Estate Investment Trusts (REITs) | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 16,772,368 16,772,368 16,772,368 16,772,368 16,772,368 16,772,368 16,772,368                
Amortized Cost $ 16,200,000                            
Fair Value $ (18,400,000)                            
Investment, Identifier [Axis]: Pretium Partners LLC P2, Private Equity, Real Estate | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares               16,772,368 16,772,368 16,772,368 16,772,368 16,772,368 16,772,368 16,772,368  
Amortized Cost               $ 16,200,000              
Fair Value               $ (13,700,000)              
Investment, Identifier [Axis]: Pretium Partners LLC P2, Term Loan, Equity Real Estate Investment Trusts (REITs) | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate 11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%                
Principal amount $ 33,500,000                            
Amortized Cost 32,900,000                            
Fair Value $ (32,900,000)                            
Investment, Identifier [Axis]: Pretium Partners LLC P2, Term Loan, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate [11],[28]               11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%  
Principal amount [11],[14],[28]               $ 33,500,000              
Amortized Cost [11],[28]               33,000,000.0              
Fair Value [1],[11],[28]               $ (32,900,000)              
Investment, Identifier [Axis]: Prime ST LLC, Private Equity, Equity Real Estate Investment Trusts (REITs)                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[32],[33],[34] 5,612,193 5,612,193 5,612,193 5,612,193 5,612,193 5,612,193 5,612,193                
Amortized Cost [7],[32],[33],[34] $ 7,300,000                            
Fair Value [7],[32],[33],[34] $ 0                            
Investment, Identifier [Axis]: Prime ST LLC, Private Equity, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [11],[14],[27],[28],[35]               5,666,079 5,666,079 5,666,079 5,666,079 5,666,079 5,666,079 5,666,079  
Amortized Cost [11],[27],[28],[35]               $ 7,400,000              
Fair Value [1],[11],[27],[28],[35]               $ 0              
Investment, Identifier [Axis]: Prime ST LLC, Structured Mezzanine, Equity Real Estate Investment Trusts (REITs)                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK [7],[33],[34] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Rate, Max PIK [7],[33],[34] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Rate, Stated interest rate [7],[33],[34] 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%                
Principal amount [7],[33],[34] $ 55,500,000                            
Amortized Cost [7],[33],[34] 53,700,000                            
Fair Value [7],[33],[34] (39,600,000)                            
Investment, Identifier [Axis]: Prime ST LLC, Structured Mezzanine, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK [11],[28],[35]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Rate, Max PIK [11],[28],[35]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Rate, Stated interest rate [11],[28],[35]               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Principal amount [11],[14],[28],[35]               $ 55,500,000              
Amortized Cost [11],[28],[35]               53,700,000              
Fair Value [1],[11],[28],[35]               (43,500,000)              
Investment, Identifier [Axis]: Prime St LLC, Private Equity                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value 0             0             (9,100,000)
Investment, Identifier [Axis]: Prime St LLC, Structured Mezzanine                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value (39,600,000)             (43,500,000)             (52,400,000)
Investment, Identifier [Axis]: Production Resource Group LLC 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value (156,200,000)             (152,500,000)             (133,300,000)
Investment, Identifier [Axis]: Production Resource Group LLC 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value (100,000)             (100,000)             (100,000)
Investment, Identifier [Axis]: Production Resource Group LLC 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value (67,800,000)             (68,100,000)             (64,400,000)
Investment, Identifier [Axis]: Production Resource Group LLC 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (31,100,000)             $ (31,300,000)             (20,200,000)
Investment, Identifier [Axis]: Production Resource Group LLC, Media & Entertainment 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.00% [6],[7],[34] 5.00% [6],[7],[34] 5.00% [6],[7],[34] 5.00% [6],[7],[34] 5.00% [6],[7],[34] 5.00% [6],[7],[34] 5.00% [6],[7],[34] 5.00% [8],[11],[35] 5.00% [8],[11],[35] 5.00% [8],[11],[35] 5.00% [8],[11],[35] 5.00% [8],[11],[35] 5.00% [8],[11],[35] 5.00% [8],[11],[35]  
Rate, PIK 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [8],[11],[35] 3.10% [8],[11],[35] 3.10% [8],[11],[35] 3.10% [8],[11],[35] 3.10% [8],[11],[35] 3.10% [8],[11],[35] 3.10% [8],[11],[35]  
Rate, Max PIK 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [8],[11],[35] 3.10% [8],[11],[35] 3.10% [8],[11],[35] 3.10% [8],[11],[35] 3.10% [8],[11],[35] 3.10% [8],[11],[35] 3.10% [8],[11],[35]  
Base Rate Floor 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35]  
Principal amount $ 62,400,000 [7],[13],[34]             $ 62,700,000 [11],[14],[35]              
Amortized Cost 60,100,000 [7],[34]             59,900,000 [11],[35]              
Fair Value $ (64,300,000) [4],[7],[34]             $ (64,600,000) [1],[11],[35]              
Investment, Identifier [Axis]: Production Resource Group LLC, Media & Entertainment 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 3.00% [6],[7],[34] 3.00% [6],[7],[34] 3.00% [6],[7],[34] 3.00% [6],[7],[34] 3.00% [6],[7],[34] 3.00% [6],[7],[34] 3.00% [6],[7],[34] 3.00% [8],[11],[35] 3.00% [8],[11],[35] 3.00% [8],[11],[35] 3.00% [8],[11],[35] 3.00% [8],[11],[35] 3.00% [8],[11],[35] 3.00% [8],[11],[35]  
Rate, PIK 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [8],[11],[35] 5.50% [8],[11],[35] 5.50% [8],[11],[35] 5.50% [8],[11],[35] 5.50% [8],[11],[35] 5.50% [8],[11],[35] 5.50% [8],[11],[35]  
Rate, Max PIK 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [8],[11],[35] 5.50% [8],[11],[35] 5.50% [8],[11],[35] 5.50% [8],[11],[35] 5.50% [8],[11],[35] 5.50% [8],[11],[35] 5.50% [8],[11],[35]  
Base Rate Floor 0.30% [6],[7],[34] 0.30% [6],[7],[34] 0.30% [6],[7],[34] 0.30% [6],[7],[34] 0.30% [6],[7],[34] 0.30% [6],[7],[34] 0.30% [6],[7],[34] 0.30% [11],[35] 0.30% [11],[35] 0.30% [11],[35] 0.30% [11],[35] 0.30% [11],[35] 0.30% [11],[35] 0.30% [11],[35]  
Principal amount $ 153,100,000 [7],[13],[34]             $ 149,600,000 [11],[14],[35]              
Amortized Cost 148,200,000 [7],[34]             143,900,000 [11],[35]              
Fair Value $ (156,200,000) [4],[7],[34]             $ (152,500,000) [1],[11],[35]              
Investment, Identifier [Axis]: Production Resource Group LLC, Media & Entertainment 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [8],[11],[35] 5.50% [8],[11],[35] 5.50% [8],[11],[35] 5.50% [8],[11],[35] 5.50% [8],[11],[35] 5.50% [8],[11],[35] 5.50% [8],[11],[35]  
Rate, Max PIK 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [6],[7],[34] 5.50% [8],[11],[35] 5.50% [8],[11],[35] 5.50% [8],[11],[35] 5.50% [8],[11],[35] 5.50% [8],[11],[35] 5.50% [8],[11],[35] 5.50% [8],[11],[35]  
Base Rate Floor 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35]  
Principal amount $ 100,000 [7],[13],[34]             $ 100,000 [11],[14],[35]              
Amortized Cost 100,000 [7],[34]             100,000 [11],[35]              
Fair Value $ (100,000) [4],[7],[34]             $ (100,000) [1],[11],[35]              
Investment, Identifier [Axis]: Production Resource Group LLC, Media & Entertainment 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.00% [6],[7],[34] 5.00% [6],[7],[34] 5.00% [6],[7],[34] 5.00% [6],[7],[34] 5.00% [6],[7],[34] 5.00% [6],[7],[34] 5.00% [6],[7],[34] 5.00% [8],[11],[35] 5.00% [8],[11],[35] 5.00% [8],[11],[35] 5.00% [8],[11],[35] 5.00% [8],[11],[35] 5.00% [8],[11],[35] 5.00% [8],[11],[35]  
Rate, PIK 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [8],[11],[35] 3.10% [8],[11],[35] 3.10% [8],[11],[35] 3.10% [8],[11],[35] 3.10% [8],[11],[35] 3.10% [8],[11],[35] 3.10% [8],[11],[35]  
Rate, Max PIK 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [6],[7],[34] 3.10% [8],[11],[35] 3.10% [8],[11],[35] 3.10% [8],[11],[35] 3.10% [8],[11],[35] 3.10% [8],[11],[35] 3.10% [8],[11],[35] 3.10% [8],[11],[35]  
Base Rate Floor 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35] 1.00% [11],[35]  
Principal amount $ 34,300,000 [7],[13],[34]             $ 34,400,000 [11],[14],[35]              
Amortized Cost 34,200,000 [7],[34]             34,300,000 [11],[35]              
Fair Value $ (34,600,000) [4],[7],[34]             (34,800,000) [1],[11],[35]              
Investment, Identifier [Axis]: Project Marron, Consumer Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ (52,000,000.0)              
Investment, Identifier [Axis]: Project Marron, Consumer Services 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base Rate Floor 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount           $ 81.8             $ 81.8    
Amortized Cost $ 56,500,000             $ 56,400,000              
Fair Value $ (50,600,000)                            
Investment, Identifier [Axis]: Project Marron, Consumer Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ (36,300,000)              
Investment, Identifier [Axis]: Project Marron, Consumer Services 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base Rate Floor 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount             $ 52.5             $ 52.5  
Amortized Cost $ 40,200,000             $ 40,100,000              
Fair Value (35,900,000)                            
Investment, Identifier [Axis]: Proserv Acquisition LLC, Class A Common Units                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (1,900,000)             $ (1,100,000)              
Investment, Identifier [Axis]: Proserv Acquisition LLC, Class A Common Units, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 2,635,005 [7],[32],[33],[43] 2,635,005 [7],[32],[33],[43] 2,635,005 [7],[32],[33],[43] 2,635,005 [7],[32],[33],[43] 2,635,005 [7],[32],[33],[43] 2,635,005 [7],[32],[33],[43] 2,635,005 [7],[32],[33],[43] 2,635,005 [11],[27],[28],[44] 2,635,005 [11],[27],[28],[44] 2,635,005 [11],[27],[28],[44] 2,635,005 [11],[27],[28],[44] 2,635,005 [11],[27],[28],[44] 2,635,005 [11],[27],[28],[44] 2,635,005 [11],[27],[28],[44]  
Amortized Cost $ 33,500,000 [7],[32],[33],[43]             $ 33,500,000 [11],[27],[28],[44]              
Fair Value (1,900,000) [7],[32],[33],[43]             (1,100,000) [1],[11],[27],[28],[44]              
Investment, Identifier [Axis]: Proserv Acquisition LLC, Class A Common Units, Equity/Other                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               (1,100,000)             (100,000)
Investment, Identifier [Axis]: Proserv Acquisition LLC, Class A Preferred Units                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (9,500,000)             $ (9,500,000)              
Investment, Identifier [Axis]: Proserv Acquisition LLC, Class A Preferred Units, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 837,780 [7],[32],[33],[43] 837,780 [7],[32],[33],[43] 837,780 [7],[32],[33],[43] 837,780 [7],[32],[33],[43] 837,780 [7],[32],[33],[43] 837,780 [7],[32],[33],[43] 837,780 [7],[32],[33],[43] 837,780 [11],[27],[28],[44] 837,780 [11],[27],[28],[44] 837,780 [11],[27],[28],[44] 837,780 [11],[27],[28],[44] 837,780 [11],[27],[28],[44] 837,780 [11],[27],[28],[44] 837,780 [11],[27],[28],[44]  
Amortized Cost $ 5,400,000 [7],[32],[33],[43]             $ 5,400,000 [11],[27],[28],[44]              
Fair Value $ (9,500,000) [7],[32],[33],[43]             (9,500,000) [1],[11],[27],[28],[44]              
Investment, Identifier [Axis]: Proserv Acquisition LLC, Class A Preferred Units, Equity/Other                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ (9,500,000)             (9,300,000)
Investment, Identifier [Axis]: Pure Fishing Inc, Consumer Durables & Apparel 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 4.50% [6],[7],[39] 4.50% [6],[7],[39] 4.50% [6],[7],[39] 4.50% [6],[7],[39] 4.50% [6],[7],[39] 4.50% [6],[7],[39] 4.50% [6],[7],[39] 4.50% [8],[11],[40] 4.50% [8],[11],[40] 4.50% [8],[11],[40] 4.50% [8],[11],[40] 4.50% [8],[11],[40] 4.50% [8],[11],[40] 4.50% [8],[11],[40]  
Base Rate Floor 0.00% [6],[7],[39] 0.00% [6],[7],[39] 0.00% [6],[7],[39] 0.00% [6],[7],[39] 0.00% [6],[7],[39] 0.00% [6],[7],[39] 0.00% [6],[7],[39] 0.00% [11],[40] 0.00% [11],[40] 0.00% [11],[40] 0.00% [11],[40] 0.00% [11],[40] 0.00% [11],[40] 0.00% [11],[40]  
Principal amount $ 33,600,000 [7],[13],[39]             $ 33,700,000 [11],[14],[40]              
Amortized Cost 33,100,000 [7],[39]             33,200,000 [11],[40]              
Fair Value $ (20,900,000) [4],[7],[39]             $ (22,600,000) [1],[11],[40]              
Investment, Identifier [Axis]: Pure Fishing Inc, Consumer Durables & Apparel 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 4.50%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount $ 9,800,000             $ 9,800,000              
Amortized Cost 9,700,000             9,700,000              
Fair Value $ (6,100,000)             $ (6,600,000)              
Investment, Identifier [Axis]: Pure Fishing Inc, Consumer Durables & Apparel 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 8.38% [6],[7] 8.38% [6],[7] 8.38% [6],[7] 8.38% [6],[7] 8.38% [6],[7] 8.38% [6],[7] 8.38% [6],[7] 8.38% [8],[11],[42] 8.38% [8],[11],[42] 8.38% [8],[11],[42] 8.38% [8],[11],[42] 8.38% [8],[11],[42] 8.38% [8],[11],[42] 8.38% [8],[11],[42]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42]  
Principal amount $ 100,000,000.0 [7],[13]             $ 100,000,000.0 [11],[14],[42]              
Amortized Cost 95,500,000 [7]             95,300,000 [11],[42]              
Fair Value $ (54,300,000) [4],[7]             $ (56,100,000) [1],[11],[42]              
Investment, Identifier [Axis]: Pure Fishing Inc, Consumer Durables & Apparel 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 8.38% 8.38% 8.38% 8.38% 8.38% 8.38% 8.38% 8.38% 8.38% 8.38% 8.38% 8.38% 8.38% 8.38%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 26,500,000             $ 26,500,000              
Amortized Cost 24,300,000             24,200,000              
Fair Value $ (14,400,000)             $ (14,800,000)              
Investment, Identifier [Axis]: Pure Gym Ltd, Private Equity, Consumer Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 30,218,000 30,218,000 30,218,000 30,218,000 30,218,000 30,218,000 30,218,000 30,218,000 30,218,000 30,218,000 30,218,000 30,218,000 30,218,000 30,218,000  
Amortized Cost $ 39,400,000             $ 39,400,000              
Fair Value $ (41,100,000)             $ (39,200,000)              
Investment, Identifier [Axis]: Quorum Health Corp, Trade Claim, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[32] 8,301,000 8,301,000 8,301,000 8,301,000 8,301,000 8,301,000 8,301,000 8,301,000 8,301,000 8,301,000 8,301,000 8,301,000 8,301,000 8,301,000  
Amortized Cost [7],[32] $ 700,000             $ 700,000              
Fair Value [7],[32] $ (900,000)             $ (900,000) [1]              
Investment, Identifier [Axis]: Quorum Health Corp, Trust Initial Funding Units, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[32] 143,400 143,400 143,400 143,400 143,400 143,400 143,400 143,400 [33],[53],[55] 143,400 [33],[53],[55] 143,400 [33],[53],[55] 143,400 [33],[53],[55] 143,400 [33],[53],[55] 143,400 [33],[53],[55] 143,400 [33],[53],[55]  
Amortized Cost [7],[32] $ 200,000             $ 200,000 [33],[53],[55]              
Fair Value [7],[32] $ (200,000)             $ (200,000) [1],[33],[53],[55]              
Investment, Identifier [Axis]: RSC Insurance Brokerage Inc, Insurance | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 18,800,000             $ 18,800,000              
Amortized Cost 18,700,000             18,800,000              
Fair Value $ (18,400,000)             $ (18,500,000)              
Investment, Identifier [Axis]: RSC Insurance Brokerage Inc, Insurance 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[7],[15],[16],[17],[36] 5.50% [6],[7],[15],[16],[17],[36] 5.50% [6],[7],[15],[16],[17],[36] 5.50% [6],[7],[15],[16],[17],[36] 5.50% [6],[7],[15],[16],[17],[36] 5.50% [6],[7],[15],[16],[17],[36] 5.50% [6],[7],[15],[16],[17],[36] 5.50% [8],[9],[10],[11],[12],[37],[42] 5.50% [8],[9],[10],[11],[12],[37],[42] 5.50% [8],[9],[10],[11],[12],[37],[42] 5.50% [8],[9],[10],[11],[12],[37],[42] 5.50% [8],[9],[10],[11],[12],[37],[42] 5.50% [8],[9],[10],[11],[12],[37],[42] 5.50% [8],[9],[10],[11],[12],[37],[42]  
Base Rate Floor 0.80% [6],[7],[15],[16],[17],[36] 0.80% [6],[7],[15],[16],[17],[36] 0.80% [6],[7],[15],[16],[17],[36] 0.80% [6],[7],[15],[16],[17],[36] 0.80% [6],[7],[15],[16],[17],[36] 0.80% [6],[7],[15],[16],[17],[36] 0.80% [6],[7],[15],[16],[17],[36] 0.80% [9],[10],[11],[12],[37],[42] 0.80% [9],[10],[11],[12],[37],[42] 0.80% [9],[10],[11],[12],[37],[42] 0.80% [9],[10],[11],[12],[37],[42] 0.80% [9],[10],[11],[12],[37],[42] 0.80% [9],[10],[11],[12],[37],[42] 0.80% [9],[10],[11],[12],[37],[42]  
Principal amount $ 239,400,000 [7],[13],[15],[16],[17],[36]             $ 240,000,000.0 [9],[10],[11],[12],[14],[37],[42]              
Amortized Cost 234,000,000.0 [7],[15],[16],[17],[36]             234,300,000 [9],[10],[11],[12],[37],[42]              
Fair Value $ (235,300,000) [4],[7],[15],[16],[17],[36]             $ (236,000,000.0) [1],[9],[10],[11],[12],[37],[42]              
Investment, Identifier [Axis]: RSC Insurance Brokerage Inc, Insurance 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [6],[7] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 4,800,000 [7],[13]             $ 7,700,000 [14],[18]              
Amortized Cost 4,700,000 [7]             7,600,000 [18]              
Fair Value $ (4,700,000) [4],[7]             $ (7,600,000) [1],[18]              
Investment, Identifier [Axis]: RSC Insurance Brokerage Inc, Insurance 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base Rate Floor [6],[19] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[19] $ 3,000,000.0                            
Amortized Cost [19] 3,000,000.0                            
Fair Value [4],[19] $ (2,900,000)                            
Investment, Identifier [Axis]: Radwell International LLC/PA, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.75% [6],[7] 6.75% [6],[7] 6.75% [6],[7] 6.75% [6],[7] 6.75% [6],[7] 6.75% [6],[7] 6.75% [6],[7] 6.53% [8],[11] 6.53% [8],[11] 6.53% [8],[11] 6.53% [8],[11] 6.53% [8],[11] 6.53% [8],[11] 6.53% [8],[11]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 900,000 [7],[13]             $ 1,000,000.0 [11],[14]              
Amortized Cost 900,000 [7]             1,000,000.0 [11]              
Fair Value $ (900,000) [4],[7]             $ (1,000,000.0) [1],[11]              
Investment, Identifier [Axis]: Radwell International LLC/PA, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.53% [6],[41] 6.53% [6],[41] 6.53% [6],[41] 6.53% [6],[41] 6.53% [6],[41] 6.53% [6],[41] 6.53% [6],[41] 6.75% [8],[9],[10],[12],[23] 6.75% [8],[9],[10],[12],[23] 6.75% [8],[9],[10],[12],[23] 6.75% [8],[9],[10],[12],[23] 6.75% [8],[9],[10],[12],[23] 6.75% [8],[9],[10],[12],[23] 6.75% [8],[9],[10],[12],[23]  
Base Rate Floor 0.80% [6],[41] 0.80% [6],[41] 0.80% [6],[41] 0.80% [6],[41] 0.80% [6],[41] 0.80% [6],[41] 0.80% [6],[41] 0.80% [9],[10],[12],[23] 0.80% [9],[10],[12],[23] 0.80% [9],[10],[12],[23] 0.80% [9],[10],[12],[23] 0.80% [9],[10],[12],[23] 0.80% [9],[10],[12],[23] 0.80% [9],[10],[12],[23]  
Principal amount $ 1,000,000.0 [13],[41]             $ 92,100,000 [9],[10],[12],[14],[23]              
Amortized Cost 1,000,000.0 [41]             92,100,000 [9],[10],[12],[23]              
Fair Value $ (1,000,000.0) [4],[41]             $ (92,100,000) [1],[9],[10],[12],[23]              
Investment, Identifier [Axis]: Radwell International LLC/PA, Capital Goods 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.75% [6],[15],[16],[17],[21] 6.75% [6],[15],[16],[17],[21] 6.75% [6],[15],[16],[17],[21] 6.75% [6],[15],[16],[17],[21] 6.75% [6],[15],[16],[17],[21] 6.75% [6],[15],[16],[17],[21] 6.75% [6],[15],[16],[17],[21] 6.75% [8],[18] 6.75% [8],[18] 6.75% [8],[18] 6.75% [8],[18] 6.75% [8],[18] 6.75% [8],[18] 6.75% [8],[18]  
Base Rate Floor 0.80% [6],[15],[16],[17],[21] 0.80% [6],[15],[16],[17],[21] 0.80% [6],[15],[16],[17],[21] 0.80% [6],[15],[16],[17],[21] 0.80% [6],[15],[16],[17],[21] 0.80% [6],[15],[16],[17],[21] 0.80% [6],[15],[16],[17],[21] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 91,900,000 [13],[15],[16],[17],[21]             $ 6,900,000 [14],[18]              
Amortized Cost 91,900,000 [15],[16],[17],[21]             6,900,000 [18]              
Fair Value $ (92,500,000) [4],[15],[16],[17],[21]             $ (6,900,000) [1],[18]              
Investment, Identifier [Axis]: Radwell International LLC/PA, Capital Goods 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19] 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%                
Base Rate Floor [6],[19] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[19] $ 6,000,000.0                            
Amortized Cost [19] 6,000,000.0                            
Fair Value [4],[19] $ (6,000,000.0)                            
Investment, Identifier [Axis]: Reliant Rehab Hospital Cincinnati LLC, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[7],[15],[17],[20],[36] 6.25% [6],[7],[15],[17],[20],[36] 6.25% [6],[7],[15],[17],[20],[36] 6.25% [6],[7],[15],[17],[20],[36] 6.25% [6],[7],[15],[17],[20],[36] 6.25% [6],[7],[15],[17],[20],[36] 6.25% [6],[7],[15],[17],[20],[36] 6.25% [8],[10],[11],[12],[22],[37],[42] 6.25% [8],[10],[11],[12],[22],[37],[42] 6.25% [8],[10],[11],[12],[22],[37],[42] 6.25% [8],[10],[11],[12],[22],[37],[42] 6.25% [8],[10],[11],[12],[22],[37],[42] 6.25% [8],[10],[11],[12],[22],[37],[42] 6.25% [8],[10],[11],[12],[22],[37],[42]  
Base Rate Floor 0.00% [6],[7],[15],[17],[20],[36] 0.00% [6],[7],[15],[17],[20],[36] 0.00% [6],[7],[15],[17],[20],[36] 0.00% [6],[7],[15],[17],[20],[36] 0.00% [6],[7],[15],[17],[20],[36] 0.00% [6],[7],[15],[17],[20],[36] 0.00% [6],[7],[15],[17],[20],[36] 0.00% [10],[11],[12],[22],[37],[42] 0.00% [10],[11],[12],[22],[37],[42] 0.00% [10],[11],[12],[22],[37],[42] 0.00% [10],[11],[12],[22],[37],[42] 0.00% [10],[11],[12],[22],[37],[42] 0.00% [10],[11],[12],[22],[37],[42] 0.00% [10],[11],[12],[22],[37],[42]  
Principal amount $ 105,100,000 [7],[13],[15],[17],[20],[36]             $ 106,100,000 [10],[11],[12],[14],[22],[37],[42]              
Amortized Cost 100,500,000 [7],[15],[17],[20],[36]             101,100,000 [10],[11],[12],[22],[37],[42]              
Fair Value $ (69,800,000) [4],[7],[15],[17],[20],[36]             $ (84,200,000) [1],[10],[11],[12],[22],[37],[42]              
Investment, Identifier [Axis]: Reliant Rehab Hospital Cincinnati LLC, Health Care Equipment & Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount $ 33,300,000             $ 33,600,000              
Amortized Cost 32,400,000             32,700,000              
Fair Value $ (22,100,000)             $ (26,700,000)              
Investment, Identifier [Axis]: Revere Superior Holdings Inc, Software & Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 19,500,000             $ 19,600,000              
Amortized Cost 19,500,000             19,600,000              
Fair Value $ (19,300,000)             $ (19,600,000)              
Investment, Identifier [Axis]: Revere Superior Holdings Inc, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[7],[41] 5.75% [6],[7],[41] 5.75% [6],[7],[41] 5.75% [6],[7],[41] 5.75% [6],[7],[41] 5.75% [6],[7],[41] 5.75% [6],[7],[41] 5.75% [8],[11],[42] 5.75% [8],[11],[42] 5.75% [8],[11],[42] 5.75% [8],[11],[42] 5.75% [8],[11],[42] 5.75% [8],[11],[42] 5.75% [8],[11],[42]  
Base Rate Floor 1.00% [6],[7],[41] 1.00% [6],[7],[41] 1.00% [6],[7],[41] 1.00% [6],[7],[41] 1.00% [6],[7],[41] 1.00% [6],[7],[41] 1.00% [6],[7],[41] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42]  
Principal amount $ 33,400,000 [7],[13],[41]             $ 33,500,000 [11],[14],[42]              
Amortized Cost 32,800,000 [7],[41]             32,900,000 [11],[42]              
Fair Value $ (33,000,000.0) [4],[7],[41]             $ (33,500,000) [1],[11],[42]              
Investment, Identifier [Axis]: Revere Superior Holdings Inc, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Principal amount $ 3,200,000 [13],[19]             $ 1,500,000 [11],[14]              
Amortized Cost 3,200,000 [19]             1,500,000 [11]              
Fair Value $ (3,200,000) [4],[19]             $ (1,500,000) [1],[11]              
Investment, Identifier [Axis]: Revere Superior Holdings Inc, Software & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[18]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base Rate Floor [18]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [14],[18]               $ 1,700,000              
Amortized Cost [18]               1,700,000              
Fair Value [1],[18]               $ (1,700,000)              
Investment, Identifier [Axis]: Ridgeback Resources Inc, Common Stock, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[33],[53],[55]               1,969,418 1,969,418 1,969,418 1,969,418 1,969,418 1,969,418 1,969,418  
Amortized Cost [7],[33],[53],[55]               $ 6,400,000              
Fair Value [1],[7],[33],[53],[55]               $ (8,600,000)              
Investment, Identifier [Axis]: Rise Baking Company, Food, Beverage & Tobacco 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Principal amount $ 700,000 [7],[13]             $ 1,400,000 [11],[14]              
Amortized Cost 600,000 [7]             1,300,000 [11]              
Fair Value $ (600,000) [4],[7]             $ (1,300,000) [1],[11]              
Investment, Identifier [Axis]: Rise Baking Company, Food, Beverage & Tobacco 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 200,000             $ 500,000              
Amortized Cost 200,000             500,000              
Fair Value $ (200,000)             $ (500,000)              
Investment, Identifier [Axis]: Rise Baking Company, Food, Beverage & Tobacco 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[7],[17],[41] 6.50% [6],[7],[17],[41] 6.50% [6],[7],[17],[41] 6.50% [6],[7],[17],[41] 6.50% [6],[7],[17],[41] 6.50% [6],[7],[17],[41] 6.50% [6],[7],[17],[41] 6.50% [8],[10],[42] 6.50% [8],[10],[42] 6.50% [8],[10],[42] 6.50% [8],[10],[42] 6.50% [8],[10],[42] 6.50% [8],[10],[42] 6.50% [8],[10],[42]  
Base Rate Floor 1.00% [6],[7],[17],[41] 1.00% [6],[7],[17],[41] 1.00% [6],[7],[17],[41] 1.00% [6],[7],[17],[41] 1.00% [6],[7],[17],[41] 1.00% [6],[7],[17],[41] 1.00% [6],[7],[17],[41] 1.00% [10],[42] 1.00% [10],[42] 1.00% [10],[42] 1.00% [10],[42] 1.00% [10],[42] 1.00% [10],[42] 1.00% [10],[42]  
Principal amount $ 28,500,000 [7],[13],[17],[41]             $ 28,500,000 [10],[14],[42]              
Amortized Cost 27,900,000 [7],[17],[41]             28,000,000.0 [10],[42]              
Fair Value $ (27,700,000) [4],[7],[17],[41]             $ (27,400,000) [1],[10],[42]              
Investment, Identifier [Axis]: Rise Baking Company, Food, Beverage & Tobacco 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 30,300,000             $ 30,400,000              
Amortized Cost 29,800,000             29,800,000              
Fair Value $ (29,500,000)             $ (29,200,000)              
Investment, Identifier [Axis]: Rise Baking Company, Food, Beverage & Tobacco 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 4,600,000 [13],[19]             $ 3,900,000 [14],[18]              
Amortized Cost 4,600,000 [19]             3,900,000 [18]              
Fair Value $ (4,500,000) [4],[19]             $ (3,700,000) [1],[18]              
Investment, Identifier [Axis]: Rise Baking Company, Food, Beverage & Tobacco 3 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 1,700,000             $ 1,400,000              
Amortized Cost 1,700,000             1,400,000              
Fair Value (1,700,000)             (1,400,000)              
Investment, Identifier [Axis]: Roemanu LLC (FKA Toorak Capital Partners LLC), Private Equity                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (254,800,000)             $ (261,200,000)             (199,300,000)
Investment, Identifier [Axis]: Roemanu LLC (FKA Toorak Capital Partners LLC), Private Equity, Financial Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[34] 220,778,388 220,778,388 220,778,388 220,778,388 220,778,388 220,778,388 220,778,388                
Amortized Cost [7],[34] $ 236,500,000                            
Fair Value [7],[34] $ (254,800,000)                            
Investment, Identifier [Axis]: Roemanu LLC (FKA Toorak Capital Partners LLC), Private Equity, Financial Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 40,000,000 40,000,000 40,000,000 40,000,000 40,000,000 40,000,000 40,000,000                
Amortized Cost $ 50,200,000                            
Fair Value $ (46,200,000)                            
Investment, Identifier [Axis]: Roemanu LLC (FKA Toorak Capital Partners LLC), Private Equity, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [11],[14],[35]               220,778,388 220,778,388 220,778,388 220,778,388 220,778,388 220,778,388 220,778,388  
Amortized Cost [11],[35]               $ 236,400,000              
Fair Value [1],[11],[35]               $ (261,200,000)              
Investment, Identifier [Axis]: Roemanu LLC (FKA Toorak Capital Partners LLC), Private Equity, Real Estate | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares               40,000,000 40,000,000 40,000,000 40,000,000 40,000,000 40,000,000 40,000,000  
Amortized Cost               $ 50,200,000              
Fair Value               (47,300,000)              
Investment, Identifier [Axis]: Roemanu LLC (FKA Toorak Capital Partners LLC), Structured Mezzanine                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ 0             (22,000,000.0)
Investment, Identifier [Axis]: SAMBA Safety Inc, Software & Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 27,000,000.0             $ 27,100,000              
Amortized Cost 26,800,000             26,900,000              
Fair Value $ (26,800,000)             $ (26,800,000)              
Investment, Identifier [Axis]: SAMBA Safety Inc, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% [6],[41] 5.25% [6],[41] 5.25% [6],[41] 5.25% [6],[41] 5.25% [6],[41] 5.25% [6],[41] 5.25% [6],[41] 5.25% [8],[42] 5.25% [8],[42] 5.25% [8],[42] 5.25% [8],[42] 5.25% [8],[42] 5.25% [8],[42] 5.25% [8],[42]  
Base Rate Floor 1.00% [6],[41] 1.00% [6],[41] 1.00% [6],[41] 1.00% [6],[41] 1.00% [6],[41] 1.00% [6],[41] 1.00% [6],[41] 1.00% [42] 1.00% [42] 1.00% [42] 1.00% [42] 1.00% [42] 1.00% [42] 1.00% [42]  
Principal amount $ 6,000,000.0 [13],[41]             $ 6,100,000 [14],[42]              
Amortized Cost 6,000,000.0 [41]             6,000,000.0 [42]              
Fair Value $ (6,000,000.0) [4],[41]             $ (6,000,000.0) [1],[42]              
Investment, Identifier [Axis]: SAMBA Safety Inc, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 600,000 [7],[13]             $ 2,400,000 [14],[18]              
Amortized Cost 600,000 [7]             2,400,000 [18]              
Fair Value $ (600,000) [4],[7]             $ (2,400,000) [1],[18]              
Investment, Identifier [Axis]: SAMBA Safety Inc, Software & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19] 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%                
Base Rate Floor [6],[19] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[19] $ 1,800,000                            
Amortized Cost [19] 1,800,000                            
Fair Value [4],[19] $ (1,800,000)                            
Investment, Identifier [Axis]: SG Residential Mortgage Trust 2022-2, Structured Mezzanine, Real Estate | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate               5.40% 5.40% 5.40% 5.40% 5.40% 5.40% 5.40%  
Principal amount               $ 4,600,000              
Amortized Cost               3,800,000              
Fair Value               $ (3,700,000)              
Investment, Identifier [Axis]: SG Residential Mortgage Trust 2022-2, Structured Mezzanine, Real Estate Management & Development | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate 5.40% 5.40% 5.40% 5.40% 5.40% 5.40% 5.40%                
Principal amount $ 4,600,000                            
Amortized Cost 3,800,000                            
Fair Value $ (3,900,000)                            
Investment, Identifier [Axis]: SI Group Inc, Materials | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 4.75% 4.75% 4.75% 4.75% 4.75% 4.75% 4.75% 4.75% 4.75% 4.75% 4.75% 4.75% 4.75% 4.75%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount $ 1,500,000             $ 1,500,000              
Amortized Cost 1,500,000             1,500,000              
Fair Value $ (1,300,000)             $ (1,200,000)              
Investment, Identifier [Axis]: SIRVA Worldwide Inc, Commercial & Professional Services 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount $ 6,800,000             $ 6,900,000              
Amortized Cost 6,600,000             6,600,000              
Fair Value $ (6,300,000)             $ (6,100,000)              
Investment, Identifier [Axis]: SIRVA Worldwide Inc, Commercial & Professional Services 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 9.50% 9.50% 9.50% 9.50% 9.50% 9.50% 9.50% 9.50% 9.50% 9.50% 9.50% 9.50% 9.50% 9.50%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount $ 10,300,000             $ 10,300,000              
Amortized Cost 8,800,000             8,700,000              
Fair Value $ (8,900,000)             $ (8,900,000)              
Investment, Identifier [Axis]: Safe-Guard Products International LLC, Diversified Financials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[22]               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Base Rate Floor [22]               0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount [14],[22]               $ 100,000              
Amortized Cost [22]               100,000              
Fair Value [1],[22]               $ (100,000)              
Investment, Identifier [Axis]: Safe-Guard Products International LLC, Diversified Financials | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Base Rate Floor               0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount               $ 71,700,000              
Amortized Cost               72,100,000              
Fair Value               $ (71,700,000)              
Investment, Identifier [Axis]: Safe-Guard Products International LLC, Financial Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[20] 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%                
Base Rate Floor [6],[20] 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount [13],[20] $ 100,000                            
Amortized Cost [20] 100,000                            
Fair Value [4],[20] $ (100,000)                            
Investment, Identifier [Axis]: Safe-Guard Products International LLC, Financial Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%                
Base Rate Floor 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount $ 71,700,000                            
Amortized Cost 72,100,000                            
Fair Value $ (71,700,000)                            
Investment, Identifier [Axis]: Saluda Grade Alternative Mortgage Trust 2022-BC2, Structured Mezzanine, Real Estate 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate [11],[28]               8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%  
Principal amount [11],[14],[28]               $ 5,700,000              
Amortized Cost [11],[28]               5,700,000              
Fair Value [1],[11],[28]               $ (5,700,000)              
Investment, Identifier [Axis]: Saluda Grade Alternative Mortgage Trust 2022-BC2, Structured Mezzanine, Real Estate 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate [11],[28]               18.00% 18.00% 18.00% 18.00% 18.00% 18.00% 18.00%  
Principal amount [11],[14],[28]               $ 3,400,000              
Amortized Cost [11],[28]               2,300,000              
Fair Value [1],[11],[28]               $ (2,400,000)              
Investment, Identifier [Axis]: Saluda Grade Alternative Mortgage Trust 2022-BC2, Structured Mezzanine, Real Estate Management & Development                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate [7],[33] 18.00% 18.00% 18.00% 18.00% 18.00% 18.00% 18.00%                
Principal amount [7],[33] $ 3,400,000                            
Amortized Cost [7],[33] 2,300,000                            
Fair Value [7],[33] $ (2,300,000)                            
Investment, Identifier [Axis]: Saluda Grade Alternative Mortgage Trust 2022-BC2, Structured Mezzanine, Real Estate Management & Development | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%                
Principal amount $ 5,700,000                            
Amortized Cost 5,700,000                            
Fair Value $ (5,700,000)                            
Investment, Identifier [Axis]: Saluda Grade Alternative Mortgage Trust 2022-BC2, Term Loan, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate [11],[28]               7.30% 7.30% 7.30% 7.30% 7.30% 7.30% 7.30%  
Principal amount [11],[14],[28]               $ 10,500,000              
Amortized Cost [11],[28]               10,500,000              
Fair Value [1],[11],[28]               $ (10,300,000)              
Investment, Identifier [Axis]: Saluda Grade Alternative Mortgage Trust 2022-BC2, Term Loan, Real Estate | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate               7.30% 7.30% 7.30% 7.30% 7.30% 7.30% 7.30%  
Principal amount               $ 24,000,000.0              
Amortized Cost               23,700,000              
Fair Value               $ (23,700,000)              
Investment, Identifier [Axis]: Saluda Grade Alternative Mortgage Trust 2022-BC2, Term Loan, Real Estate Management & Development | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate 7.30% 7.30% 7.30% 7.30% 7.30% 7.30% 7.30%                
Principal amount $ 34,500,000                            
Amortized Cost 34,100,000                            
Fair Value $ (34,100,000)                            
Investment, Identifier [Axis]: Saturn Oil & Gas Inc, Common Stock, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[32],[33],[39],[53],[55] 355,993 355,993 355,993 355,993 355,993 355,993 355,993                
Amortized Cost [7],[32],[33],[39],[53],[55] $ 700,000                            
Fair Value [7],[32],[33],[39],[53],[55] $ (700,000)                            
Investment, Identifier [Axis]: SavATree LLC, Consumer Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 39,500,000             $ 39,600,000              
Amortized Cost 39,200,000             39,200,000              
Fair Value $ (38,700,000)             $ (38,900,000)              
Investment, Identifier [Axis]: SavATree LLC, Consumer Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [6],[7] 5.25% [8],[11] 5.25% [8],[11] 5.25% [8],[11] 5.25% [8],[11] 5.25% [8],[11] 5.25% [8],[11] 5.25% [8],[11]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 6,100,000 [7],[13]             $ 5,500,000 [11],[14]              
Amortized Cost 6,000,000.0 [7]             5,500,000 [11]              
Fair Value $ (6,000,000.0) [4],[7]             $ (5,400,000) [1],[11]              
Investment, Identifier [Axis]: SavATree LLC, Consumer Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% [6],[19] 5.25% [6],[19] 5.25% [6],[19] 5.25% [6],[19] 5.25% [6],[19] 5.25% [6],[19] 5.25% [6],[19] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 3,400,000 [13],[19]             $ 4,000,000.0 [14],[18]              
Amortized Cost 3,400,000 [19]             4,000,000.0 [18]              
Fair Value $ (3,300,000) [4],[19]             $ (3,900,000) [1],[18]              
Investment, Identifier [Axis]: SavATree LLC, Consumer Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.25% [6],[19] 5.25% [6],[19] 5.25% [6],[19] 5.25% [6],[19] 5.25% [6],[19] 5.25% [6],[19] 5.25% [6],[19] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18] 5.25% [8],[18]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 6,300,000 [13],[19]             $ 6,300,000 [14],[18]              
Amortized Cost 6,300,000 [19]             6,300,000 [18]              
Fair Value $ (6,200,000) [4],[19]             $ (6,200,000) [1],[18]              
Investment, Identifier [Axis]: Sealane Trade Finance, Banks | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 1,104,510 1,104,510 1,104,510 1,104,510 1,104,510 1,104,510 1,104,510 1,104,510 1,104,510 1,104,510 1,104,510 1,104,510 1,104,510 1,104,510  
Amortized Cost $ 1,100,000             $ 1,100,000              
Fair Value $ (200,000)             $ (200,000)              
Investment, Identifier [Axis]: Sequel Youth & Family Services LLC, Class R Common Stock, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 900,000 [32],[51] 900,000 [32],[51] 900,000 [32],[51] 900,000 [32],[51] 900,000 [32],[51] 900,000 [32],[51] 900,000 [32],[51] 900,000 [27],[52] 900,000 [27],[52] 900,000 [27],[52] 900,000 [27],[52] 900,000 [27],[52] 900,000 [27],[52] 900,000 [27],[52]  
Amortized Cost $ 0 [32],[51]             $ 0 [27],[52]              
Fair Value $ 0 [32],[51]             $ 0 [1],[27],[52]              
Investment, Identifier [Axis]: Sequel Youth & Family Services LLC, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate 3.00% [6],[7],[29],[32] 3.00% [6],[7],[29],[32] 3.00% [6],[7],[29],[32] 3.00% [6],[7],[29],[32] 3.00% [6],[7],[29],[32] 3.00% [6],[7],[29],[32] 3.00% [6],[7],[29],[32] 3.00% [8],[11],[24],[27] 3.00% [8],[11],[24],[27] 3.00% [8],[11],[24],[27] 3.00% [8],[11],[24],[27] 3.00% [8],[11],[24],[27] 3.00% [8],[11],[24],[27] 3.00% [8],[11],[24],[27]  
Principal amount $ 57,200,000 [7],[13],[29],[32]             $ 57,200,000 [11],[14],[24],[27]              
Amortized Cost 8,900,000 [7],[29],[32]             8,900,000 [11],[24],[27]              
Fair Value $ (300,000) [4],[7],[29],[32]             $ (300,000) [1],[11],[24],[27]              
Investment, Identifier [Axis]: SitusAMC Holdings Corp, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[9],[10],[23]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base Rate Floor [9],[10],[23]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [9],[10],[14],[23]               $ 55,200,000              
Amortized Cost [9],[10],[23]               54,700,000              
Fair Value [1],[9],[10],[23]               $ (53,200,000)              
Investment, Identifier [Axis]: SitusAMC Holdings Corp, Real Estate | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base Rate Floor               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount               $ 39,500,000              
Amortized Cost               38,700,000              
Fair Value               $ (38,100,000)              
Investment, Identifier [Axis]: SitusAMC Holdings Corp, Real Estate Management & Development                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[16],[17],[21] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base Rate Floor [6],[16],[17],[21] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[16],[17],[21] $ 55,000,000.0                            
Amortized Cost [16],[17],[21] 54,600,000                            
Fair Value [4],[16],[17],[21] $ (53,600,000)                            
Investment, Identifier [Axis]: SitusAMC Holdings Corp, Real Estate Management & Development | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount $ 39,400,000                            
Amortized Cost 38,600,000                            
Fair Value $ (38,400,000)                            
Investment, Identifier [Axis]: Solera LLC, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 8.00% [6],[7],[43] 8.00% [6],[7],[43] 8.00% [6],[7],[43] 8.00% [6],[7],[43] 8.00% [6],[7],[43] 8.00% [6],[7],[43] 8.00% [6],[7],[43] 8.00% [8],[11],[40] 8.00% [8],[11],[40] 8.00% [8],[11],[40] 8.00% [8],[11],[40] 8.00% [8],[11],[40] 8.00% [8],[11],[40] 8.00% [8],[11],[40]  
Base Rate Floor 1.00% [6],[7],[43] 1.00% [6],[7],[43] 1.00% [6],[7],[43] 1.00% [6],[7],[43] 1.00% [6],[7],[43] 1.00% [6],[7],[43] 1.00% [6],[7],[43] 1.00% [11],[40] 1.00% [11],[40] 1.00% [11],[40] 1.00% [11],[40] 1.00% [11],[40] 1.00% [11],[40] 1.00% [11],[40]  
Principal amount $ 312,400,000 [7],[13],[43]             $ 312,400,000 [11],[14],[40]              
Amortized Cost 297,600,000 [7],[43]             297,300,000 [11],[40]              
Fair Value $ (303,000,000.0) [4],[7],[43]             $ (307,700,000) [1],[11],[40]              
Investment, Identifier [Axis]: Solina France SASU, Food, Beverage & Tobacco                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[7],[33],[41] 6.50% [6],[7],[33],[41] 6.50% [6],[7],[33],[41] 6.50% [6],[7],[33],[41] 6.50% [6],[7],[33],[41] 6.50% [6],[7],[33],[41] 6.50% [6],[7],[33],[41] 6.50% [8],[11],[28],[42] 6.50% [8],[11],[28],[42] 6.50% [8],[11],[28],[42] 6.50% [8],[11],[28],[42] 6.50% [8],[11],[28],[42] 6.50% [8],[11],[28],[42] 6.50% [8],[11],[28],[42]  
Base Rate Floor 0.00% [6],[7],[33],[41] 0.00% [6],[7],[33],[41] 0.00% [6],[7],[33],[41] 0.00% [6],[7],[33],[41] 0.00% [6],[7],[33],[41] 0.00% [6],[7],[33],[41] 0.00% [6],[7],[33],[41] 0.00% [11],[28],[42] 0.00% [11],[28],[42] 0.00% [11],[28],[42] 0.00% [11],[28],[42] 0.00% [11],[28],[42] 0.00% [11],[28],[42] 0.00% [11],[28],[42]  
Principal amount $ 19,500,000 [7],[13],[33],[41]             $ 40,000,000.0 [11],[14],[28],[42]              
Amortized Cost 18,900,000 [7],[33],[41]             38,800,000 [11],[28],[42]              
Fair Value $ (19,400,000) [4],[7],[33],[41]             (39,100,000) [1],[11],[28],[42]              
Investment, Identifier [Axis]: Solina France SASU, Food, Beverage & Tobacco | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount $ 20,500,000                            
Amortized Cost 20,300,000                            
Fair Value $ (20,400,000)                            
Investment, Identifier [Axis]: Sorenson Communications LLC, 0.13                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [11],[14],[27],[54],[56]               9,900,000              
Amortized Cost [11],[27],[54],[56]               8,900,000              
Fair Value [1],[11],[27],[54],[56]               (9,300,000)              
Investment, Identifier [Axis]: Sorenson Communications LLC, Common Stock, Equity/Other                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value [5]               $ 0             (67,500,000)
Investment, Identifier [Axis]: Sorenson Communications LLC, Common Stock, Telecommunication Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [7],[32],[53] 42,731 [55] 42,731 [55] 42,731 [55] 42,731 [55] 42,731 [55] 42,731 [55] 42,731 [55] 42,731 [17] 42,731 [17] 42,731 [17] 42,731 [17] 42,731 [17] 42,731 [17] 42,731 [17]  
Amortized Cost [7],[32],[53] $ 7,100,000 [55]             $ 7,100,000 [17]              
Fair Value [7],[32],[53] $ 0 [55]             0 [1],[17]              
Investment, Identifier [Axis]: Sorenson Communications LLC, Senior Secured Loans—First Lien                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value [5]               $ 0             (60,100,000)
Investment, Identifier [Axis]: Sorenson Communications LLC, Telecommunication Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount $ 19,300,000             $ 20,000,000.0              
Amortized Cost 18,700,000             19,300,000              
Fair Value $ (18,400,000)             $ (19,100,000)              
Investment, Identifier [Axis]: Sorenson Communications LLC, Telecommunication Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[16],[20],[21],[39] 5.50% [6],[16],[20],[21],[39] 5.50% [6],[16],[20],[21],[39] 5.50% [6],[16],[20],[21],[39] 5.50% [6],[16],[20],[21],[39] 5.50% [6],[16],[20],[21],[39] 5.50% [6],[16],[20],[21],[39] 5.50% [8],[9],[22],[23],[40] 5.50% [8],[9],[22],[23],[40] 5.50% [8],[9],[22],[23],[40] 5.50% [8],[9],[22],[23],[40] 5.50% [8],[9],[22],[23],[40] 5.50% [8],[9],[22],[23],[40] 5.50% [8],[9],[22],[23],[40]  
Base Rate Floor 0.80% [6],[16],[20],[21],[39] 0.80% [6],[16],[20],[21],[39] 0.80% [6],[16],[20],[21],[39] 0.80% [6],[16],[20],[21],[39] 0.80% [6],[16],[20],[21],[39] 0.80% [6],[16],[20],[21],[39] 0.80% [6],[16],[20],[21],[39] 0.80% [9],[22],[23],[40] 0.80% [9],[22],[23],[40] 0.80% [9],[22],[23],[40] 0.80% [9],[22],[23],[40] 0.80% [9],[22],[23],[40] 0.80% [9],[22],[23],[40] 0.80% [9],[22],[23],[40]  
Principal amount $ 32,500,000 [13],[16],[20],[21],[39]             $ 33,600,000 [9],[14],[22],[23],[40]              
Amortized Cost 30,900,000 [16],[20],[21],[39]             31,900,000 [9],[22],[23],[40]              
Fair Value (31,000,000.0) [4],[16],[20],[21],[39]             (32,200,000) [1],[9],[22],[23],[40]              
Investment, Identifier [Axis]: Sorenson Communications LLC, Telecommunication Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount 9,900,000 [7],[32],[53],[55]             40,300,000 [11],[14],[27],[54],[56]              
Amortized Cost 8,900,000 [7],[32],[53],[55]             32,000,000.0 [11],[27],[54],[56]              
Fair Value (9,100,000) [7],[32],[53],[55]             (34,100,000) [1],[11],[27],[54],[56]              
Investment, Identifier [Axis]: Sorenson Communications LLC, Telecommunication Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [7],[32],[53],[55] 40,300,000                            
Amortized Cost [7],[32],[53],[55] 32,000,000.0                            
Fair Value [7],[32],[53],[55] $ (33,000,000.0)                            
Investment, Identifier [Axis]: Sound United LLC, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ 0             (77,500,000)
Investment, Identifier [Axis]: Sound United LLC, Common Stock, Consumer Durables & Apparel                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [11],[27]               532,768 532,768 532,768 532,768 532,768 532,768 532,768  
Amortized Cost [11],[27]               $ 700,000              
Fair Value [1],[11],[27]               $ (7,000,000.0)              
Investment, Identifier [Axis]: Source Code LLC, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[16],[17],[21] 6.50% [6],[16],[17],[21] 6.50% [6],[16],[17],[21] 6.50% [6],[16],[17],[21] 6.50% [6],[16],[17],[21] 6.50% [6],[16],[17],[21] 6.50% [6],[16],[17],[21] 6.50% [8],[9],[10],[23] 6.50% [8],[9],[10],[23] 6.50% [8],[9],[10],[23] 6.50% [8],[9],[10],[23] 6.50% [8],[9],[10],[23] 6.50% [8],[9],[10],[23] 6.50% [8],[9],[10],[23]  
Base Rate Floor 1.00% [6],[16],[17],[21] 1.00% [6],[16],[17],[21] 1.00% [6],[16],[17],[21] 1.00% [6],[16],[17],[21] 1.00% [6],[16],[17],[21] 1.00% [6],[16],[17],[21] 1.00% [6],[16],[17],[21] 1.00% [9],[10],[23] 1.00% [9],[10],[23] 1.00% [9],[10],[23] 1.00% [9],[10],[23] 1.00% [9],[10],[23] 1.00% [9],[10],[23] 1.00% [9],[10],[23]  
Principal amount $ 52,600,000 [13],[16],[17],[21]             $ 52,800,000 [9],[10],[14],[23]              
Amortized Cost 51,800,000 [16],[17],[21]             51,900,000 [9],[10],[23]              
Fair Value $ (51,600,000) [4],[16],[17],[21]             $ (51,300,000) [1],[9],[10],[23]              
Investment, Identifier [Axis]: Source Code LLC, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 15,300,000 [13],[19]             $ 15,300,000 [14],[18]              
Amortized Cost 15,000,000.0 [19]             15,000,000.0 [18]              
Fair Value $ (15,000,000.0) [4],[19]             $ (14,800,000) [1],[18]              
Investment, Identifier [Axis]: Spins LLC, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[7],[21],[36],[41] 5.50% [6],[7],[21],[36],[41] 5.50% [6],[7],[21],[36],[41] 5.50% [6],[7],[21],[36],[41] 5.50% [6],[7],[21],[36],[41] 5.50% [6],[7],[21],[36],[41] 5.50% [6],[7],[21],[36],[41] 5.50% [8],[11],[23],[37],[42] 5.50% [8],[11],[23],[37],[42] 5.50% [8],[11],[23],[37],[42] 5.50% [8],[11],[23],[37],[42] 5.50% [8],[11],[23],[37],[42] 5.50% [8],[11],[23],[37],[42] 5.50% [8],[11],[23],[37],[42]  
Base Rate Floor 1.00% [6],[7],[21],[36],[41] 1.00% [6],[7],[21],[36],[41] 1.00% [6],[7],[21],[36],[41] 1.00% [6],[7],[21],[36],[41] 1.00% [6],[7],[21],[36],[41] 1.00% [6],[7],[21],[36],[41] 1.00% [6],[7],[21],[36],[41] 1.00% [11],[23],[37],[42] 1.00% [11],[23],[37],[42] 1.00% [11],[23],[37],[42] 1.00% [11],[23],[37],[42] 1.00% [11],[23],[37],[42] 1.00% [11],[23],[37],[42] 1.00% [11],[23],[37],[42]  
Principal amount $ 68,000,000.0 [7],[13],[21],[36],[41]             $ 68,200,000 [11],[14],[23],[37],[42]              
Amortized Cost 65,300,000 [7],[21],[36],[41]             65,400,000 [11],[23],[37],[42]              
Fair Value $ (68,000,000.0) [4],[7],[21],[36],[41]             $ (68,200,000) [1],[11],[23],[37],[42]              
Investment, Identifier [Axis]: Spins LLC, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 7,900,000 [13],[19]             $ 16,500,000 [14],[18]              
Amortized Cost 7,900,000 [19]             16,500,000 [18]              
Fair Value $ (7,900,000) [4],[19]             $ (16,500,000) [1],[18]              
Investment, Identifier [Axis]: Spins LLC, Software & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [6],[19] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18] 5.50% [8],[18]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 16,500,000 [13],[19]             $ 7,900,000 [14],[18]              
Amortized Cost 16,500,000 [19]             7,900,000 [18]              
Fair Value $ (16,500,000) [4],[19]             $ (7,900,000) [1],[18]              
Investment, Identifier [Axis]: Spotless Brands LLC, Consumer Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base Rate Floor [6],[7] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [7],[13] $ 12,400,000                            
Amortized Cost [7] 12,200,000                            
Fair Value [4],[7] $ (12,100,000)                            
Investment, Identifier [Axis]: Spotless Brands LLC, Consumer Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19] 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%                
Base Rate Floor [6],[19] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[19] $ 18,700,000                            
Amortized Cost [19] 18,400,000                            
Fair Value [4],[19] $ (18,400,000)                            
Investment, Identifier [Axis]: Staples Canada, Consumer Discretionary Distribution & Retail                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[33] 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%                
Base Rate Floor [6],[7],[33] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [7],[13],[33]             $ 29.2                
Amortized Cost [7],[33] $ 22,800,000                            
Fair Value [4],[7],[33] $ (22,000,000.0)                            
Investment, Identifier [Axis]: Staples Canada, Consumer Discretionary Distribution & Retail | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%                
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount             $ 71.0                
Amortized Cost $ 54,500,000                            
Fair Value $ (53,500,000)                            
Investment, Identifier [Axis]: Staples Canada, Retailing                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11],[28]               7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%  
Base Rate Floor [11],[28]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [11],[14],[28]                           $ 30.5  
Amortized Cost [11],[28]               $ 23,900,000              
Fair Value [1],[11],[28]               $ (22,900,000)              
Investment, Identifier [Axis]: Staples Canada, Retailing | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate               7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%  
Base Rate Floor               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount                           $ 74.2  
Amortized Cost               $ 57,000,000.0              
Fair Value               $ (55,600,000)              
Investment, Identifier [Axis]: Star Mountain Diversified Credit Income Fund III, LP, Private Equity, Diversified Financials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [14],[28],[57]               23,500,000 23,500,000 23,500,000 23,500,000 23,500,000 23,500,000 23,500,000  
Amortized Cost [28],[57]               $ 23,500,000              
Fair Value [1],[28],[57]               $ (23,800,000)              
Investment, Identifier [Axis]: Star Mountain Diversified Credit Income Fund III, LP, Private Equity, Financial Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [33],[58] 23,500,000 23,500,000 23,500,000 23,500,000 23,500,000 23,500,000 23,500,000                
Amortized Cost [33],[58] $ 23,500,000                            
Fair Value [33],[58] $ (23,600,000)                            
Investment, Identifier [Axis]: Star Mountain Strategic Credit Income Fund IV LP, Private Equity, Diversified Financials | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares               42,500,000 42,500,000 42,500,000 42,500,000 42,500,000 42,500,000 42,500,000  
Amortized Cost               $ 42,500,000              
Fair Value               $ (44,000,000.0)              
Investment, Identifier [Axis]: Star Mountain Strategic Credit Income Fund IV LP, Private Equity, Financial Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 42,500,000 42,500,000 42,500,000 42,500,000 42,500,000 42,500,000 42,500,000                
Amortized Cost $ 42,500,000                            
Fair Value $ (43,300,000)                            
Investment, Identifier [Axis]: Stuart Weitzman Inc, Common Stock, Consumer Durables & Apparel                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 5,451 [7],[32] 5,451 [7],[32] 5,451 [7],[32] 5,451 [7],[32] 5,451 [7],[32] 5,451 [7],[32] 5,451 [7],[32] 5,451 [11],[27] 5,451 [11],[27] 5,451 [11],[27] 5,451 [11],[27] 5,451 [11],[27] 5,451 [11],[27] 5,451 [11],[27]  
Amortized Cost $ 0 [7],[32]             $ 0 [11],[27]              
Fair Value $ 0 [7],[32]             $ 0 [1],[11],[27]              
Investment, Identifier [Axis]: Summit Interconnect Inc, Capital Goods | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 19,500,000             $ 19,500,000              
Amortized Cost 19,200,000             19,300,000              
Fair Value $ (18,400,000)             $ (18,400,000)              
Investment, Identifier [Axis]: Summit Interconnect Inc, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[7],[16],[17],[20],[21],[41] 6.00% [6],[7],[16],[17],[20],[21],[41] 6.00% [6],[7],[16],[17],[20],[21],[41] 6.00% [6],[7],[16],[17],[20],[21],[41] 6.00% [6],[7],[16],[17],[20],[21],[41] 6.00% [6],[7],[16],[17],[20],[21],[41] 6.00% [6],[7],[16],[17],[20],[21],[41] 6.00% [8],[9],[10],[11],[22],[23],[42] 6.00% [8],[9],[10],[11],[22],[23],[42] 6.00% [8],[9],[10],[11],[22],[23],[42] 6.00% [8],[9],[10],[11],[22],[23],[42] 6.00% [8],[9],[10],[11],[22],[23],[42] 6.00% [8],[9],[10],[11],[22],[23],[42] 6.00% [8],[9],[10],[11],[22],[23],[42]  
Base Rate Floor 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42] 1.00% [9],[10],[11],[22],[23],[42]  
Principal amount $ 136,200,000 [7],[13],[16],[17],[20],[21],[41]             $ 136,500,000 [9],[10],[11],[14],[22],[23],[42]              
Amortized Cost 135,200,000 [7],[16],[17],[20],[21],[41]             135,400,000 [9],[10],[11],[22],[23],[42]              
Fair Value $ (128,600,000) [4],[7],[16],[17],[20],[21],[41]             $ (128,700,000) [1],[9],[10],[11],[22],[23],[42]              
Investment, Identifier [Axis]: Summit Interconnect Inc, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 9,400,000 [13],[19]             $ 9,400,000 [14],[18]              
Amortized Cost 9,400,000 [19]             9,400,000 [18]              
Fair Value (8,900,000) [4],[19]             (8,900,000) [1],[18]              
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value 0             (500,000)              
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc 1, Senior Secured Loans—First Lien                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value [60]               (500,000)             (6,000,000.0)
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value 0             (2,000,000.0)              
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc 2, Senior Secured Loans—First Lien                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value [60]               (2,000,000.0)             0
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ 0             $ 0              
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 3.75% [6],[7],[29],[32] 3.75% [6],[7],[29],[32] 3.75% [6],[7],[29],[32] 3.75% [6],[7],[29],[32] 3.75% [6],[7],[29],[32] 3.75% [6],[7],[29],[32] 3.75% [6],[7],[29],[32] 1.00% [8],[11],[44] 1.00% [8],[11],[44] 1.00% [8],[11],[44] 1.00% [8],[11],[44] 1.00% [8],[11],[44] 1.00% [8],[11],[44] 1.00% [8],[11],[44]  
Rate, PIK 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 8.50% [8],[11],[44] 8.50% [8],[11],[44] 8.50% [8],[11],[44] 8.50% [8],[11],[44] 8.50% [8],[11],[44] 8.50% [8],[11],[44] 8.50% [8],[11],[44]  
Rate, Max PIK 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 8.50% [8],[11],[44] 8.50% [8],[11],[44] 8.50% [8],[11],[44] 8.50% [8],[11],[44] 8.50% [8],[11],[44] 8.50% [8],[11],[44] 8.50% [8],[11],[44]  
Base Rate Floor 1.00% [6],[7],[29],[32] 1.00% [6],[7],[29],[32] 1.00% [6],[7],[29],[32] 1.00% [6],[7],[29],[32] 1.00% [6],[7],[29],[32] 1.00% [6],[7],[29],[32] 1.00% [6],[7],[29],[32] 0.00% [11],[44] 0.00% [11],[44] 0.00% [11],[44] 0.00% [11],[44] 0.00% [11],[44] 0.00% [11],[44] 0.00% [11],[44]  
Principal amount $ 4,000,000.0 [7],[13],[29],[32]             $ 2,000,000.0 [11],[14],[44]              
Amortized Cost 3,700,000 [7],[29],[32]             2,000,000.0 [11],[44]              
Fair Value $ (300,000) [4],[7],[29],[32]             $ (2,000,000.0) [1],[11],[44]              
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 3.75% [6],[7],[29],[32] 3.75% [6],[7],[29],[32] 3.75% [6],[7],[29],[32] 3.75% [6],[7],[29],[32] 3.75% [6],[7],[29],[32] 3.75% [6],[7],[29],[32] 3.75% [6],[7],[29],[32] 3.75% [8],[11],[24],[27],[44] 3.75% [8],[11],[24],[27],[44] 3.75% [8],[11],[24],[27],[44] 3.75% [8],[11],[24],[27],[44] 3.75% [8],[11],[24],[27],[44] 3.75% [8],[11],[24],[27],[44] 3.75% [8],[11],[24],[27],[44]  
Rate, PIK 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 3.80% [8],[11],[24],[27],[44] 3.80% [8],[11],[24],[27],[44] 3.80% [8],[11],[24],[27],[44] 3.80% [8],[11],[24],[27],[44] 3.80% [8],[11],[24],[27],[44] 3.80% [8],[11],[24],[27],[44] 3.80% [8],[11],[24],[27],[44]  
Rate, Max PIK 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 3.80% [6],[7],[29],[32] 3.80% [8],[11],[24],[27],[44] 3.80% [8],[11],[24],[27],[44] 3.80% [8],[11],[24],[27],[44] 3.80% [8],[11],[24],[27],[44] 3.80% [8],[11],[24],[27],[44] 3.80% [8],[11],[24],[27],[44] 3.80% [8],[11],[24],[27],[44]  
Base Rate Floor 1.00% [6],[7],[29],[32] 1.00% [6],[7],[29],[32] 1.00% [6],[7],[29],[32] 1.00% [6],[7],[29],[32] 1.00% [6],[7],[29],[32] 1.00% [6],[7],[29],[32] 1.00% [6],[7],[29],[32] 1.00% [11],[24],[27],[44] 1.00% [11],[24],[27],[44] 1.00% [11],[24],[27],[44] 1.00% [11],[24],[27],[44] 1.00% [11],[24],[27],[44] 1.00% [11],[24],[27],[44] 1.00% [11],[24],[27],[44]  
Principal amount $ 2,100,000 [7],[13],[29],[32]             $ 6,100,000 [11],[14],[24],[27],[44]              
Amortized Cost 2,000,000.0 [7],[29],[32]             5,800,000 [11],[24],[27],[44]              
Fair Value $ 0 [4],[7],[29],[32]             $ (500,000) [1],[11],[24],[27],[44]              
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc, Software & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[18],[44]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Rate, PIK [8],[18],[44]               8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%  
Rate, Max PIK [8],[18],[44]               8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%  
Base Rate Floor [18],[44]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount [14],[18],[44]               $ 1,200,000              
Amortized Cost [18],[44]               1,200,000              
Fair Value [1],[18],[44]               $ (1,200,000)              
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc, Software & Services 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11],[24],[27],[44]               4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00%  
Rate, PIK [8],[11],[24],[27],[44]               2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80%  
Rate, Max PIK [8],[11],[24],[27],[44]               2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80%  
Base Rate Floor [11],[24],[27],[44]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [11],[14],[24],[27],[44]               $ 15,100,000              
Amortized Cost [11],[24],[27],[44]               13,500,000              
Fair Value [1],[11],[24],[27],[44]               0              
Investment, Identifier [Axis]: Sungard Availbaility Services Capital Inc, Common Stock, Equity/Other                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value [5]               $ 0             0
Investment, Identifier [Axis]: Sweeping Corp of America Inc, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[7],[41] 5.75% [6],[7],[41] 5.75% [6],[7],[41] 5.75% [6],[7],[41] 5.75% [6],[7],[41] 5.75% [6],[7],[41] 5.75% [6],[7],[41] 5.75% [8],[11],[42] 5.75% [8],[11],[42] 5.75% [8],[11],[42] 5.75% [8],[11],[42] 5.75% [8],[11],[42] 5.75% [8],[11],[42] 5.75% [8],[11],[42]  
Base Rate Floor 1.00% [6],[7],[41] 1.00% [6],[7],[41] 1.00% [6],[7],[41] 1.00% [6],[7],[41] 1.00% [6],[7],[41] 1.00% [6],[7],[41] 1.00% [6],[7],[41] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42] 1.00% [11],[42]  
Principal amount $ 72,000,000.0 [7],[13],[41]             $ 72,200,000 [11],[14],[42]              
Amortized Cost 70,100,000 [7],[41]             70,200,000 [11],[42]              
Fair Value $ (71,500,000) [4],[7],[41]             $ (72,200,000) [1],[11],[42]              
Investment, Identifier [Axis]: Sweeping Corp of America Inc, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Principal amount $ 3,100,000 [7],[13]             $ 1,000,000.0 [11],[14]              
Amortized Cost 3,000,000.0 [7]             1,000,000.0 [11]              
Fair Value $ (3,000,000.0) [4],[7]             $ (1,000,000.0) [1],[11]              
Investment, Identifier [Axis]: Sweeping Corp of America Inc, Commercial & Professional Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 2,600,000 [13],[19]             $ 4,700,000 [14],[18]              
Amortized Cost 2,600,000 [19]             4,700,000 [18]              
Fair Value $ (2,600,000) [4],[19]             $ (4,700,000) [1],[18]              
Investment, Identifier [Axis]: Swift Worldwide Resources Holdco Ltd, Common Stock, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 1,250,000 [7],[32] 1,250,000 [7],[32] 1,250,000 [7],[32] 1,250,000 [7],[32] 1,250,000 [7],[32] 1,250,000 [7],[32] 1,250,000 [7],[32] 1,250,000 [11],[27] 1,250,000 [11],[27] 1,250,000 [11],[27] 1,250,000 [11],[27] 1,250,000 [11],[27] 1,250,000 [11],[27] 1,250,000 [11],[27]  
Amortized Cost $ 1,200,000 [7],[32]             $ 1,200,000 [11],[27]              
Fair Value $ (1,100,000) [7],[32]             $ (1,000,000.0) [1],[11],[27]              
Investment, Identifier [Axis]: TIBCO Software Inc, Preferred Stock, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 12.00% [7] 12.00% [7] 12.00% [7] 12.00% [7] 12.00% [7] 12.00% [7] 12.00% [7] 12.00% [11] 12.00% [11] 12.00% [11] 12.00% [11] 12.00% [11] 12.00% [11] 12.00% [11]  
Rate, Max PIK 12.00% [7] 12.00% [7] 12.00% [7] 12.00% [7] 12.00% [7] 12.00% [7] 12.00% [7] 12.00% [11] 12.00% [11] 12.00% [11] 12.00% [11] 12.00% [11] 12.00% [11] 12.00% [11]  
Base Rate Floor 0.50% [7] 0.50% [7] 0.50% [7] 0.50% [7] 0.50% [7] 0.50% [7] 0.50% [7] 0.50% [11] 0.50% [11] 0.50% [11] 0.50% [11] 0.50% [11] 0.50% [11] 0.50% [11]  
Number of Shares | shares 133,186,150 [7] 133,186,150 [7] 133,186,150 [7] 133,186,150 [7] 133,186,150 [7] 133,186,150 [7] 133,186,150 [7] 133,186,150 [11] 133,186,150 [11] 133,186,150 [11] 133,186,150 [11] 133,186,150 [11] 133,186,150 [11] 133,186,150 [11]  
Amortized Cost $ 127,400,000 [7]             $ 127,300,000 [11]              
Fair Value $ (129,800,000) [7]             $ (129,600,000) [1],[11]              
Investment, Identifier [Axis]: TIBCO Software Inc, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 4.50% [6],[7],[39] 4.50% [6],[7],[39] 4.50% [6],[7],[39] 4.50% [6],[7],[39] 4.50% [6],[7],[39] 4.50% [6],[7],[39] 4.50% [6],[7],[39] 4.50% [8],[11],[40] 4.50% [8],[11],[40] 4.50% [8],[11],[40] 4.50% [8],[11],[40] 4.50% [8],[11],[40] 4.50% [8],[11],[40] 4.50% [8],[11],[40]  
Base Rate Floor 0.50% [6],[7],[39] 0.50% [6],[7],[39] 0.50% [6],[7],[39] 0.50% [6],[7],[39] 0.50% [6],[7],[39] 0.50% [6],[7],[39] 0.50% [6],[7],[39] 0.50% [11],[40] 0.50% [11],[40] 0.50% [11],[40] 0.50% [11],[40] 0.50% [11],[40] 0.50% [11],[40] 0.50% [11],[40]  
Principal amount $ 39,900,000 [7],[13],[39]             $ 39,900,000 [11],[14],[40]              
Amortized Cost 36,600,000 [7],[39]             36,400,000 [11],[40]              
Fair Value $ (36,400,000) [4],[7],[39]             $ (35,700,000) [1],[11],[40]              
Investment, Identifier [Axis]: TIBCO Software Inc, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [7],[39] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Rate, Stated interest rate [8],[11],[40]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Principal amount $ 1,000,000.0 [7],[39]             $ 1,000,000.0 [11],[14],[40]              
Amortized Cost 800,000 [7],[39]             800,000 [11],[40]              
Fair Value $ (900,000) [7],[39]             $ (800,000) [1],[11],[40]              
Investment, Identifier [Axis]: Tangoe LLC, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[7],[36],[41],[61] 6.50% [6],[7],[36],[41],[61] 6.50% [6],[7],[36],[41],[61] 6.50% [6],[7],[36],[41],[61] 6.50% [6],[7],[36],[41],[61] 6.50% [6],[7],[36],[41],[61] 6.50% [6],[7],[36],[41],[61] 6.50% [8],[11],[37],[42] 6.50% [8],[11],[37],[42] 6.50% [8],[11],[37],[42] 6.50% [8],[11],[37],[42] 6.50% [8],[11],[37],[42] 6.50% [8],[11],[37],[42] 6.50% [8],[11],[37],[42]  
Base Rate Floor 1.00% [6],[7],[36],[41],[61] 1.00% [6],[7],[36],[41],[61] 1.00% [6],[7],[36],[41],[61] 1.00% [6],[7],[36],[41],[61] 1.00% [6],[7],[36],[41],[61] 1.00% [6],[7],[36],[41],[61] 1.00% [6],[7],[36],[41],[61] 1.00% [11],[37],[42] 1.00% [11],[37],[42] 1.00% [11],[37],[42] 1.00% [11],[37],[42] 1.00% [11],[37],[42] 1.00% [11],[37],[42] 1.00% [11],[37],[42]  
Principal amount $ 179,500,000 [7],[13],[36],[41],[61]             $ 179,500,000 [11],[14],[37],[42]              
Amortized Cost 166,200,000 [7],[36],[41],[61]             165,300,000 [11],[37],[42]              
Fair Value $ (148,600,000) [4],[7],[36],[41],[61]             $ (147,200,000) [1],[11],[37],[42]              
Investment, Identifier [Axis]: Tangoe LLC, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 12.50% [6],[7],[36],[41] 12.50% [6],[7],[36],[41] 12.50% [6],[7],[36],[41] 12.50% [6],[7],[36],[41] 12.50% [6],[7],[36],[41] 12.50% [6],[7],[36],[41] 12.50% [6],[7],[36],[41] 12.50% [8],[11],[37],[42] 12.50% [8],[11],[37],[42] 12.50% [8],[11],[37],[42] 12.50% [8],[11],[37],[42] 12.50% [8],[11],[37],[42] 12.50% [8],[11],[37],[42] 12.50% [8],[11],[37],[42]  
Rate, Max PIK 12.50% [6],[7],[36],[41] 12.50% [6],[7],[36],[41] 12.50% [6],[7],[36],[41] 12.50% [6],[7],[36],[41] 12.50% [6],[7],[36],[41] 12.50% [6],[7],[36],[41] 12.50% [6],[7],[36],[41] 12.50% [8],[11],[37],[42] 12.50% [8],[11],[37],[42] 12.50% [8],[11],[37],[42] 12.50% [8],[11],[37],[42] 12.50% [8],[11],[37],[42] 12.50% [8],[11],[37],[42] 12.50% [8],[11],[37],[42]  
Principal amount $ 4,700,000 [7],[13],[36],[41]             $ 3,300,000 [11],[14],[37],[42]              
Amortized Cost 4,700,000 [7],[36],[41]             3,300,000 [11],[37],[42]              
Fair Value $ (3,200,000) [4],[7],[36],[41]             $ (2,600,000) [1],[11],[37],[42]              
Investment, Identifier [Axis]: TeamSystem SpA, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[7],[33] 6.25% [6],[7],[33] 6.25% [6],[7],[33] 6.25% [6],[7],[33] 6.25% [6],[7],[33] 6.25% [6],[7],[33] 6.25% [6],[7],[33] 6.25% [8],[11],[28],[42] 6.25% [8],[11],[28],[42] 6.25% [8],[11],[28],[42] 6.25% [8],[11],[28],[42] 6.25% [8],[11],[28],[42] 6.25% [8],[11],[28],[42] 6.25% [8],[11],[28],[42]  
Base Rate Floor 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28]  
Principal amount | €       € 19.8 [7],[13],[33]             € 19.8 [11],[14],[28]        
Amortized Cost $ 18,900,000 [7],[33]             $ 18,900,000 [11],[28]              
Fair Value (22,100,000) [4],[7],[33]             (21,400,000) [1],[11],[28]              
Investment, Identifier [Axis]: Tekfor HoldCo (formerly Amtek Global Technology Pte Ltd)                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value (4,000,000.0)             (3,900,000)              
Investment, Identifier [Axis]: Tekfor HoldCo (formerly Amtek Global Technology Pte Ltd), Automobiles & Components                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount | €       € 37.3 [7],[13],[32],[33],[34]             € 36.7 [11],[14],[27],[28],[35]        
Amortized Cost 40,100,000 [7],[32],[33],[34]             40,100,000 [11],[27],[28],[35]              
Fair Value (4,000,000.0) [4],[7],[32],[33],[34]             (3,900,000) [1],[11],[27],[28],[35]              
Investment, Identifier [Axis]: ThermaSys Corp                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (6,100,000)             $ (8,600,000)              
Investment, Identifier [Axis]: ThermaSys Corp, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 11.00% [6],[7],[29],[32],[43] 11.00% [6],[7],[29],[32],[43] 11.00% [6],[7],[29],[32],[43] 11.00% [6],[7],[29],[32],[43] 11.00% [6],[7],[29],[32],[43] 11.00% [6],[7],[29],[32],[43] 11.00% [6],[7],[29],[32],[43] 11.00% [8],[11],[24],[27],[44] 11.00% [8],[11],[24],[27],[44] 11.00% [8],[11],[24],[27],[44] 11.00% [8],[11],[24],[27],[44] 11.00% [8],[11],[24],[27],[44] 11.00% [8],[11],[24],[27],[44] 11.00% [8],[11],[24],[27],[44]  
Rate, Max PIK 11.00% [6],[7],[29],[32],[43] 11.00% [6],[7],[29],[32],[43] 11.00% [6],[7],[29],[32],[43] 11.00% [6],[7],[29],[32],[43] 11.00% [6],[7],[29],[32],[43] 11.00% [6],[7],[29],[32],[43] 11.00% [6],[7],[29],[32],[43] 11.00% [8],[11],[24],[27],[44] 11.00% [8],[11],[24],[27],[44] 11.00% [8],[11],[24],[27],[44] 11.00% [8],[11],[24],[27],[44] 11.00% [8],[11],[24],[27],[44] 11.00% [8],[11],[24],[27],[44] 11.00% [8],[11],[24],[27],[44]  
Base Rate Floor 1.00% [6],[7],[29],[32],[43] 1.00% [6],[7],[29],[32],[43] 1.00% [6],[7],[29],[32],[43] 1.00% [6],[7],[29],[32],[43] 1.00% [6],[7],[29],[32],[43] 1.00% [6],[7],[29],[32],[43] 1.00% [6],[7],[29],[32],[43] 1.00% [11],[24],[27],[44] 1.00% [11],[24],[27],[44] 1.00% [11],[24],[27],[44] 1.00% [11],[24],[27],[44] 1.00% [11],[24],[27],[44] 1.00% [11],[24],[27],[44] 1.00% [11],[24],[27],[44]  
Principal amount $ 10,000,000.0 [7],[13],[29],[32],[43]             $ 9,700,000 [11],[14],[24],[27],[44]              
Amortized Cost 8,300,000 [7],[29],[32],[43]             8,300,000 [11],[24],[27],[44]              
Fair Value (6,100,000) [4],[7],[29],[32],[43]             (8,600,000) [1],[11],[24],[27],[44]              
Investment, Identifier [Axis]: ThermaSys Corp, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ 0             $ 0              
Investment, Identifier [Axis]: ThermaSys Corp, Common Stock, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 17,383,026 [7],[32],[43],[53] 17,383,026 [7],[32],[43],[53] 17,383,026 [7],[32],[43],[53] 17,383,026 [7],[32],[43],[53] 17,383,026 [7],[32],[43],[53] 17,383,026 [7],[32],[43],[53] 17,383,026 [7],[32],[43],[53] 17,383,026 [11],[27],[44],[54] 17,383,026 [11],[27],[44],[54] 17,383,026 [11],[27],[44],[54] 17,383,026 [11],[27],[44],[54] 17,383,026 [11],[27],[44],[54] 17,383,026 [11],[27],[44],[54] 17,383,026 [11],[27],[44],[54]  
Amortized Cost $ 10,200,000 [7],[32],[43],[53]             $ 10,200,000 [11],[27],[44],[54]              
Fair Value 0 [7],[32],[43],[53]             0 [1],[11],[27],[44],[54]              
Investment, Identifier [Axis]: ThermaSys Corp, Common Stock, Equity/Other                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               0             0
Investment, Identifier [Axis]: ThermaSys Corp, Preferred Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ 0             $ 0              
Investment, Identifier [Axis]: ThermaSys Corp, Preferred Stock, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 1,529 [7],[32],[43] 1,529 [7],[32],[43] 1,529 [7],[32],[43] 1,529 [7],[32],[43] 1,529 [7],[32],[43] 1,529 [7],[32],[43] 1,529 [7],[32],[43] 1,529 [11],[27],[44] 1,529 [11],[27],[44] 1,529 [11],[27],[44] 1,529 [11],[27],[44] 1,529 [11],[27],[44] 1,529 [11],[27],[44] 1,529 [11],[27],[44]  
Amortized Cost $ 1,700,000 [7],[32],[43]             $ 1,700,000 [11],[27],[44]              
Fair Value $ 0 [7],[32],[43]             0 [1],[11],[27],[44]              
Investment, Identifier [Axis]: ThermaSys Corp, Preferred Stock, Equity/Other                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               0             0
Investment, Identifier [Axis]: ThermaSys Corp, Senior Secured Loans—First Lien                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ (8,600,000)             (3,500,000)
Investment, Identifier [Axis]: ThreeSixty Group, Consumer Discretionary Distribution & Retail 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[20] 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%                
Rate, PIK [6],[7],[20] 2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%                
Rate, Max PIK [6],[7],[20] 2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%                
Base Rate Floor [6],[7],[20] 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50%                
Principal amount [7],[13],[20] $ 46,100,000                            
Amortized Cost [7],[20] 46,100,000                            
Fair Value [4],[7],[20] $ (45,200,000)                            
Investment, Identifier [Axis]: ThreeSixty Group, Consumer Discretionary Distribution & Retail 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[20] 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%                
Rate, PIK [6],[7],[20] 2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%                
Rate, Max PIK [6],[7],[20] 2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%                
Base Rate Floor [6],[7],[20] 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50%                
Principal amount [7],[13],[20] $ 45,900,000                            
Amortized Cost [7],[20] 45,700,000                            
Fair Value [4],[7],[20] $ (44,900,000)                            
Investment, Identifier [Axis]: ThreeSixty Group, Retailing 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11],[22],[42]               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Rate, PIK [8],[11],[22],[42]               2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%  
Rate, Max PIK [8],[11],[22],[42]               2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%  
Base Rate Floor [11],[22],[42]               1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50%  
Principal amount [11],[14],[22],[42]               $ 46,100,000              
Amortized Cost [11],[22],[42]               46,100,000              
Fair Value [1],[11],[22],[42]               $ (45,100,000)              
Investment, Identifier [Axis]: ThreeSixty Group, Retailing 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11],[42]               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Rate, PIK [8],[11],[42]               2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%  
Rate, Max PIK [8],[11],[42]               2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%  
Base Rate Floor [11],[42]               1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50%  
Principal amount [11],[14],[42]               $ 45,900,000              
Amortized Cost [11],[42]               45,900,000              
Fair Value [1],[11],[42]               $ (44,800,000)              
Investment, Identifier [Axis]: Time Manufacturing Co, Capital Goods | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount | €       € 29.2             € 29.2        
Amortized Cost $ 32,500,000             $ 32,400,000              
Fair Value $ (29,700,000)             $ (29,400,000)              
Investment, Identifier [Axis]: Time Manufacturing Co, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 45,200,000 [7],[13]             $ 45,400,000 [11],[14]              
Amortized Cost 44,400,000 [7]             44,500,000 [11]              
Fair Value $ (42,300,000) [4],[7]             $ (42,700,000) [1],[11]              
Investment, Identifier [Axis]: Time Manufacturing Co, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 5,400,000 [7],[13]             $ 7,300,000 [11],[14]              
Amortized Cost 5,400,000 [7]             7,300,000 [11]              
Fair Value $ (5,100,000) [4],[7]             $ (6,900,000) [1],[11]              
Investment, Identifier [Axis]: Time Manufacturing Co, Capital Goods 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [6],[7] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount | €       € 13.7 [7],[13]             € 13.7 [11],[14]        
Amortized Cost $ 14,400,000 [7]             $ 14,400,000 [11]              
Fair Value $ (13,900,000) [4],[7]             $ (13,800,000) [1],[11]              
Investment, Identifier [Axis]: Time Manufacturing Co, Capital Goods 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 16,700,000 [13],[19]             $ 14,800,000 [14],[18]              
Amortized Cost 16,700,000 [19]             14,800,000 [18]              
Fair Value $ (15,600,000) [4],[19]             (13,900,000) [1],[18]              
Investment, Identifier [Axis]: Toorak Capital Funding LLC, Membership Interest                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ 0             (1,700,000)
Investment, Identifier [Axis]: Total Safety US Inc, Capital Goods | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 11,000,000.0             $ 11,200,000              
Amortized Cost 10,000,000.0             10,100,000              
Fair Value $ (10,500,000)             $ (10,600,000)              
Investment, Identifier [Axis]: Transaction Services Group Ltd, Software & Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount           $ 124.1             $ 124.1    
Amortized Cost $ 85,300,000             $ 85,300,000              
Fair Value $ (81,400,000)             $ (82,600,000)              
Investment, Identifier [Axis]: Transaction Services Group Ltd, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[7],[33] 5.50% [6],[7],[33] 5.50% [6],[7],[33] 5.50% [6],[7],[33] 5.50% [6],[7],[33] 5.50% [6],[7],[33] 5.50% [6],[7],[33] 5.50% [8],[11],[28] 5.50% [8],[11],[28] 5.50% [8],[11],[28] 5.50% [8],[11],[28] 5.50% [8],[11],[28] 5.50% [8],[11],[28] 5.50% [8],[11],[28]  
Base Rate Floor 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [6],[7],[33] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28]  
Principal amount           $ 48.3 [7],[13],[33]             $ 48.3 [11],[14],[28]    
Amortized Cost $ 34,300,000 [7],[33]             $ 34,200,000 [11],[28]              
Fair Value $ (31,700,000) [4],[7],[33]             $ (32,100,000) [1],[11],[28]              
Investment, Identifier [Axis]: Transaction Services Group Ltd, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.50% [6],[7],[20],[33] 5.50% [6],[7],[20],[33] 5.50% [6],[7],[20],[33] 5.50% [6],[7],[20],[33] 5.50% [6],[7],[20],[33] 5.50% [6],[7],[20],[33] 5.50% [6],[7],[20],[33] 5.50% [8],[11],[22],[28] 5.50% [8],[11],[22],[28] 5.50% [8],[11],[22],[28] 5.50% [8],[11],[22],[28] 5.50% [8],[11],[22],[28] 5.50% [8],[11],[22],[28] 5.50% [8],[11],[22],[28]  
Base Rate Floor 0.00% [6],[7],[20],[33] 0.00% [6],[7],[20],[33] 0.00% [6],[7],[20],[33] 0.00% [6],[7],[20],[33] 0.00% [6],[7],[20],[33] 0.00% [6],[7],[20],[33] 0.00% [6],[7],[20],[33] 0.00% [11],[22],[28] 0.00% [11],[22],[28] 0.00% [11],[22],[28] 0.00% [11],[22],[28] 0.00% [11],[22],[28] 0.00% [11],[22],[28] 0.00% [11],[22],[28]  
Principal amount $ 126,200,000 [7],[13],[20],[33]             $ 126,200,000 [11],[14],[22],[28]              
Amortized Cost 123,000,000.0 [7],[20],[33]             122,900,000 [11],[22],[28]              
Fair Value $ (123,900,000) [4],[7],[20],[33]             $ (123,500,000) [1],[11],[22],[28]              
Investment, Identifier [Axis]: TruckPro LLC, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [7],[39] 11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%                
Rate, Stated interest rate [8],[11],[40]               11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%  
Principal amount $ 9,200,000 [7],[39]             $ 9,200,000 [11],[14],[40]              
Amortized Cost 9,200,000 [7],[39]             9,200,000 [11],[40]              
Fair Value $ (9,200,000) [7],[39]             $ (9,100,000) [1],[11],[40]              
Investment, Identifier [Axis]: Ultra Electronics Holdings PLC, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 3.50% [6],[33],[39],[41] 3.50% [6],[33],[39],[41] 3.50% [6],[33],[39],[41] 3.50% [6],[33],[39],[41] 3.50% [6],[33],[39],[41] 3.50% [6],[33],[39],[41] 3.50% [6],[33],[39],[41] 3.75% [8],[11],[28],[40] 3.75% [8],[11],[28],[40] 3.75% [8],[11],[28],[40] 3.75% [8],[11],[28],[40] 3.75% [8],[11],[28],[40] 3.75% [8],[11],[28],[40] 3.75% [8],[11],[28],[40]  
Base Rate Floor 0.50% [6],[33],[39],[41] 0.50% [6],[33],[39],[41] 0.50% [6],[33],[39],[41] 0.50% [6],[33],[39],[41] 0.50% [6],[33],[39],[41] 0.50% [6],[33],[39],[41] 0.50% [6],[33],[39],[41] 0.50% [11],[28],[40] 0.50% [11],[28],[40] 0.50% [11],[28],[40] 0.50% [11],[28],[40] 0.50% [11],[28],[40] 0.50% [11],[28],[40] 0.50% [11],[28],[40]  
Principal amount $ 1,800,000 [13],[33],[39],[41]             $ 1,800,000 [11],[14],[28],[40]              
Amortized Cost 1,800,000 [33],[39],[41]             1,800,000 [11],[28],[40]              
Fair Value $ (1,700,000) [4],[33],[39],[41]             $ (1,700,000) [1],[11],[28],[40]              
Investment, Identifier [Axis]: Ultra Electronics Holdings PLC, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 3.25% [6],[7],[33],[39] 3.25% [6],[7],[33],[39] 3.25% [6],[7],[33],[39] 3.25% [6],[7],[33],[39] 3.25% [6],[7],[33],[39] 3.25% [6],[7],[33],[39] 3.25% [6],[7],[33],[39] 3.75% [8],[11],[28],[40] 3.75% [8],[11],[28],[40] 3.75% [8],[11],[28],[40] 3.75% [8],[11],[28],[40] 3.75% [8],[11],[28],[40] 3.75% [8],[11],[28],[40] 3.75% [8],[11],[28],[40]  
Base Rate Floor 0.00% [6],[7],[33],[39] 0.00% [6],[7],[33],[39] 0.00% [6],[7],[33],[39] 0.00% [6],[7],[33],[39] 0.00% [6],[7],[33],[39] 0.00% [6],[7],[33],[39] 0.00% [6],[7],[33],[39] 0.00% [11],[28],[40] 0.00% [11],[28],[40] 0.00% [11],[28],[40] 0.00% [11],[28],[40] 0.00% [11],[28],[40] 0.00% [11],[28],[40] 0.00% [11],[28],[40]  
Principal amount | €       € 1.4 [7],[13],[33],[39]             € 1.4 [11],[14],[28],[40]        
Amortized Cost $ 1,600,000 [7],[33],[39]             $ 1,600,000 [11],[28],[40]              
Fair Value $ (1,400,000) [4],[7],[33],[39]             $ (1,400,000) [1],[11],[28],[40]              
Investment, Identifier [Axis]: Ultra Electronics Holdings PLC, Capital Goods 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.25% [7],[33] 7.25% [7],[33] 7.25% [7],[33] 7.25% [7],[33] 7.25% [7],[33] 7.25% [7],[33] 7.25% [7],[33] 7.25% [8],[11],[28] 7.25% [8],[11],[28] 7.25% [8],[11],[28] 7.25% [8],[11],[28] 7.25% [8],[11],[28] 7.25% [8],[11],[28] 7.25% [8],[11],[28]  
Base Rate Floor 0.50% [7],[33] 0.50% [7],[33] 0.50% [7],[33] 0.50% [7],[33] 0.50% [7],[33] 0.50% [7],[33] 0.50% [7],[33] 0.50% [11],[28] 0.50% [11],[28] 0.50% [11],[28] 0.50% [11],[28] 0.50% [11],[28] 0.50% [11],[28] 0.50% [11],[28]  
Principal amount $ 62,900,000 [7],[33]             $ 62,900,000 [11],[14],[28]              
Amortized Cost 61,100,000 [7],[33]             61,100,000 [11],[28]              
Fair Value $ (58,700,000) [7],[33]             $ (58,200,000) [1],[11],[28]              
Investment, Identifier [Axis]: Ultra Electronics Holdings PLC, Capital Goods 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [11],[28]               9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%  
Rate, PIK 9.00% [7],[33] 9.00% [7],[33] 9.00% [7],[33] 9.00% [7],[33] 9.00% [7],[33] 9.00% [7],[33] 9.00% [7],[33] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28] 0.00% [11],[28]  
Rate, Max PIK 9.00% [7],[33] 9.00% [7],[33] 9.00% [7],[33] 9.00% [7],[33] 9.00% [7],[33] 9.00% [7],[33] 9.00% [7],[33] 9.00% [11],[28] 9.00% [11],[28] 9.00% [11],[28] 9.00% [11],[28] 9.00% [11],[28] 9.00% [11],[28] 9.00% [11],[28]  
Base Rate Floor 0.50% [7],[33] 0.50% [7],[33] 0.50% [7],[33] 0.50% [7],[33] 0.50% [7],[33] 0.50% [7],[33] 0.50% [7],[33] 0.50% [11],[28] 0.50% [11],[28] 0.50% [11],[28] 0.50% [11],[28] 0.50% [11],[28] 0.50% [11],[28] 0.50% [11],[28]  
Principal amount $ 61,800,000 [7],[33]             $ 58,200,000 [11],[14],[28]              
Amortized Cost 60,100,000 [7],[33]             56,500,000 [11],[28]              
Fair Value $ (57,600,000) [7],[33]             $ (53,400,000) [1],[11],[28]              
Investment, Identifier [Axis]: Ultra Electronics Holdings PLC, Private Equity, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 683,240,044 [7],[32],[33] 683,240,044 [7],[32],[33] 683,240,044 [7],[32],[33] 683,240,044 [7],[32],[33] 683,240,044 [7],[32],[33] 683,240,044 [7],[32],[33] 683,240,044 [7],[32],[33] 683,240,044 [11],[27],[28] 683,240,044 [11],[27],[28] 683,240,044 [11],[27],[28] 683,240,044 [11],[27],[28] 683,240,044 [11],[27],[28] 683,240,044 [11],[27],[28] 683,240,044 [11],[27],[28]  
Amortized Cost $ 7,200,000 [7],[32],[33]             $ 7,200,000 [11],[27],[28]              
Fair Value $ (6,800,000) [7],[32],[33]             $ (6,700,000) [1],[11],[27],[28]              
Investment, Identifier [Axis]: Ultra Electronics Holdings PLC, Private Equity, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 1,272,105 [7],[32],[33] 1,272,105 [7],[32],[33] 1,272,105 [7],[32],[33] 1,272,105 [7],[32],[33] 1,272,105 [7],[32],[33] 1,272,105 [7],[32],[33] 1,272,105 [7],[32],[33] 1,272,105 [11],[27],[28] 1,272,105 [11],[27],[28] 1,272,105 [11],[27],[28] 1,272,105 [11],[27],[28] 1,272,105 [11],[27],[28] 1,272,105 [11],[27],[28] 1,272,105 [11],[27],[28]  
Amortized Cost $ 1,300,000 [7],[32],[33]             $ 1,300,000 [11],[27],[28]              
Fair Value $ (1,200,000) [7],[32],[33]             $ (1,200,000) [1],[11],[27],[28]              
Investment, Identifier [Axis]: Unifrax I LLC / Unifrax Holding Co, Capital Goods | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount $ 2,800,000             $ 2,800,000              
Amortized Cost 2,700,000             2,700,000              
Fair Value $ (2,600,000)             $ (2,500,000)              
Investment, Identifier [Axis]: Valeo Foods Group Ltd, Food, Beverage & Tobacco | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | £         £ 9.3             £ 9.3      
Amortized Cost $ 11,800,000             $ 11,800,000              
Fair Value $ (9,600,000)             $ (9,900,000)              
Investment, Identifier [Axis]: Valeo Foods Group Ltd, Food, Beverage & Tobacco 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.50% [6],[7],[33] 7.50% [6],[7],[33] 7.50% [6],[7],[33] 7.50% [6],[7],[33] 7.50% [6],[7],[33] 7.50% [6],[7],[33] 7.50% [6],[7],[33] 7.50% [8],[11],[28] 7.50% [8],[11],[28] 7.50% [8],[11],[28] 7.50% [8],[11],[28] 7.50% [8],[11],[28] 7.50% [8],[11],[28] 7.50% [8],[11],[28]  
Base Rate Floor [6],[7],[33] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | €       € 3.8 [7],[13],[33]             € 3.8 [11],[14],[28]        
Amortized Cost $ 4,000,000.0 [7],[33]             $ 4,000,000.0 [11],[28]              
Fair Value $ (3,400,000) [4],[7],[33]             $ (3,600,000) [1],[11],[28]              
Investment, Identifier [Axis]: Valeo Foods Group Ltd, Food, Beverage & Tobacco 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.50% [6],[19],[33] 7.50% [6],[19],[33] 7.50% [6],[19],[33] 7.50% [6],[19],[33] 7.50% [6],[19],[33] 7.50% [6],[19],[33] 7.50% [6],[19],[33] 7.50% [8],[18],[28] 7.50% [8],[18],[28] 7.50% [8],[18],[28] 7.50% [8],[18],[28] 7.50% [8],[18],[28] 7.50% [8],[18],[28] 7.50% [8],[18],[28]  
Base Rate Floor [6],[19],[33] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | €       € 2.3 [13],[19],[33]             € 2.3 [14],[18],[28]        
Amortized Cost $ 3,100,000 [19],[33]             $ 3,100,000 [18],[28]              
Fair Value $ (2,600,000) [4],[19],[33]             $ (2,800,000) [1],[18],[28]              
Investment, Identifier [Axis]: Vantage Specialty Chemicals Inc, Materials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11],[40]               8.25% 8.25% 8.25% 8.25% 8.25% 8.25% 8.25%  
Base Rate Floor [11],[40]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [11],[14],[40]               $ 800,000              
Amortized Cost [11],[40]               700,000              
Fair Value [1],[11],[40]               $ (700,000)              
Investment, Identifier [Axis]: Varsity Brands Inc, Consumer Durables & Apparel | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 4,000,000.0             $ 4,000,000.0              
Amortized Cost 3,800,000             3,800,000              
Fair Value $ (3,700,000)             $ (3,800,000)              
Investment, Identifier [Axis]: Versatile Processing Group Inc, Class A - 2 Units, Materials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares [27],[54]               3,637,500 3,637,500 3,637,500 3,637,500 3,637,500 3,637,500 3,637,500  
Amortized Cost [27],[54]               $ 3,600,000              
Fair Value [1],[27],[54]               $ 0              
Investment, Identifier [Axis]: Version1 Software Ltd, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[18],[28]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Rate, PIK [8],[18],[28]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Rate, Max PIK [8],[18],[28]               1.70% 1.70% 1.70% 1.70% 1.70% 1.70% 1.70%  
Base Rate Floor [18],[28]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | € [14],[18],[28]                     € 2.4        
Amortized Cost [18],[28]               $ 2,400,000              
Fair Value [1],[18],[28]               $ (2,300,000)              
Investment, Identifier [Axis]: Version1 Software Ltd, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[33] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Rate, PIK [6],[7],[33] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Rate, Max PIK [6],[7],[33] 1.70% 1.70% 1.70% 1.70% 1.70% 1.70% 1.70%                
Base Rate Floor [6],[7],[33] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | £ [7],[13],[33]         £ 1.1                    
Amortized Cost [7],[33] $ 1,300,000                            
Fair Value [4],[7],[33] $ (1,300,000)                            
Investment, Identifier [Axis]: Version1 Software Ltd, Software & Services 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Rate, PIK 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Rate, Max PIK 1.70% 1.70% 1.70% 1.70% 1.70% 1.70% 1.70% 1.70% 1.70% 1.70% 1.70% 1.70% 1.70% 1.70%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | €       € 2.5             € 2.5        
Amortized Cost $ 2,500,000             $ 2,500,000              
Fair Value $ (2,600,000)             $ (2,500,000)              
Investment, Identifier [Axis]: Version1 Software Ltd, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19],[33] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Rate, PIK [6],[19],[33] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Rate, Max PIK [6],[19],[33] 1.70% 1.70% 1.70% 1.70% 1.70% 1.70% 1.70%                
Base Rate Floor [6],[19],[33] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | € [13],[19],[33]       € 1.1                      
Amortized Cost [19],[33] $ 1,100,000                            
Fair Value [4],[19],[33] $ (1,100,000)                            
Investment, Identifier [Axis]: Version1 Software Ltd, Software & Services 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Rate, PIK 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Rate, Max PIK 1.70% 1.70% 1.70% 1.70% 1.70% 1.70% 1.70% 1.70% 1.70% 1.70% 1.70% 1.70% 1.70% 1.70%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | £         £ 4.0             £ 4.0      
Amortized Cost $ 4,700,000             $ 4,700,000              
Fair Value $ (4,800,000)             $ (4,700,000)              
Investment, Identifier [Axis]: VetCor Professional Practices LLC, Health Care Equipment & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[7],[41] 5.75% [6],[7],[41] 5.75% [6],[7],[41] 5.75% [6],[7],[41] 5.75% [6],[7],[41] 5.75% [6],[7],[41] 5.75% [6],[7],[41] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11]  
Base Rate Floor 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 88,800,000 [7],[13],[41]             $ 82,300,000 [11],[14]              
Amortized Cost 88,000,000.0 [7],[41]             81,500,000 [11]              
Fair Value $ (89,100,000) [4],[7],[41]             $ (80,900,000) [1],[11]              
Investment, Identifier [Axis]: VetCor Professional Practices LLC, Health Care Equipment & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [6],[7] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11] 5.75% [8],[11]  
Base Rate Floor 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [6],[7] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 700,000 [7],[13]             $ 1,800,000 [11],[14]              
Amortized Cost 600,000 [7]             1,700,000 [11]              
Fair Value $ (700,000) [4],[7]             $ (1,800,000) [1],[11]              
Investment, Identifier [Axis]: VetCor Professional Practices LLC, Health Care Equipment & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 3,800,000 [13],[19]             $ 11,000,000.0 [14],[18]              
Amortized Cost 3,800,000 [19]             10,900,000 [18]              
Fair Value $ (3,800,000) [4],[19]             $ (10,800,000) [1],[18]              
Investment, Identifier [Axis]: VetCor Professional Practices LLC, Health Care Equipment & Services 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [6],[19] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18] 5.75% [8],[18]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 6,700,000 [13],[19]             $ 4,900,000 [14],[18]              
Amortized Cost 6,600,000 [19]             4,900,000 [18]              
Fair Value (6,700,000) [4],[19]             (4,800,000) [1],[18]              
Investment, Identifier [Axis]: Warren Resources Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value (18,700,000)             (18,600,000)             (18,700,000)
Investment, Identifier [Axis]: Warren Resources Inc, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (23,500,000)             $ (29,200,000)             (20,400,000)
Investment, Identifier [Axis]: Warren Resources Inc, Common Stock, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 3,483,788 [7],[32],[34] 3,483,788 [7],[32],[34] 3,483,788 [7],[32],[34] 3,483,788 [7],[32],[34] 3,483,788 [7],[32],[34] 3,483,788 [7],[32],[34] 3,483,788 [7],[32],[34] 3,483,788 [11],[27],[35] 3,483,788 [11],[27],[35] 3,483,788 [11],[27],[35] 3,483,788 [11],[27],[35] 3,483,788 [11],[27],[35] 3,483,788 [11],[27],[35] 3,483,788 [11],[27],[35]  
Amortized Cost $ 12,800,000 [7],[32],[34]             $ 12,800,000 [11],[27],[35]              
Fair Value $ (23,500,000) [7],[32],[34]             $ (29,200,000) [1],[11],[27],[35]              
Investment, Identifier [Axis]: Warren Resources Inc, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 9.00% [6],[7],[34] 9.00% [6],[7],[34] 9.00% [6],[7],[34] 9.00% [6],[7],[34] 9.00% [6],[7],[34] 9.00% [6],[7],[34] 9.00% [6],[7],[34] 9.00% [8] 9.00% [8] 9.00% [8] 9.00% [8] 9.00% [8] 9.00% [8] 9.00% [8]  
Rate, PIK 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [8] 1.00% [8] 1.00% [8] 1.00% [8] 1.00% [8] 1.00% [8] 1.00% [8]  
Rate, Max PIK 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [8] 1.00% [8] 1.00% [8] 1.00% [8] 1.00% [8] 1.00% [8] 1.00% [8]  
Base Rate Floor 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% [6],[7],[34] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 18,700,000 [7],[13],[34]             $ 18,600,000 [14]              
Amortized Cost 18,000,000.0 [7],[34]             17,800,000              
Fair Value $ (18,700,000) [4],[7],[34]             $ (18,600,000) [1]              
Investment, Identifier [Axis]: Wealth Enhancement Group LLC, Diversified Financials 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[11],[28]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base Rate Floor [11],[28]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [11],[14],[28]               $ 31,100,000              
Amortized Cost [11],[28]               31,000,000.0              
Fair Value [1],[11],[28]               $ (30,700,000)              
Investment, Identifier [Axis]: Wealth Enhancement Group LLC, Diversified Financials 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[18],[28]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base Rate Floor [18],[28]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [14],[18],[28]               $ 3,300,000              
Amortized Cost [18],[28]               3,300,000              
Fair Value [1],[18],[28]               $ (3,200,000)              
Investment, Identifier [Axis]: Wealth Enhancement Group LLC, Diversified Financials 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[18],[28]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base Rate Floor [18],[28]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [14],[18],[28]               $ 2,100,000              
Amortized Cost [18],[28]               2,100,000              
Fair Value [1],[18],[28]               $ (2,000,000.0)              
Investment, Identifier [Axis]: Wealth Enhancement Group LLC, Financial Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount $ 28,100,000                            
Amortized Cost 27,900,000                            
Fair Value $ (27,900,000)                            
Investment, Identifier [Axis]: Wealth Enhancement Group LLC, Financial Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[7],[33] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base Rate Floor [6],[7],[33] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [7],[13],[33] $ 3,800,000                            
Amortized Cost [7],[33] 3,800,000                            
Fair Value [4],[7],[33] $ (3,800,000)                            
Investment, Identifier [Axis]: Wealth Enhancement Group LLC, Financial Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19],[33] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base Rate Floor [6],[19],[33] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[19],[33] $ 2,400,000                            
Amortized Cost [19],[33] 2,400,000                            
Fair Value [4],[19],[33] $ (2,400,000)                            
Investment, Identifier [Axis]: Wealth Enhancement Group LLC, Financial Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [6],[19],[33] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base Rate Floor [6],[19],[33] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[19],[33] $ 2,100,000                            
Amortized Cost [19],[33] 2,100,000                            
Fair Value [4],[19],[33] $ (2,100,000)                            
Investment, Identifier [Axis]: West Corp, Commercial & Professional Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00%                
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount $ 4,800,000                            
Amortized Cost 4,800,000                            
Fair Value $ (4,200,000)                            
Investment, Identifier [Axis]: West Corp, Software & Services 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate               4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00%  
Base Rate Floor               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount               $ 12,100,000              
Amortized Cost               12,000,000.0              
Fair Value               $ (11,200,000)              
Investment, Identifier [Axis]: West Corp, Software & Services 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate               3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50%  
Base Rate Floor               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount               $ 2,500,000              
Amortized Cost               2,500,000              
Fair Value               $ (2,300,000)              
Investment, Identifier [Axis]: Wittur Holding GmbH, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 8.50% [6],[7],[29],[32],[33] 8.50% [6],[7],[29],[32],[33] 8.50% [6],[7],[29],[32],[33] 8.50% [6],[7],[29],[32],[33] 8.50% [6],[7],[29],[32],[33] 8.50% [6],[7],[29],[32],[33] 8.50% [6],[7],[29],[32],[33] 8.50% [8],[11],[28] 8.50% [8],[11],[28] 8.50% [8],[11],[28] 8.50% [8],[11],[28] 8.50% [8],[11],[28] 8.50% [8],[11],[28] 8.50% [8],[11],[28]  
Rate, PIK 1.00% [6],[7],[29],[32],[33] 1.00% [6],[7],[29],[32],[33] 1.00% [6],[7],[29],[32],[33] 1.00% [6],[7],[29],[32],[33] 1.00% [6],[7],[29],[32],[33] 1.00% [6],[7],[29],[32],[33] 1.00% [6],[7],[29],[32],[33] 1.00% [8],[11],[28] 1.00% [8],[11],[28] 1.00% [8],[11],[28] 1.00% [8],[11],[28] 1.00% [8],[11],[28] 1.00% [8],[11],[28] 1.00% [8],[11],[28]  
Rate, Max PIK 1.00% [6],[7],[29],[32],[33] 1.00% [6],[7],[29],[32],[33] 1.00% [6],[7],[29],[32],[33] 1.00% [6],[7],[29],[32],[33] 1.00% [6],[7],[29],[32],[33] 1.00% [6],[7],[29],[32],[33] 1.00% [6],[7],[29],[32],[33] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Base Rate Floor [6],[7],[29],[32],[33] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | €       € 113.4 [7],[13],[29],[32],[33]             € 113.4 [11],[14],[28]        
Amortized Cost $ 122,500,000 [7],[29],[32],[33]             $ 122,500,000 [11],[28]              
Fair Value $ (64,300,000) [4],[7],[29],[32],[33]             $ (86,100,000) [1],[11],[28]              
Investment, Identifier [Axis]: Wittur Holding GmbH, Capital Goods | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%  
Rate, PIK 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Rate, Max PIK 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Base Rate Floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | €       € 121.1             € 121.1        
Amortized Cost $ 132,400,000             $ 132,400,000              
Fair Value $ (68,600,000)             $ (92,000,000.0)              
Investment, Identifier [Axis]: Woolpert Inc, Capital Goods | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 52,900,000             $ 53,000,000.0              
Amortized Cost 52,400,000             52,600,000              
Fair Value $ (50,300,000)             $ (51,600,000)              
Investment, Identifier [Axis]: Woolpert Inc, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[7],[16],[17],[20],[21],[41] 6.00% [6],[7],[16],[17],[20],[21],[41] 6.00% [6],[7],[16],[17],[20],[21],[41] 6.00% [6],[7],[16],[17],[20],[21],[41] 6.00% [6],[7],[16],[17],[20],[21],[41] 6.00% [6],[7],[16],[17],[20],[21],[41] 6.00% [6],[7],[16],[17],[20],[21],[41] 6.00% [8],[9],[10],[22],[23],[42] 6.00% [8],[9],[10],[22],[23],[42] 6.00% [8],[9],[10],[22],[23],[42] 6.00% [8],[9],[10],[22],[23],[42] 6.00% [8],[9],[10],[22],[23],[42] 6.00% [8],[9],[10],[22],[23],[42] 6.00% [8],[9],[10],[22],[23],[42]  
Base Rate Floor 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [6],[7],[16],[17],[20],[21],[41] 1.00% [9],[10],[22],[23],[42] 1.00% [9],[10],[22],[23],[42] 1.00% [9],[10],[22],[23],[42] 1.00% [9],[10],[22],[23],[42] 1.00% [9],[10],[22],[23],[42] 1.00% [9],[10],[22],[23],[42] 1.00% [9],[10],[22],[23],[42]  
Principal amount $ 90,800,000 [7],[13],[16],[17],[20],[21],[41]             $ 91,000,000.0 [9],[10],[14],[22],[23],[42]              
Amortized Cost 85,100,000 [7],[16],[17],[20],[21],[41]             85,100,000 [9],[10],[22],[23],[42]              
Fair Value $ (86,200,000) [4],[7],[16],[17],[20],[21],[41]             $ (88,600,000) [1],[9],[10],[22],[23],[42]              
Investment, Identifier [Axis]: Woolpert Inc, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [6],[7] 6.00% [8],[11] 6.00% [8],[11] 6.00% [8],[11] 6.00% [8],[11] 6.00% [8],[11] 6.00% [8],[11] 6.00% [8],[11]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Principal amount $ 68,300,000 [7],[13]             $ 68,500,000 [11],[14]              
Amortized Cost 68,300,000 [7]             68,500,000 [11]              
Fair Value $ (64,900,000) [4],[7]             $ (66,700,000) [1],[11]              
Investment, Identifier [Axis]: Woolpert Inc, Capital Goods 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [6],[19] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18] 6.00% [8],[18]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 3,700,000 [13],[19]             $ 3,700,000 [14],[18]              
Amortized Cost 3,700,000 [19]             3,700,000 [18]              
Fair Value $ (3,500,000) [4],[19]             $ (3,600,000) [1],[18]              
Investment, Identifier [Axis]: Worldwise Inc, Class A Private Equity, Household & Personal Products                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 32,109 [7],[32] 32,109 [7],[32] 32,109 [7],[32] 32,109 [7],[32] 32,109 [7],[32] 32,109 [7],[32] 32,109 [7],[32] 32,109 [11],[27] 32,109 [11],[27] 32,109 [11],[27] 32,109 [11],[27] 32,109 [11],[27] 32,109 [11],[27] 32,109 [11],[27]  
Amortized Cost $ 1,600,000 [7],[32]             $ 1,600,000 [11],[27]              
Fair Value $ (1,600,000) [7],[32]             $ (1,600,000) [1],[11],[27]              
Investment, Identifier [Axis]: Worldwise Inc, Class B Private Equity, Household & Personal Products                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 32,109 [7],[32] 32,109 [7],[32] 32,109 [7],[32] 32,109 [7],[32] 32,109 [7],[32] 32,109 [7],[32] 32,109 [7],[32] 32,109 [11],[27] 32,109 [11],[27] 32,109 [11],[27] 32,109 [11],[27] 32,109 [11],[27] 32,109 [11],[27] 32,109 [11],[27]  
Amortized Cost $ 1,600,000 [7],[32]             $ 1,600,000 [11],[27]              
Fair Value $ (300,000) [7],[32]             $ (400,000) [1],[11],[27]              
Investment, Identifier [Axis]: Worldwise Inc, Household & Personal Products | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount $ 64,500,000             $ 64,700,000              
Amortized Cost 61,700,000             61,700,000              
Fair Value $ (59,300,000)             $ (59,800,000)              
Investment, Identifier [Axis]: Worldwise Inc, Household & Personal Products 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Principal amount $ 46,000,000.0 [7],[13]             $ 26,300,000 [11],[14]              
Amortized Cost 45,800,000 [7]             26,300,000 [11]              
Fair Value $ (42,300,000) [4],[7]             $ (24,400,000) [1],[11]              
Investment, Identifier [Axis]: Worldwise Inc, Household & Personal Products 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [6],[7] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11]  
Base Rate Floor 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [6],[7] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Principal amount $ 7,400,000 [7],[13]             $ 20,000,000.0 [11],[14]              
Amortized Cost 7,400,000 [7]             19,800,000 [11]              
Fair Value $ (6,800,000) [4],[7]             $ (18,500,000) [1],[11]              
Investment, Identifier [Axis]: Worldwise Inc, Household & Personal Products 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11] 6.25% [8],[11]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11] 1.00% [11]  
Principal amount $ 15,500,000 [13],[19]             $ 7,400,000 [11],[14]              
Amortized Cost 15,500,000 [19]             7,400,000 [11]              
Fair Value $ (14,300,000) [4],[19]             $ (6,800,000) [1],[11]              
Investment, Identifier [Axis]: Worldwise Inc, Household & Personal Products 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [6],[19] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18] 6.25% [8],[18]  
Base Rate Floor 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [6],[19] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18] 1.00% [18]  
Principal amount $ 6,800,000 [13],[19]             $ 15,500,000 [14],[18]              
Amortized Cost 6,800,000 [19]             15,500,000 [18]              
Fair Value $ (6,300,000) [4],[19]             $ (14,400,000) [1],[18]              
Investment, Identifier [Axis]: Worldwise Inc, Household & Personal Products 5                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate [8],[18]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base Rate Floor [18]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [14],[18]               $ 6,800,000              
Amortized Cost [18]               6,800,000              
Fair Value [1],[18]               $ (6,300,000)              
Investment, Identifier [Axis]: Yak Access LLC, Capital Goods | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.40% 6.40% 6.40% 6.40% 6.40% 6.40% 6.40%                
Base Rate Floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount $ 500,000                            
Amortized Cost 400,000                            
Fair Value $ (400,000)                            
Investment, Identifier [Axis]: Yak Access LLC, Capital Goods 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate               8.25% 8.25% 8.25% 8.25% 8.25% 8.25% 8.25%  
Base Rate Floor               2.00% 2.00% 2.00% 2.00% 2.00% 2.00% 2.00%  
Principal amount               $ 200,000              
Amortized Cost               200,000              
Fair Value               $ (200,000)              
Investment, Identifier [Axis]: Yak Access LLC, Capital Goods 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Base Rate Floor               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount               $ 800,000              
Amortized Cost               600,000              
Fair Value               $ (300,000)              
Investment, Identifier [Axis]: Yak Access LLC, Common Stock, Capital Goods | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 1,256 1,256 1,256 1,256 1,256 1,256 1,256                
Amortized Cost $ 0                            
Fair Value $ 0                            
Investment, Identifier [Axis]: Yak Access LLC, Preferred Stock, Capital Goods | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of Shares | shares 301,310 301,310 301,310 301,310 301,310 301,310 301,310                
Amortized Cost $ 0                            
Fair Value $ 0                            
Investment, Identifier [Axis]: Zendesk Inc, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 7.00% [6],[7],[41] 7.00% [6],[7],[41] 7.00% [6],[7],[41] 7.00% [6],[7],[41] 7.00% [6],[7],[41] 7.00% [6],[7],[41] 7.00% [6],[7],[41] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11] 6.50% [8],[11]  
Rate, PIK 0.00% [6],[7],[41] 0.00% [6],[7],[41] 0.00% [6],[7],[41] 0.00% [6],[7],[41] 0.00% [6],[7],[41] 0.00% [6],[7],[41] 0.00% [6],[7],[41] 0.00% [8],[11] 0.00% [8],[11] 0.00% [8],[11] 0.00% [8],[11] 0.00% [8],[11] 0.00% [8],[11] 0.00% [8],[11]  
Rate, Max PIK 3.50% [6],[7],[41] 3.50% [6],[7],[41] 3.50% [6],[7],[41] 3.50% [6],[7],[41] 3.50% [6],[7],[41] 3.50% [6],[7],[41] 3.50% [6],[7],[41] 3.50% [8],[11] 3.50% [8],[11] 3.50% [8],[11] 3.50% [8],[11] 3.50% [8],[11] 3.50% [8],[11] 3.50% [8],[11]  
Base Rate Floor 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [6],[7],[41] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11] 0.80% [11]  
Principal amount $ 58,100,000 [7],[13],[41]             $ 58,100,000 [11],[14]              
Amortized Cost 57,600,000 [7],[41]             57,500,000 [11]              
Fair Value $ (58,000,000.0) [4],[7],[41]             $ (57,500,000) [1],[11]              
Investment, Identifier [Axis]: Zendesk Inc, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18]  
Rate, PIK 0.00% [6],[19] 0.00% [6],[19] 0.00% [6],[19] 0.00% [6],[19] 0.00% [6],[19] 0.00% [6],[19] 0.00% [6],[19] 0.00% [8],[18] 0.00% [8],[18] 0.00% [8],[18] 0.00% [8],[18] 0.00% [8],[18] 0.00% [8],[18] 0.00% [8],[18]  
Rate, Max PIK 3.50% [6],[19] 3.50% [6],[19] 3.50% [6],[19] 3.50% [6],[19] 3.50% [6],[19] 3.50% [6],[19] 3.50% [6],[19] 3.50% [8],[18] 3.50% [8],[18] 3.50% [8],[18] 3.50% [8],[18] 3.50% [8],[18] 3.50% [8],[18] 3.50% [8],[18]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 6,000,000.0 [13],[19]             $ 14,500,000 [14],[18]              
Amortized Cost 6,000,000.0 [19]             14,400,000 [18]              
Fair Value $ (6,000,000.0) [4],[19]             $ (14,400,000) [1],[18]              
Investment, Identifier [Axis]: Zendesk Inc, Software & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [6],[19] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18] 6.50% [8],[18]  
Rate, PIK 0.00% [6],[19] 0.00% [6],[19] 0.00% [6],[19] 0.00% [6],[19] 0.00% [6],[19] 0.00% [6],[19] 0.00% [6],[19] 0.00% [8],[18] 0.00% [8],[18] 0.00% [8],[18] 0.00% [8],[18] 0.00% [8],[18] 0.00% [8],[18] 0.00% [8],[18]  
Rate, Max PIK 3.50% [6],[19] 3.50% [6],[19] 3.50% [6],[19] 3.50% [6],[19] 3.50% [6],[19] 3.50% [6],[19] 3.50% [6],[19] 3.50% [8],[18] 3.50% [8],[18] 3.50% [8],[18] 3.50% [8],[18] 3.50% [8],[18] 3.50% [8],[18] 3.50% [8],[18]  
Base Rate Floor 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [6],[19] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18] 0.80% [18]  
Principal amount $ 14,500,000 [13],[19]             $ 6,000,000.0 [14],[18]              
Amortized Cost 14,400,000 [19]             6,000,000.0 [18]              
Fair Value $ (14,500,000) [4],[19]             $ (5,900,000) [1],[18]              
Investment, Identifier [Axis]: athenahealth Inc, Health Care Equipment & Services 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50%  
Base Rate Floor 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount $ 7,100,000             $ 7,100,000              
Amortized Cost 6,400,000             6,400,000              
Fair Value $ (6,700,000)             $ (6,400,000)              
Investment, Identifier [Axis]: athenahealth Inc, Health Care Equipment & Services 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50%  
Base Rate Floor 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount $ 900,000             $ 900,000              
Amortized Cost 800,000             900,000              
Fair Value $ (800,000)             $ (800,000)              
Investment, Identifier [Axis]: athenahealth Inc, Health Care Equipment & Services 3 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Stated interest rate 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Principal amount $ 5,500,000             $ 5,500,000              
Amortized Cost 4,800,000             4,800,000              
Fair Value (4,500,000)             (4,100,000)              
Investment, Identifier [Axis]: athenahealth Inc, Preferred Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value $ (230,700,000)             (231,200,000)              
Investment, Identifier [Axis]: athenahealth Inc, Preferred Stock, Equity/Other                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ (231,200,000)             0
Investment, Identifier [Axis]: athenahealth Inc, Preferred Stock, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 10.80% [6],[7],[43] 10.80% [6],[7],[43] 10.80% [6],[7],[43] 10.80% [6],[7],[43] 10.80% [6],[7],[43] 10.80% [6],[7],[43] 10.80% [6],[7],[43] 10.80% [8],[11],[44] 10.80% [8],[11],[44] 10.80% [8],[11],[44] 10.80% [8],[11],[44] 10.80% [8],[11],[44] 10.80% [8],[11],[44] 10.80% [8],[11],[44]  
Rate, Max PIK 10.80% [6],[7],[43] 10.80% [6],[7],[43] 10.80% [6],[7],[43] 10.80% [6],[7],[43] 10.80% [6],[7],[43] 10.80% [6],[7],[43] 10.80% [6],[7],[43] 10.80% [8],[11],[44] 10.80% [8],[11],[44] 10.80% [8],[11],[44] 10.80% [8],[11],[44] 10.80% [8],[11],[44] 10.80% [8],[11],[44] 10.80% [8],[11],[44]  
Number of Shares | shares 267,493 [7],[43] 267,493 [7],[43] 267,493 [7],[43] 267,493 [7],[43] 267,493 [7],[43] 267,493 [7],[43] 267,493 [7],[43] 267,493,473 [11],[44] 267,493,473 [11],[44] 267,493,473 [11],[44] 267,493,473 [11],[44] 267,493,473 [11],[44] 267,493,473 [11],[44] 267,493,473 [11],[44]  
Amortized Cost $ 262,200,000 [7],[43]             $ 262,200,000 [11],[44]              
Fair Value $ (230,700,000) [4],[7],[43]             $ (231,200,000) [1],[11],[44]              
Investment, Identifier [Axis]: athenahealth Inc, Preferred Stock, Health Care Equipment & Services | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, PIK 10.80% 10.80% 10.80% 10.80% 10.80% 10.80% 10.80% 10.80% 10.80% 10.80% 10.80% 10.80% 10.80% 10.80%  
Rate, Max PIK 10.80% 10.80% 10.80% 10.80% 10.80% 10.80% 10.80% 10.80% 10.80% 10.80% 10.80% 10.80% 10.80% 10.80%  
Number of Shares | shares 50,000,000 50,000,000 50,000,000 50,000,000 50,000,000 50,000,000 50,000,000 50,000,000 50,000,000 50,000,000 50,000,000 50,000,000 50,000,000 50,000,000  
Amortized Cost $ 47,500,000             $ 47,500,000              
Fair Value $ (43,100,000)             (43,200,000)              
Investment, Identifier [Axis]: athenahealth Inc, Senior Secured Loans—First Lien -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               0             0
Investment, Identifier [Axis]: athenahealth Inc, Subordinated Debt                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair Value               $ 0             $ 0
Investment, Identifier [Axis]: iNova Pharmaceuticals (Australia) Pty Limited, Pharmaceuticals, Biotechnology & Life Sciences                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% [6],[19],[33] 6.50% [6],[19],[33] 6.50% [6],[19],[33] 6.50% [6],[19],[33] 6.50% [6],[19],[33] 6.50% [6],[19],[33] 6.50% [6],[19],[33] 6.50% [8],[18],[28] 6.50% [8],[18],[28] 6.50% [8],[18],[28] 6.50% [8],[18],[28] 6.50% [8],[18],[28] 6.50% [8],[18],[28] 6.50% [8],[18],[28]  
Base Rate Floor 0.80% [6],[19],[33] 0.80% [6],[19],[33] 0.80% [6],[19],[33] 0.80% [6],[19],[33] 0.80% [6],[19],[33] 0.80% [6],[19],[33] 0.80% [6],[19],[33] 0.80% [18],[28] 0.80% [18],[28] 0.80% [18],[28] 0.80% [18],[28] 0.80% [18],[28] 0.80% [18],[28] 0.80% [18],[28]  
Principal amount           $ 3.5 [13],[19],[33]             $ 3.5 [14],[18],[28]    
Amortized Cost $ 2,200,000 [19],[33]             $ 2,200,000 [18],[28]              
Fair Value $ (2,200,000) [4],[19],[33]             $ (2,200,000) [1],[18],[28]              
Investment, Identifier [Axis]: iNova Pharmaceuticals (Australia) Pty Limited, Pharmaceuticals, Biotechnology & Life Sciences | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Rate, Basis spread on variable rate 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base Rate Floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount           $ 34.2             $ 34.2    
Amortized Cost $ 22,500,000             $ 22,500,000              
Fair Value $ (22,300,000)             $ (22,600,000)              
[1] Fair value determined by the Company’s board of directors (see Note 8).
[2] Security may be an obligation of one or more entities affiliated with the named company
[3] Security may be an obligation of one or more entities affiliated with the named company.
[4] See Note 8 for additional information regarding the fair value of the Company's financial instruments
[5] The Company held this investment as of December 31, 2021 but it was not deemed to be an “affiliated person” of the portfolio company as of December 31, 2021. Transfers in or out have been presented at amortized cost.
[6] Certain variable rate securities in the Company’s portfolio bear interest at a rate determined by a publicly disclosed base rate plus a basis point spread. As of March 31, 2023, the three-month London Interbank Offered Rate, or LIBOR or “L”, was 5.19%, the Euro Interbank Offered Rate, or EURIBOR, was 3.04%, Canadian Dollar Offer Rate, or CDOR was 5.03%, the Australian Bank Bill Swap Bid Rate, or BBSY, or “B”, was 3.77%, the Reykjavik Interbank Offered Rate, or REIBOR or "R", was 8.25%, the Stockholm Interbank Offered Rate, or STIBOR or "SR", was 3.36%, the Sterling Interbank Offered Rate, or SONIA or "SA", was 4.18%, the Secured Overnight Financing Rate, or SOFR, was 4.91% and the U.S. Prime Lending Rate, or Prime, was 8.00%. PIK means paid-in-kind. PIK income accruals may be adjusted based on the fair value of the underlying investment. Variable rate securities with no floor rate use the respective benchmark rate in all cases.
[7] Security or portion thereof is pledged as collateral supporting the amounts outstanding under the Senior Secured Revolving Credit Facility (see Note 9).
[8] Certain variable rate securities in the Company’s portfolio bear interest at a rate determined by a publicly disclosed base rate plus a basis point spread. As of December 31, 2022, the three-month London Interbank Offered Rate, or LIBOR or “L”, was 4.77%, the Euro Interbank Offered Rate, or EURIBOR, was 2.13%, Canadian Dollar Offer Rate, or CDOR was 4.94%, the Bank Bill Swap Bid Rate, or BBSY was 3.32%, the Reykjavik Interbank Offered Rate, or REIBOR, was 6.55%, the Stockholm Interbank Offered Rate, or STIBOR, was 2.70%, the Sterling Overnight Index Average, or SONIA, was 3.43%, the Secured Overnight Financing Rate, or SOFR, was 4.59%, and the U.S. Prime Lending Rate, or Prime, was 7.50%. PIK means paid-in-kind. PIK income accruals may be adjusted based on the fair value of the underlying investment.
[9] Security or portion thereof held within Darby Creek LLC and is pledged as collateral supporting the amounts outstanding under a revolving credit facility with Deutsche Bank AG, New York Branch (see Note 9).
[10] Security or portion thereof held within Dunlap Funding LLC and is pledged as collateral supporting the amounts outstanding under a revolving credit facility with Deutsche Bank AG, New York Branch (see Note 9).
[11] Security or portion thereof is pledged as collateral supporting the amounts outstanding under the Senior Secured Revolving Credit Facility (see Note 9).
[12] Security or portion thereof was held within CCT Tokyo Funding LLC and was pledged as collateral supporting the amounts outstanding under the revolving credit facility with Sumitomo Mitsui Banking Corporation (see Note 9).
[13] Denominated in U.S dollars unless otherwise noted.
[14] Denominated in U.S. dollars unless otherwise noted.
[15] Security or portion thereof held within CCT Tokyo Funding LLC and pledged as collateral supporting the amounts outstanding under the revolving credit facility with Sumitomo Mitsui Banking Corporation (see Note 9).
[16] Security or portion thereof held within Darby Creek LLC and is pledged as collateral supporting the amounts outstanding under a revolving credit facility with Deutsche Bank AG, New York Branch (see Note 9).
[17] Security or portion thereof held within Dunlap Funding LLC and is pledged as collateral supporting the amounts outstanding under a revolving credit facility with Deutsche Bank AG, New York Branch (see Note 9)
[18] Security is an unfunded commitment. Reflects the stated spread at the time of commitment, but may not be the actual rate received upon funding.
[19] Security is an unfunded commitment. Reflects the stated spread at the time of commitment, but may not be the actual rate received upon funding
[20] Security or portion thereof held within Ambler Funding LLC and is pledged as collateral supporting the amounts outstanding under the revolving credit facility with Ally Bank (see Note 9).
[21] Security or portion thereof held within Meadowbrook Run LLC and is pledged as collateral supporting the amounts outstanding under a revolving credit facility with Morgan Stanley Senior Funding, Inc. (see Note 9).
[22] Security or portion thereof held within Ambler Funding LLC and is pledged as collateral supporting the amounts outstanding under the revolving credit facility with Ally Bank (see Note 9).
[23] Security or portion thereof held within Meadowbrook Run LLC and is pledged as collateral supporting the amounts outstanding under a revolving credit facility with Morgan Stanley Senior Funding, Inc. (see Note 9).
[24] Asset is on non-accrual status.
[25] Security held within IC Arches Investments LLC, a wholly-owned subsidiary of the Company.
[26] Security held within IC II Arches Investments, LLC, a wholly-owned subsidiary of the Company.
[27] Security is non-income producing.
[28] The investment is not a qualifying asset under the Investment Company Act of 1940, as amended. A business development company may not acquire any asset other than qualifying assets, unless, at the time the acquisition is made, qualifying assets represent at least 70% of the company’s total assets. As of December 31, 2022, 75.3% of the Company’s total assets represented qualifying assets.
[29] Asset is on non-accrual status.
[30] Security held within IC Arches Investments, LLC, a wholly-owned subsidiary of the Company.
[31] Security held within IC II Arches Investments, LLC, a wholly-owned subsidiary of the Company.
[32] Security is non-income producing.
[33] The investment, or portion of the investment is not a qualifying asset under the Investment Company Act of 1940, as amended. A business development company may not acquire any asset other than qualifying assets, unless, at the time the acquisition is made, qualifying assets represent at least 70% of the company’s total assets. As of March 31, 2023, 76.1% of the Company’s total assets represented qualifying assets.
[34] Under the Investment Company Act of 1940, as amended, the Company generally is deemed to “control” a portfolio company if it owns more than 25% of the portfolio company’s voting securities or it has the power to exercise control over the management or policies of such portfolio company. As of March 31, 2023, the Company held investments in portfolio companies of which it is deemed to be an "affiliated person" and deemed to "control". During the three months ended March 31, 2023, the Company disposed of investments in portfolio companies of which it was deemed to be an "affiliated person" and deemed to "control". The following table presents certain information with respect to investments in portfolio companies of which the Company was deemed to be an affiliated person and deemed to control as of March 31, 2023:
Portfolio Company
Fair Value at December 31, 2022
Gross Additions(1)
Gross Reductions(2)
Net Realized Gain (Loss)Net Change in Unrealized Appreciation (Depreciation)
Fair Value at March 31, 2023
Interest Income(3)
PIK Income(3)
Fee Income(3)
Dividend and Other Income(3)
Senior Secured Loans—First Lien
Tekfor HoldCo (formerly Amtek Global Technology Pte Ltd)$3.9 $— $— $— $0.1 $4.0 $— $— $— $— 
ATX Networks Corp 40.6 15.8 (0.8)— — 55.6 1.4 — — — 
HM Dunn Co Inc35.6 — (0.3)— — 35.3 1.0 — — — 
HM Dunn Co Inc— — — — — — — — — — 
NCI Inc28.1 0.8 — — 0.3 29.2 (0.3)0.9 — — 
Production Resource Group LLC 152.5 4.6 (0.3)— (0.6)156.2 4.8 2.1 — — 
Production Resource Group LLC 0.1 — — — — 0.1 — — — — 
Production Resource Group LLC 68.1 0.9 (0.7)— (0.5)67.8 1.9 0.5 — — 
Production Resource Group LLC31.3 0.3 (0.4)— (0.1)31.1 0.8 0.2 — — 
Warren Resources Inc18.6 0.2 — — (0.1)18.7 0.8 — — — 
Other Senior Secured Debt
 JW Aluminum Co 78.1 0.1 — — (1.2)77.0 2.0 — — — 
Subordinated Debt
ATX Networks Corp21.9 9.3 — — 0.1 31.3 0.3 0.6 — — 
Hilding Anders— — — — — — — — — — 
Hilding Anders— — — — — — 0.5 — — — 
Hilding Anders— — — — — — 0.1 — — — 
Asset Based Finance
 801 5th Ave, Seattle, Structure Mezzanine 58.9 0.1 — — (0.1)58.9 1.2 0.4 — — 
 801 5th Ave, Seattle, Private Equity 6.3 — — — (1.1)5.2 — — — — 
 Avenue One PropCo, Private Equity 31.0 4.1 — — (0.6)34.5 — — — — 
 Avida Holding AB, Common Stock 42.6 — — — (7.1)35.5 — — — — 
 Kilter Finance, Preferred Stock 99.5 — — — (0.1)99.4 3.7 — — — 
 Kilter Finance, Private Equity 0.5 — — — — 0.5 — — — — 
KKR Altitude II Offshore Aggregator LP, Partnership Interest44.4 4.6 — — 0.8 49.8 — — — — 
 KKR Rocket Loans Aggregator LLC, Partnership Interest 4.3 9.9 — — (0.3)13.9 — — — 0.3 
 My Community Homes PropCo 2, Private Equity 79.0 — (2.5)— 4.0 80.5 — — — — 
 Prime St LLC, Private Equity — — (0.1)— 0.1 — — — — — 
 Prime St LLC, Structured Mezzanine 43.5 — — — (3.9)39.6 0.8 0.8 — — 
Roemanu LLC (FKA Toorak Capital Partners LLC), Private Equity 261.2 0.1 — — (6.5)254.8 — — — 5.1 
Credit Opportunities Partners JV, LLC
Portfolio Company
Fair Value at December 31, 2022
Gross Additions(1)
Gross Reductions(2)
Net Realized Gain (Loss)Net Change in Unrealized Appreciation (Depreciation)
Fair Value at March 31, 2023
Interest Income(3)
PIK Income(3)
Fee Income(3)
Dividend and Other Income(3)
Credit Opportunities Partners JV, LLC$1,428.3 $— $— $— $(31.7)$1,396.6 $— $— $— $57.5 
Equity/Other
Amtek Global Technology Pte Ltd, Common Stock — — — — — — — — — — 
Amtek Global Technology Pte Ltd, Ordinary Shares — — — — — — — — — — 
Amtek Global Technology Pte Ltd, Private Equity — — — — — — — — — — 
ATX Networks Corp, Common Stock 29.2 8.2 — — 1.1 38.5 — — — — 
ATX Networks Corp, Class B-1 Common Stock5.0 — — — — 5.0 — — — — 
ATX Networks Corp, Class B-2 Common Stock9.0 — — — — 9.0 — — — — 
Hilding Anders, Class A Common Stock — — — — — — — — — — 
Hilding Anders, Class B Common Stock — — — — — — — — — — 
Hilding Anders, Class C Common Stock — — — — — — — — — — 
Hilding Anders, Equity Options — — — — — — — — — — 
HM Dunn Co Inc, Preferred Stock, Series A 16.9 — — — (0.3)16.6 — — — — 
HM Dunn Co Inc, Preferred Stock, Series B — — — — — — — — — — 
JW Aluminum Co, Common Stock 2.4 — — — — 2.4 — — — — 
JW Aluminum Co, Preferred Stock 112.5 4.5 — — 30.9 147.9 0.1 4.5 — — 
NCI Inc, Class A-1 Common Stock— — — — — — — — — — 
NCI Inc, Class B-1 Common Stock— — — — — — — — — — 
NCI Inc, Class C Common Stock20.2 — — — (1.1)19.1 — — — — 
NCI Inc, Class I-1 Common Stock— — — — — — — — — — 
PRG III LLC, Preferred Stock, Series A PIK105.7 — — — 33.8 139.5 — — — — 
PRG III LLC, Preferred Stock, Series B PIK— — — — — — — — — — 
Warren Resources Inc, Common Stock 29.2 — — — (5.7)23.5 — — — — 
Total$2,908.4 $63.5 $(5.1)$— $10.2 $2,977.0 $19.1 $10.0 $— $62.9 
______________
(1)Gross additions include increases in the cost basis of investments resulting from new portfolio investments, PIK interest, the amortization of unearned income, the exchange of one or more existing securities for one or more new securities and the movement of an existing portfolio company into this category from a different category.
(2)Gross reductions include decreases in the cost basis of investments resulting from principal collections related to investment repayments or sales, the exchange of one or more existing securities for one or more new securities and the movement of an existing portfolio company out of this category into a different category.
(3)Interest, PIK, fee and dividend income presented for the full three months ended March 31, 2023.
(4)The Company held this investment as of March 31, 2023 but it was not deemed to be an “control” of the portfolio company as of March 31, 2023.
[35] Under the Investment Company Act of 1940, as amended, the Company generally is deemed to “control” a portfolio company if it owns more than 25% of the portfolio company’s voting securities or it has the power to exercise control over the management or policies of such portfolio company. As of December 31, 2022, the Company held investments in one portfolio company of which it is deemed to be an “affiliated person” and deemed to “control”. During the year ended December 31, 2022, the Company disposed of investments in one portfolio of which it was deemed to be an "affiliated person" and deemed to "control". The following table presents certain information with respect to investments in portfolio companies of which the Company was deemed to be an affiliated person and deemed to control for the year ended December 31, 2022:
Portfolio CompanyFair Value at December 31, 2021
Gross Additions(1)
Gross Reductions(2)
Net Realized Gain (Loss)Net Change in Unrealized Appreciation (Depreciation)Fair Value at December 31, 2022
Interest Income(3)
PIK Income(3)
Fee Income(3)
Dividend Income(3)
Senior Secured Loans—First Lien
Amtek Global Technology Pte Ltd$34.8 $— $(24.3)$(4.3)$(2.3)$3.9 $— $— $— $— 
ATX Networks Corp46.8 0.4 (6.6)— — 40.6 3.2 1.0 — — 
HM Dunn Co Inc33.6 2.0 — — — 35.6 0.8 2.1 — — 
HM Dunn Co Inc2.0 — (2.0)— — — — — — — 
NCI Inc— 79.1 (21.9)(28.5)(0.6)28.1 6.5 0.4 — — 
One Call Care Management Inc(5)
5.0 — (4.7)— (0.3)— — — — — 
Production Resource Group LLC133.3 19.3 (0.3)— 0.2 152.5 12.9 8.0 — — 
Production Resource Group LLC0.1 — — — — 0.1 — — — — 
Production Resource Group LLC64.4 3.7 (0.6)— 0.6 68.1 6.4 2.0 — — 
Portfolio CompanyFair Value at December 31, 2021
Gross Additions(1)
Gross Reductions(2)
Net Realized Gain (Loss)Net Change in Unrealized Appreciation (Depreciation)Fair Value at December 31, 2022
Interest Income(3)
PIK Income(3)
Fee Income(3)
Dividend Income(3)
Production Resource Group LLC20.2 11.1 (0.3)— 0.3 31.3 — 0.9 — — 
Warren Resources Inc18.7 0.6 (0.2)— (0.5)18.6 2.5 0.2 — — 
Senior Secured Loans—Second Lien
Amtek Global Technology Pte Ltd— — — (39.1)39.1 — — — — — 
Other Senior Secured Debt
JW Aluminum Co81.0 0.2 — — (3.1)78.1 8.0 — — — 
One Call Care Management Inc(5)
23.5 — (21.6)— (1.9)— — — — — 
Subordinated Debt
ATX Networks Corp7.1 3.6 — — 11.2 21.9 1.6 1.5 — — 
Hilding Anders46.6 — — — (46.6)— — — — — 
Hilding Anders— — — — — — 0.3 — — — 
Hilding Anders— — — — — — 0.1 — — — 
Asset Based Finance
801 5th Ave, Seattle, Structure Mezzanine57.2 1.9 — — (0.2)58.9 4.7 1.7 — — 
801 5th Ave, Seattle, Private Equity23.1 — (0.1)— (16.7)6.3 — — — — 
Avenue One PropCo, Private Equity— 46.3 (16.2)— 0.9 31.0 — — — — 
Avida Holding AB, Common Stock52.3 — — — (9.7)42.6 — — — — 
Kilter Finance, Preferred Stock36.1 87.3 (24.0)0.7 (0.6)99.5 7.4 1.9 — — 
Kilter Finance, Private Equity0.5 — — — — 0.5 — — — — 
KKR Altitude II Offshore Aggregator LP, Partnership Interest— 44.4 — — 44.4 — — — — 
KKR Rocket Loans Aggregator LLC, Partnership Interest1.4 2.9 — — — 4.3 — — — 1.3 
My Community Homes SFR PropCo 2, Private Equity33.0 157.0 (105.7)— (5.3)79.0 — — — — 
Prime St LLC, Private Equity9.1 — (0.3)— (8.8)— — — — — 
Prime St LLC, Structured Mezzanine52.4 3.3 — — (12.2)43.5 3.2 3.1 — — 
Toorak Capital Funding LLC, Membership Interest1.7 — (1.7)(0.2)0.2 — — — — 0.3 
Roemanu LLC (FKA Toorak Capital Partners LLC), Private Equity199.3 78.3 — — (16.4)261.2 — — — 18.8 
Roemanu LLC (FKA Toorak Capital Partners LLC), Structured Mezzanine22.0 32.0 (54.0)— — — — 0.6 — — 
Credit Opportunities Partners JV, LLC
Credit Opportunities Partners JV, LLC1,396.2 175.0 — — (142.9)1,428.3 — — — 208.3 
Equity/Other
Amtek Global Technology Pte Ltd, Common Stock— — — — — — — — — — 
Amtek Global Technology Pte Ltd, Ordinary Shares— — — — — — — — — — 
Amtek Global Technology Pte Ltd, Private Equity— — — — — — — — — — 
ATX Networks Corp, Common Stock— 1.7 — — 27.5 29.2 — — — — 
ATX Networks Corp, Class B-1 Common Stock— 5.0 — — — 5.0 — — — — 
ATX Networks Corp, Class B-2 Common Stock— 4.0 — — 5.0 9.0 — — — — 
Hilding Anders, Class A Common Stock— — — — — — — — — — 
Hilding Anders, Class B Common Stock— — — — — — — — — — 
Portfolio CompanyFair Value at December 31, 2021
Gross Additions(1)
Gross Reductions(2)
Net Realized Gain (Loss)Net Change in Unrealized Appreciation (Depreciation)Fair Value at December 31, 2022
Interest Income(3)
PIK Income(3)
Fee Income(3)
Dividend Income(3)
Hilding Anders, Class C Common Stock— — — — — — — — — — 
Hilding Anders, Equity Options— — — — — — — — — — 
HM Dunn Co Inc, Preferred Stock, Series A7.1 — — — 9.8 16.9 — — — — 
HM Dunn Co Inc, Preferred Stock, Series B— — — — — — — — — — 
JW Aluminum Co, Common Stock— — — — 2.4 2.4 — — — — 
JW Aluminum Co, Preferred Stock122.6 22.2 — — (32.3)112.5 0.6 19.7 — — 
NCI Inc, Class A-1 Common Stock(4)
— — — — — — — — — — 
NCI Inc, Class B-1 Common Stock(4)
— — — — — — — — — — 
NCI Inc, Class C Common Stock(4)
— 20.2 — — — 20.2 — — — — 
NCI Inc, Class I-1 Common Stock(4)
— — — — — — — — — — 
One Call Care Management Inc, Common Stock(5)
2.4 — (2.1)— (0.3)— — — — — 
One Call Care Management Inc, Preferred Stock A(5)
26.1 — (22.8)— (3.3)— — — — — 
One Call Care Management Inc, Preferred Stock B(5)
9.2 — (8.0)— (1.2)— — — — — 
PRG III LLC, Preferred Stock, Series A PIK17.4 — — — 88.3 105.7 — — — — 
PRG III LLC, Preferred Stock, Series B PIK— — — — — — — — — — 
Sound United LLC, Common Stock77.5 — (17.3)— (60.2)— — — — — 
Warren Resources Inc, Common Stock20.4 — — — 8.8 29.2 — — — — 
Total$2,684.1 $801.5 $(334.7)$(71.4)$(171.1)$2,908.4 $58.2 $43.1 $— $228.7 
______________
(1)Gross additions include increases in the cost basis of investments resulting from new portfolio investments, PIK interest, the amortization of unearned income, the exchange of one or more existing securities for one or more new securities and the movement of an existing portfolio company into this category from a different category.
(2)Gross reductions include decreases in the cost basis of investments resulting from principal collections related to investment repayments or sales, the exchange of one or more existing securities for one or more new securities and the movement of an existing portfolio company out of this category into a different category.
(3)Interest, PIK, fee and dividend income presented for the full year ended December 31, 2022.
(4)The Company held this investment as of December 31, 2021 but it was not deemed to be an “control” of the portfolio company as of December 31, 2021. Transfers in or out have been presented at amortized cost.
[36] Security or portion thereof held within Juniata River LLC and is pledged as collateral supporting the amounts outstanding under a term loan credit facility with JPMorgan Chase Bank, N.A. (see Note 9).
[37] Security or portion thereof held within Juniata River LLC and is pledged as collateral supporting the amounts outstanding under a term loan credit facility with JPMorgan Chase Bank, N.A. (see Note 9).
[38] Position or portion thereof unsettled as of December 31, 2022.
[39] Security is classified as Level 1 or Level 2 in the Company's fair value hierarchy (see Note 8).
[40] Security is classified as Level 1 or 2 in the Company's fair value hierarchy (see Note 8).
[41] Security or portion thereof held within FS KKR MM CLO 1 LLC (see Note 9).
[42] Security or portion thereof was held within FSK CLO as of December 31, 2022.
[43] Under the Investment Company Act of 1940, as amended, the Company generally is deemed to be an “affiliated person” of a portfolio company if it owns 5% or more of the portfolio company’s voting securities and generally is deemed to “control” a portfolio company if it owns more than 25% of the portfolio company’s voting securities or it has the power to exercise control over the management or policies of such portfolio company. As of March 31, 2023, the Company held investments in portfolio companies of which it is deemed to be an “affiliated person” but is not deemed to “control”. The following table presents certain information with respect to investments in portfolio companies of which the Company was deemed to be an affiliated person as of March 31, 2023:
Portfolio Company
Fair Value at December 31, 2022
Gross Additions(1)
Gross Reductions(2)
Net Realized Gain (Loss)Net Change in Unrealized Appreciation (Depreciation)
Fair Value at March 31, 2023
Interest Income(3)
PIK Income(3)
Fee Income(3)
Dividend and Other Income(3)
Senior Secured Loans—First Lien
Affordable Care Inc$53.1 $2.9 $(1.5)$— $0.7 $55.2 $1.3 $0.2 $— $— 
Belk Inc8.8 0.9 (1.3)0.2 3.9 12.5 — — — — 
Belk Inc19.4 — — — (0.7)18.7 0.7 — — — 
Constellis Holdings LLC15.0 0.1 — — (0.1)15.0 0.6 — — — 
Sungard Availability Services Capital Inc(4)
0.5 — (5.8)— 5.3 — — — — — 
Sungard Availability Services Capital Inc(4)
2.0 — (2.0)— — — — — — — 
ThermaSys Corp8.6 — — — (2.5)6.1 — — — — 
Senior Secured Loans—Second Lien
Belk Inc 3.3 — — — (3.3)— — — — — 
Constellis Holdings LLC 13.5 — — — — 13.5 0.6 — — — 
Sungard Availability Services Capital Inc(4)
— — (13.5)— 13.5 — — — — — 
Asset Based Finance
Home Partners JV 2, Structured Mezzanine10.2 0.3 — — — 10.5 — 0.3 — — 
Home Partners JV 2, Private Equity 0.2 — — — — 0.2 — — — — 
Home Partners JV 2, Private Equity 5.0 — — — (0.5)4.5 — — — — 
Equity/Other
Affordable Care Inc, Preferred Stock 49.9 — — — (0.8)49.1 — 1.4 — — 
athenahealth Inc, Preferred Stock 231.2 — — — (0.5)230.7 — 7.2 — — 
Belk Inc, Common Stock — — — — — — — — — — 
Borden (New Dairy Opco), Common Stock 4.8 — — — 1.9 6.7 — — — — 
Constellis Holdings LLC, Private Equity 6.3 — — — (2.4)3.9 — — — — 
Fronton BV, Common Stock 1.0 — — — 0.2 1.2 — — — — 
Proserv Acquisition LLC, Class A Common Units 1.1 — — — 0.8 1.9 — — — — 
Proserv Acquisition LLC, Class A Preferred Units 9.5 — — — — 9.5 — — — — 
ThermaSys Corp, Common Stock — — — — — — — — — — 
ThermaSys Corp, Preferred Stock — — — — — — — — — — 
Total$443.4 $4.2 $(24.1)$0.2 $15.5 $439.2 $3.2 $9.1 $— $— 
______________
(1)Gross additions include increases in the cost basis of investments resulting from new portfolio investments, PIK interest, the amortization of unearned income, the exchange of one or more existing securities for one or more new securities and the movement of an existing portfolio company into this category from a different category.
(2)Gross reductions include decreases in the cost basis of investments resulting from principal collections related to investment repayments or sales, the exchange of one or more existing securities for one or more new securities and the movement of an existing portfolio company out of this category into a different category.
(3)Interest, PIK, fee and dividend income presented for the full three months ended March 31, 2023.
(4)The Company held this investment as of March 31, 2023 but it was not deemed to be an “affiliated person” of the portfolio company as of March 31, 2023.
[44] Under the Investment Company Act of 1940, as amended, the Company generally is deemed to be an “affiliated person” of a portfolio company if it owns 5% or more of the portfolio company’s voting securities and generally is deemed to “control” a portfolio company if it owns more than 25% of the portfolio company’s voting securities or it has the power to exercise control over the management or policies of such portfolio company. As of December 31, 2022, the Company held investments in portfolio companies of which it is deemed to be an “affiliated person” but is not deemed to “control”. The following table presents certain information with respect to investments in portfolio companies of which the Company was deemed to be an affiliated person for the year ended December 31, 2022:
Portfolio CompanyFair Value at December 31, 2021
Gross Additions(1)
Gross Reductions(2)
Net Realized Gain (Loss)Net Change in Unrealized Appreciation (Depreciation)Fair Value at December 31, 2022
Interest Income(3)
PIK Income(3)
Fee Income(3)
Dividend Income(3)
Senior Secured Loans—First Lien
Affordable Care Inc$— $— $— $— $— $— $— $— $— $— 
Affordable Care Inc59.9 16.2 (21.4)— (1.6)53.1 4.1 — 0.2 — 
athenahealth Inc— 6.8 (6.1)(0.7)— — 0.2 — 0.2 — 
Belk Inc49.2 4.7 (2.2)(0.2)(42.7)8.8 3.7 2.7 — — 
Belk Inc21.9 0.1 — — (2.6)19.4 2.2 — — — 
Borden (New Dairy Opco)9.0 — (9.0)0.6 (0.6)— 0.1 — 0.3 — 
Borden (New Dairy Opco)42.0 0.1 (42.0)1.7 (1.8)— 0.9 — 1.3 — 
Borden Dairy Co— — — (25.4)25.4 — — — — — 
Constellis Holdings LLC15.0 0.4 — — (0.4)15.0 1.8 — — — 
Fairway Group Holdings Corp0.7 — — (1.0)0.3 — — — — — 
Portfolio CompanyFair Value at December 31, 2021
Gross Additions(1)
Gross Reductions(2)
Net Realized Gain (Loss)Net Change in Unrealized Appreciation (Depreciation)Fair Value at December 31, 2022
Interest Income(3)
PIK Income(3)
Fee Income(3)
Dividend Income(3)
Fairway Group Holdings Corp— — — — — — — — — — 
Micronics Filtration Holdings Inc51.0 5.7 (51.7)— (5.0)— 0.2 0.3 — — 
Petroplex Acidizing Inc9.7 — (16.7)(5.3)12.3 — — — — — 
Sorenson Communications LLC(4)
60.1 — (56.9)— (3.2)— — — — — 
Sungard Availability Services Capital Inc(4)
6.0 0.1 — — (5.6)0.5 — — — — 
Sungard Availability Services Capital Inc(4)
— 4.5 (2.5)— — 2.0 0.3 0.2 0.3 — 
ThermaSys Corp3.5 — — — 5.1 8.6 — — — — 
Senior Secured Loans—Second Lien
Belk Inc6.7 — — — (3.4)3.3 — — — — 
Constellis Holdings LLC12.0 0.3 — — 1.2 13.5 2.0 — — — 
Fairway Group Holdings Corp— — — — — — — — — — 
 Sungard Availability Services Capital Inc(4)
8.3 — (0.2)— (8.1)— — — — — 
Subordinated Debt
athenahealth Inc— 5.5 (4.7)(0.8)— — 0.1 — — — 
Asset Based Finance
Home Partners JV, Structured Mezzanine90.4 7.9 (98.1)4.6 (4.8)— 0.3 7.5 — — 
Home Partners JV, Private Equity9.4 — (11.8)6.4 (4.0)— — — — 0.7 
Home Partners JV, Common Stock80.6 — (101.0)53.4 (33.0)— — — — 4.3 
Home Partners JV 2, Structured Mezzanine3.5 6.7 — 0.1 (0.1)10.2 — 0.7 — — 
Home Partners JV 2, Private Equity0.1 0.1 — — — 0.2 — — — — 
Home Partners JV 2, Private Equity1.6 2.9 — — 0.5 5.0 — — — — 
Jet Edge International LLC, Preferred Stock16.8 — (30.1)9.2 4.1 — 0.7 — — — 
Jet Edge International LLC, Warrant4.5 — (13.5)13.5 (4.5)— — — — 1.5 
Jet Edge International LLC, Term Loan75.6 — (75.9)— 0.3 — 11.6 2.3 3.3 — 
Orchard Marine Limited, Class B Common Stock— — — (3.1)3.1 — — — — — 
Orchard Marine Limited, Series A Preferred Stock64.6 0.1 (66.0)3.9 (2.6)— — — — — 
Equity/Other
Affordable Care Inc, Common Stock52.1 — — — (2.2)49.9 — 5.5 — — 
athenahealth Inc, Preferred Stock— 311.3 (47.5)(1.6)(31.0)231.2 — 29.0— — 
Belk Inc, Common Stock— — — — — — — — — — 
Borden (New Dairy Opco), Common Stock7.7 — — — (2.9)4.8 — — — — 
Constellis Holdings LLC, Private Equity0.2 — — — 6.1 6.3 — — — — 
Fairway Group Holdings Corp, Common Stock— — — — — — — — — — 
Fronton BV, Common Stock1.4 — — — (0.4)1.0 — — — — 
Micronics Filtration Holdings Inc, Common Stock— — (0.1)(0.5)0.6 — — — — — 
Micronics Filtration Holdings Inc, Preferred Stock, Series A0.1 — — (0.6)0.5 — — — — — 
Micronics Filtration Holdings Inc, Preferred Stock, Series B0.4 — (0.4)0.2 (0.2)— — — — — 
Micronics Filtration Holdings Inc, Preferred Stock, Series B PIK11.9 — (11.9)11.9 (11.9)— — — — — 
Portfolio CompanyFair Value at December 31, 2021
Gross Additions(1)
Gross Reductions(2)
Net Realized Gain (Loss)Net Change in Unrealized Appreciation (Depreciation)Fair Value at December 31, 2022
Interest Income(3)
PIK Income(3)
Fee Income(3)
Dividend Income(3)
Micronics Filtration Holdings Inc, Preferred Stock, Series C PIK6.2 — (6.2)6.2 (6.2)— — — — — 
Petroplex Acidizing Inc, Preferred Stock A— — — (4.9)4.9 — — — — — 
Petroplex Acidizing Inc, Warrant— — — — — — — — — — 
Proserv Acquisition LLC, Class A Common Units0.1 0.1 — — 0.9 1.1 — — — — 
Proserv Acquisition LLC, Class A Preferred Units9.3 — — — 0.2 9.5 — — — — 
 Sorenson Communications LLC, Common Stock(4)
67.5 — (65.4)22.9 (25.0)— — — — — 
 Sungard Availability Services Capital Inc, Common Stock(4)
— — — (6.9)6.9 — — — — — 
ThermaSys Corp, Common Stock— — — — — — — — — — 
ThermaSys Corp, Preferred Stock— — — — — — — — — — 
Total$859.0 $373.5 $(741.3)$83.6 $(131.4)$443.4 $28.2 $48.2 $5.6 $6.5 
______________
(1)Gross additions include increases in the cost basis of investments resulting from new portfolio investments, PIK interest, the amortization of unearned income, the exchange of one or more existing securities for one or more new securities and the movement of an existing portfolio company into this category from a different category.
(2)Gross reductions include decreases in the cost basis of investments resulting from principal collections related to investment repayments or sales, the exchange of one or more existing securities for one or more new securities and the movement of an existing portfolio company out of this category into a different category.
(3)Interest, PIK, fee and dividend income presented for the full year ended December 31, 2022.
(4)The Company held this investment as of December 31, 2021 but it was not deemed to be an “affiliated person” of the portfolio company as of December 31, 2021. Transfers in or out have been presented at amortized cost.
[45] Security or portion thereof held within CCT Dublin Funding Limited.
[46] Security or portion thereof was held within CCT Dublin Funding Limited
[47] Security held within CCT Holdings II, LLC, a wholly-owned subsidiary of the Company
[48] Security held within CCT Holdings II, LLC, a wholly-owned subsidiary of the Company.
[49] Security held within IC American Energy Investments, Inc., a wholly-owned subsidiary of the Company.
[50] Security held within IC American Energy Investments, Inc., a wholly-owned subsidiary of the Company.
[51] Security held within FSIC II Investments, Inc., a wholly-owned subsidiary of the Company.
[52] Security held within FSIC II Investments, Inc., a wholly-owned subsidiary of the Company.
[53] Security or portion thereof held within Race Street Funding LLC. Security is available as collateral to support the amounts outstanding under the Senior Secured Revolving Credit Facility (see Note 9).
[54] Security or portion thereof held within Race Street Funding LLC. Security is available as collateral supporting the amounts outstanding under the Senior Secured Revolving Credit Facility (see Note 9).
[55] Security or portion thereof held within Cobbs Creek LLC and is pledged as collateral supporting the amounts outstanding under the senior secured revolving credit facility (see Note 9).
[56] Security or portion thereof held within Cobbs Creek LLC and is pledged as collateral supporting the amounts outstanding under the senior secured revolving credit facility (see Note 9).
[57] Security held within FSIC Investments, Inc., a wholly-owned subsidiary of the Company.
[58] Security held within FSIC Investments, Inc., a wholly-owned subsidiary of the Company.
[59] The Company held this investment as of December 31, 2022 but it was not deemed to be an “control” of the portfolio company as of December 31, 2022. Transfers in or out have been presented at amortized cost.
[60] The Company held this investment as of March 31, 2023 but it was not deemed to be an “affiliated person” of the portfolio company as of March 31, 2023.
[61] Position or portion thereof unsettled as of March 31, 2023.