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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 219.30% 219.30% 219.30% 219.30% 219.30% 219.30% 219.30% 208.30% 208.30% 208.30% 208.30% 208.30% 208.30% 208.30%  
Amortized cost $ 16,314.1             $ 16,056.7              
Fair value $ (15,377.3) [1]             $ (16,101.5) [2]              
Liabilities in excess of other assets percentage 119.30% 119.30% 119.30% 119.30% 119.30% 119.30% 119.30% 108.30% 108.30% 108.30% 108.30% 108.30% 108.30% 108.30%  
Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Percent of net assets 218.50% 218.50% 218.50% 218.50% 218.50% 218.50% 218.50% 204.30% 204.30% 204.30% 204.30% 204.30% 204.30% 204.30%  
Amortized cost $ 3,755.5             $ 3,206.2              
Fair value (3,562.9)             (3,260.0)              
Foreign currency forward contracts $ 11.9             $ (6.7)              
Liabilities in excess of other assets percentage 0.70% 0.70% 0.70% 0.70% 0.70% 0.70% 0.70% (0.40%) (0.40%) (0.40%) (0.40%) (0.40%) (0.40%) (0.40%)  
London Interbank Offered Rate (LIBOR)                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               0.21% 0.21% 0.21% 0.21% 0.21% 0.21% 0.21%  
Variable rate 4.77% 4.77% 4.77% 4.77% 4.77% 4.77% 4.77%                
London Interbank Offered Rate (LIBOR) | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 4.77% 4.77% 4.77% 4.77% 4.77% 4.77% 4.77% 0.21% 0.21% 0.21% 0.21% 0.21% 0.21% 0.21%  
EURIBOR | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 2.13% 2.13% 2.13% 2.13% 2.13% 2.13% 2.13% (0.57%) (0.57%) (0.57%) (0.57%) (0.57%) (0.57%) (0.57%)  
CDOR                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 4.94% 4.94% 4.94% 4.94% 4.94% 4.94% 4.94% 0.48% 0.48% 0.48% 0.48% 0.48% 0.48% 0.48%  
CDOR | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 4.94% 4.94% 4.94% 4.94% 4.94% 4.94% 4.94% 0.48% 0.48% 0.48% 0.48% 0.48% 0.48% 0.48%  
BBSY                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 3.32% 3.32% 3.32% 3.32% 3.32% 3.32% 3.32% 0.12% 0.12% 0.12% 0.12% 0.12% 0.12% 0.12%  
BBSY | 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% 0.12% 0.12% 0.12% 0.12% 0.12% 0.12% 0.12%  
REIBOR                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 6.55% 6.55% 6.55% 6.55% 6.55% 6.55% 6.55% 2.65% 2.65% 2.65% 2.65% 2.65% 2.65% 2.65%  
REIBOR | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 6.55% 6.55% 6.55% 6.55% 6.55% 6.55% 6.55% 2.65% 2.65% 2.65% 2.65% 2.65% 2.65% 2.65%  
STIBOR                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 2.70% 2.70% 2.70% 2.70% 2.70% 2.70% 2.70% (0.05%) (0.05%) (0.05%) (0.05%) (0.05%) (0.05%) (0.05%)  
STIBOR | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 2.70% 2.70% 2.70% 2.70% 2.70% 2.70% 2.70% (0.05%) (0.05%) (0.05%) (0.05%) (0.05%) (0.05%) (0.05%)  
SONIA | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 3.43% 3.43% 3.43% 3.43% 3.43% 3.43% 3.43% 0.19% 0.19% 0.19% 0.19% 0.19% 0.19% 0.19%  
SOFR                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 4.59% 4.59% 4.59% 4.59% 4.59% 4.59% 4.59% 0.05% 0.05% 0.05% 0.05% 0.05% 0.05% 0.05%  
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%                
Pime                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 3.25% 3.25% 3.25% 3.25% 3.25% 3.25% 3.25%  
Pime | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 3.25% 3.25% 3.25% 3.25% 3.25% 3.25% 3.25%  
Senior Secured Loans—First Lien                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Percent of net assets 132.30% 132.30% 132.30% 132.30% 132.30% 132.30% 132.30% 126.30% 126.30% 126.30% 126.30% 126.30% 126.30% 126.30%  
Amortized cost $ 9,607.5             $ 9,695.1              
Fair value $ (9,278.4) [3]             $ (9,765.0)              
Senior Secured Loans—First Lien | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Percent of net assets 148.10% 148.10% 148.10% 148.10% 148.10% 148.10% 148.10% 135.20% 135.20% 135.20% 135.20% 135.20% 135.20% 135.20%  
Amortized cost $ 2,519.5             $ 2,134.5              
Fair value (2,414.9)             (2,157.5)              
Senior Secured Loans—First Lien                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Amortized cost 10,515.6             11,165.5              
Fair value (10,186.5) [3]             (11,236.1) [2]              
Senior Secured Loans—First Lien | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Amortized cost 2,522.8             2,136.4              
Fair value (2,418.2)             (2,159.4)              
Unfunded - Senior Secured Loans - First Lien                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Amortized cost 908.1             1,470.4              
Fair value (908.1) [3]             (1,470.4) [2]              
Unfunded - Senior Secured Loans - First Lien | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Amortized cost 3.3             1.9              
Fair value $ (3.3)             $ (1.9)              
Senior Secured Loans—Second Lien                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Percent of net assets 17.00% 17.00% 17.00% 17.00% 17.00% 17.00% 17.00% 20.10% 20.10% 20.10% 20.10% 20.10% 20.10% 20.10%  
Amortized cost $ 1,299.2             $ 1,564.4              
Fair value $ (1,194.5) [3]             $ (1,556.5) [2]              
Senior Secured Loans—Second Lien | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Percent of net assets 23.60% 23.60% 23.60% 23.60% 23.60% 23.60% 23.60% 31.50% 31.50% 31.50% 31.50% 31.50% 31.50% 31.50%  
Amortized cost $ 459.1             $ 491.3              
Fair value (385.0)             (502.4)              
Other Senior Secured Debt                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Amortized cost 152.0             149.0              
Fair value $ (110.0)             $ (120.0)              
Other Senior Secured 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% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50%  
Amortized cost $ 25.0             $ 22.9              
Fair value $ (20.9)             $ (23.5)              
Subordinated Debt                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Percent of net assets 3.80% 3.80% 3.80% 3.80% 3.80% 3.80% 3.80% 1.40% 1.40% 1.40% 1.40% 1.40% 1.40% 1.40%  
Amortized cost $ 383.9             $ 188.3              
Fair value $ (265.0) [3]             $ (111.3) [2]              
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%                
Amortized cost $ 21.0                            
Fair value $ (21.1)                            
Asset Based Finance                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Percent of net assets 27.10% 27.10% 27.10% 27.10% 27.10% 27.10% 27.10% 29.10% 29.10% 29.10% 29.10% 29.10% 29.10% 29.10%  
Amortized cost $ 2,023.6             $ 2,132.0              
Fair value $ (1,902.5) [3]             $ (2,245.0) [2]              
Asset Based Finance | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Percent of net assets 33.20% 33.20% 33.20% 33.20% 33.20% 33.20% 33.20% 31.00% 31.00% 31.00% 31.00% 31.00% 31.00% 31.00%  
Amortized cost $ 550.5             $ 473.6              
Fair value (542.0)             (494.5)              
Equity/Other                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Amortized cost 1,276.0             932.0              
Fair value $ (1,199.0)             $ (907.0)              
Equity/Other | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Percent of net assets 11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 5.10% 5.10% 5.10% 5.10% 5.10% 5.10% 5.10%  
Amortized cost $ 180.4             $ 83.9              
Fair value $ (179.0)             $ (82.1)              
Investment, Identifier [Axis]: 3Pillar Global Inc, Senior Secured Loans—First Lien, Revolving Credit Facility, Software & Services, November, 23 2026                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 9.2              
Amortized cost [5]               9.2              
Fair value [2],[5]               $ (9.1)              
Investment, Identifier [Axis]: 3Pillar Global Inc, Senior Secured Loans—First Lien, Revolving Credit Facility, Software & Services, November, 23 2027 - 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [7],[8],[9],[10]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [8],[9],[11]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[8],[9],[11]               $ 96.3              
Amortized cost [8],[9],[11]               95.3              
Fair value [2],[8],[9],[11]               $ (95.3)              
Investment, Identifier [Axis]: 3Pillar Global Inc, Senior Secured Loans—First Lien, Revolving Credit Facility, Software & Services, November, 23 2027 - 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 30.6              
Amortized cost [5]               30.6              
Fair value [2],[5]               (30.2)              
Investment, Identifier [Axis]: 3Pillar Global Inc, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[14],[15],[16] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [13],[14],[15],[16] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[14],[15],[16],[17] $ 101.0                            
Amortized cost [13],[14],[15],[16] 100.2                            
Fair value [3],[13],[14],[15],[16] $ (96.7)                            
Investment, Identifier [Axis]: 3Pillar Global Inc, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 9.2                            
Amortized cost [4] 9.2                            
Fair value [3],[4] $ (8.8)                            
Investment, Identifier [Axis]: 3Pillar Global Inc, Software & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 24.9                            
Amortized cost [4] 24.9                            
Fair value [3],[4] $ (23.8)                            
Investment, Identifier [Axis]: 48Forty Solutions LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 19.4                            
Amortized cost 19.2                            
Fair value $ (18.8)                            
Investment, Identifier [Axis]: 48Forty Solutions LLC, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[14],[15],[18],[19] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [13],[14],[15],[18],[19] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[14],[15],[17],[18],[19] $ 182.7                            
Amortized cost [13],[14],[15],[18],[19] 181.2                            
Fair value [3],[13],[14],[15],[18],[19] $ (177.8)                            
Investment, Identifier [Axis]: 48Forty Solutions LLC, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 10.6                            
Amortized cost [4] 10.6                            
Fair value [3],[4] (10.3)                            
Investment, Identifier [Axis]: 5 Arch Income Fund 2 LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [6],[20],[21],[22],[23],[24]               111.1              
Amortized cost [20],[21],[22],[23],[24]               81.3              
Fair value [2],[20],[21],[22],[23],[24]               (78.3)              
Investment, Identifier [Axis]: 5 Arch Income Fund 2 LLC, Diversified Financials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [17],[25],[26],[27],[28],[29] 95.5                            
Amortized cost [25],[26],[27],[28],[29] 69.9                            
Fair value [3],[25],[26],[27],[28],[29] (52.5)                            
Investment, Identifier [Axis]: 801 5th Ave, Seattle, Private Equity                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (6.3)             $ (23.1)             $ (10.3)
Investment, Identifier [Axis]: 801 5th Ave, Seattle, Private Equity, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 8,516,891 [15],[28],[29],[30] 8,516,891 [15],[28],[29],[30] 8,516,891 [15],[28],[29],[30] 8,516,891 [15],[28],[29],[30] 8,516,891 [15],[28],[29],[30] 8,516,891 [15],[28],[29],[30] 8,516,891 [15],[28],[29],[30] 8,554,983 [6],[23],[24],[31],[32] 8,554,983 [6],[23],[24],[31],[32] 8,554,983 [6],[23],[24],[31],[32] 8,554,983 [6],[23],[24],[31],[32] 8,554,983 [6],[23],[24],[31],[32] 8,554,983 [6],[23],[24],[31],[32] 8,554,983 [6],[23],[24],[31],[32]  
Amortized cost $ 14.0 [15],[28],[29],[30]             $ 14.1 [23],[24],[31],[32]              
Fair value (6.3) [3],[15],[28],[29],[30]             (23.1) [2],[23],[24],[31],[32]              
Investment, Identifier [Axis]: 801 5th Ave, Seattle, Structure Mezzanine                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (58.9)             $ (57.2)             (29.4)
Investment, Identifier [Axis]: 801 5th Ave, Seattle, Structure Mezzanine, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[29],[30] 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%                
Interest rate, paid in kind 3.00% [12],[15],[29],[30] 3.00% [12],[15],[29],[30] 3.00% [12],[15],[29],[30] 3.00% [12],[15],[29],[30] 3.00% [12],[15],[29],[30] 3.00% [12],[15],[29],[30] 3.00% [12],[15],[29],[30] 3.00% [7],[24],[31],[32] 3.00% [7],[24],[31],[32] 3.00% [7],[24],[31],[32] 3.00% [7],[24],[31],[32] 3.00% [7],[24],[31],[32] 3.00% [7],[24],[31],[32] 3.00% [7],[24],[31],[32]  
Principal amount $ 58.9 [15],[17],[29],[30]             $ 57.2 [6],[24],[31],[32]              
Amortized cost 57.0 [15],[29],[30]             55.1 [24],[31],[32]              
Fair value $ (58.9) [3],[15],[29],[30]             $ (57.2) [2],[24],[31],[32]              
Investment, Identifier [Axis]: 801 5th Ave, Seattle, Structure Mezzanine, Real Estate | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 3.00% [12],[15],[29],[30] 3.00% [12],[15],[29],[30] 3.00% [12],[15],[29],[30] 3.00% [12],[15],[29],[30] 3.00% [12],[15],[29],[30] 3.00% [12],[15],[29],[30] 3.00% [12],[15],[29],[30] 3.00% [7],[24],[31],[32] 3.00% [7],[24],[31],[32] 3.00% [7],[24],[31],[32] 3.00% [7],[24],[31],[32] 3.00% [7],[24],[31],[32] 3.00% [7],[24],[31],[32] 3.00% [7],[24],[31],[32]  
Investment, Identifier [Axis]: ABB CONCISE Optical Group LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               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%  
Principal amount               $ 16.2              
Amortized cost               14.5              
Fair value               (15.7)              
Investment, Identifier [Axis]: ASG Technologies, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               0.0             (42.7)
Investment, Identifier [Axis]: ASG Technologies, Warrants                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               $ 0.0             (3.5)
Investment, Identifier [Axis]: ATX Networks Corp                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[24],[31],[32],[33]               10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%  
Principal amount [6],[20],[23],[24],[31],[32],[33]               $ 18.3              
Amortized cost [20],[23],[24],[31],[32],[33]               4.8              
Fair value [2],[20],[23],[24],[31],[32],[33]               $ (7.1)              
Investment, Identifier [Axis]: ATX Networks Corp | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[24],[31],[32],[33]               10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%  
Investment, Identifier [Axis]: ATX Networks Corp 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [24],[31],[32],[33]               7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%  
Base rate floor [24],[31],[32],[33]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[24],[31],[32],[33]               $ 46.8              
Amortized cost [24],[31],[32],[33]               46.8              
Fair value $ (40.6)             (46.8) [2],[24],[31],[32],[33]             0.0
Investment, Identifier [Axis]: ATX Networks Corp 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (21.9)             (7.1)             0.0
Investment, Identifier [Axis]: ATX Networks Corp, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[29],[30],[34] 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%                
Base rate floor [15],[29],[30],[34] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[29],[30],[34] $ 40.6                            
Amortized cost [15],[29],[30],[34] 40.6                            
Fair value [3],[15],[29],[30],[34] $ (40.6)                            
Investment, Identifier [Axis]: ATX Networks Corp, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%                
Principal amount [15],[17],[29],[30],[34],[35] $ 21.9                            
Amortized cost [15],[29],[30],[34],[35] 8.4                            
Fair value [3],[15],[29],[30],[34],[35] $ (21.9)                            
Investment, Identifier [Axis]: ATX Networks Corp, Capital Goods 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%                
Investment, Identifier [Axis]: ATX Networks Corp, Class B-1 Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (5.0)             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 [15],[28],[29],[30] 500 500 500 500 500 500 500                
Amortized cost [15],[28],[29],[30] $ 5.0                            
Fair value [1],[15],[28],[29],[30] (5.0)                            
Investment, Identifier [Axis]: ATX Networks Corp, Class B-2 Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (9.0)             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 [15],[28],[29],[30] 900 900 900 900 900 900 900                
Amortized cost [15],[28],[29],[30] $ 4.0                            
Fair value [1],[15],[28],[29],[30] (9.0)                            
Investment, Identifier [Axis]: ATX Networks Corp, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (29.2)             $ 0.0             0.0
Investment, Identifier [Axis]: ATX Networks Corp, Common Stock, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 4,214 [15],[28],[29],[30],[34],[35] 4,214 [15],[28],[29],[30],[34],[35] 4,214 [15],[28],[29],[30],[34],[35] 4,214 [15],[28],[29],[30],[34],[35] 4,214 [15],[28],[29],[30],[34],[35] 4,214 [15],[28],[29],[30],[34],[35] 4,214 [15],[28],[29],[30],[34],[35] 3,483 [23],[24],[31],[32],[33] 3,483 [23],[24],[31],[32],[33] 3,483 [23],[24],[31],[32],[33] 3,483 [23],[24],[31],[32],[33] 3,483 [23],[24],[31],[32],[33] 3,483 [23],[24],[31],[32],[33] 3,483 [23],[24],[31],[32],[33]  
Amortized cost $ 1.7 [15],[28],[29],[30],[34],[35]             $ 0.0 [23],[24],[31],[32],[33]              
Fair value $ (29.2) [1],[15],[28],[29],[30],[34],[35]             $ 0.0 [2],[23],[24],[31],[32],[33]              
Investment, Identifier [Axis]: AVF Parent LLC, Trade Claim, Retailing                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 44,507 [15],[28] 44,507 [15],[28] 44,507 [15],[28] 44,507 [15],[28] 44,507 [15],[28] 44,507 [15],[28] 44,507 [15],[28] 44,507 [23],[32] 44,507 [23],[32] 44,507 [23],[32] 44,507 [23],[32] 44,507 [23],[32] 44,507 [23],[32] 44,507 [23],[32]  
Amortized cost $ 0.0 [15],[28]             $ 0.0 [23],[32]              
Fair value $ 0.0 [1],[15],[28]             $ 0.0 [2],[23],[32]              
Investment, Identifier [Axis]: Abaco Energy Technologies LLC, Common Stock, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 3,055,556 [15],[28] 3,055,556 [15],[28] 3,055,556 [15],[28] 3,055,556 [15],[28] 3,055,556 [15],[28] 3,055,556 [15],[28] 3,055,556 [15],[28] 3,055,556 [23],[32] 3,055,556 [23],[32] 3,055,556 [23],[32] 3,055,556 [23],[32] 3,055,556 [23],[32] 3,055,556 [23],[32] 3,055,556 [23],[32]  
Amortized cost $ 0.2 [15],[28]             $ 0.2 [23],[32]              
Fair value $ (0.5) [1],[15],[28]             $ (0.3) [2],[23],[32]              
Investment, Identifier [Axis]: Abaco Energy Technologies LLC, Preferred Stock, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 12,734,481 [15],[28] 12,734,481 [15],[28] 12,734,481 [15],[28] 12,734,481 [15],[28] 12,734,481 [15],[28] 12,734,481 [15],[28] 12,734,481 [15],[28] 12,734,481 [23],[32] 12,734,481 [23],[32] 12,734,481 [23],[32] 12,734,481 [23],[32] 12,734,481 [23],[32] 12,734,481 [23],[32] 12,734,481 [23],[32]  
Amortized cost $ 1.5 [15],[28]             $ 1.5 [23],[32]              
Fair value $ (3.7) [1],[15],[28]             $ (1.7) [2],[23],[32]              
Investment, Identifier [Axis]: Abacus JV, Private Equity | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 31,400,804 31,400,804 31,400,804 31,400,804 31,400,804 31,400,804 31,400,804                
Amortized cost $ 32.2                            
Fair value $ (34.0)                            
Investment, Identifier [Axis]: Abacus JV, Private Equity 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares               31,916,927 31,916,927 31,916,927 31,916,927 31,916,927 31,916,927 31,916,927  
Amortized cost               $ 32.7              
Fair value               $ (34.2)              
Investment, Identifier [Axis]: Abacus JV, Private Equity, Insurance                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 49,223,047 [15],[29] 49,223,047 [15],[29] 49,223,047 [15],[29] 49,223,047 [15],[29] 49,223,047 [15],[29] 49,223,047 [15],[29] 49,223,047 [15],[29] 44,833,382 [6],[24],[32] 44,833,382 [6],[24],[32] 44,833,382 [6],[24],[32] 44,833,382 [6],[24],[32] 44,833,382 [6],[24],[32] 44,833,382 [6],[24],[32] 44,833,382 [6],[24],[32]  
Amortized cost $ 48.2 [15],[29]             $ 43.8 [24],[32]              
Fair value $ (53.3) [3],[15],[29]             $ (48.1) [2],[24],[32]              
Investment, Identifier [Axis]: Accelerator Investments Aggregator LP, Private Equity, Diversified Financials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 3,869,291 [15],[28],[29] 3,869,291 [15],[28],[29] 3,869,291 [15],[28],[29] 3,869,291 [15],[28],[29] 3,869,291 [15],[28],[29] 3,869,291 [15],[28],[29] 3,869,291 [15],[28],[29] 5,397,365 [6],[23],[24],[32] 5,397,365 [6],[23],[24],[32] 5,397,365 [6],[23],[24],[32] 5,397,365 [6],[23],[24],[32] 5,397,365 [6],[23],[24],[32] 5,397,365 [6],[23],[24],[32] 5,397,365 [6],[23],[24],[32]  
Amortized cost $ 4.5 [15],[28],[29]             $ 6.3 [23],[24],[32]              
Fair value $ (3.4) [3],[15],[28],[29]             $ (4.7) [2],[23],[24],[32]              
Investment, Identifier [Axis]: Access CIG LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 2.5             $ 2.5              
Amortized cost 2.3             2.2              
Fair value $ (2.2)             $ (2.5)              
Investment, Identifier [Axis]: Accuride Corp                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [9],[36]               5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%  
Base rate floor [9],[36]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[9],[36]               $ 9.0              
Amortized cost [9],[36]               8.1              
Fair value [2],[9],[36]               $ (8.7)              
Investment, Identifier [Axis]: Accuride Corp | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 20.8                            
Amortized cost 20.4                            
Fair value $ (17.7)                            
Investment, Identifier [Axis]: Accuride Corp 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               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%  
Principal amount               $ 21.0              
Amortized cost               20.3              
Fair value               $ (20.3)              
Investment, Identifier [Axis]: Accuride Corp, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[14],[37] 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%                
Base rate floor [14],[37] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [14],[17],[37] $ 8.9                            
Amortized cost [14],[37] 8.4                            
Fair value [3],[14],[37] $ (7.6)                            
Investment, Identifier [Axis]: Advanced Dermatology & Cosmetic Surgery ,Senior Secured Loans—First Lien, Health Care Equipment & Services, Maturing May, 7 2026                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 3.6              
Amortized cost [5]               3.6              
Fair value [2],[5]               $ (3.6)              
Investment, Identifier [Axis]: Advanced Dermatology & Cosmetic Surgery ,Senior Secured Loans—First Lien, Health Care Equipment & Services, Maturing May, 7 2027 - 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[38],[39]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [32],[38],[39]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[38],[39]               $ 44.8              
Amortized cost [32],[38],[39]               42.9              
Fair value [2],[32],[38],[39]               $ (45.0)              
Investment, Identifier [Axis]: Advanced Dermatology & Cosmetic Surgery ,Senior Secured Loans—First Lien, Health Care Equipment & Services, Maturing May, 7 2027- 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 4.2              
Amortized cost [5]               4.2              
Fair value [2],[5]               (4.2)              
Investment, Identifier [Axis]: Advanced Dermatology & Cosmetic Surgery, Health Care Equipment & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[19],[40] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [15],[19],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[19],[40] $ 46.3                            
Amortized cost [15],[19],[40] 44.7                            
Fair value [3],[15],[19],[40] $ (45.6)                            
Investment, Identifier [Axis]: Advanced Dermatology & Cosmetic Surgery, Health Care Equipment & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 2.2                            
Amortized cost [15] 2.2                            
Fair value [3],[15] $ (2.2)                            
Investment, Identifier [Axis]: Advanced Dermatology & Cosmetic Surgery, Health Care Equipment & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 3.6                            
Amortized cost [4] 3.6                            
Fair value [3],[4] $ (3.5)                            
Investment, Identifier [Axis]: Advanced Lighting Technologies Inc 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               0.0             (12.0)
Investment, Identifier [Axis]: Advanced Lighting Technologies Inc 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               0.0             0.0
Investment, Identifier [Axis]: Advanced Lighting Technologies Inc, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               $ 0.0             0.0
Investment, Identifier [Axis]: Advanced Lighting Technologies Inc, Materials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 16.00% 16.00% 16.00% 16.00% 16.00% 16.00% 16.00%                
Base rate floor [15],[25],[28] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[25],[28] $ 13.5                            
Amortized cost [15],[25],[28] 10.5                            
Fair value [3],[15],[25],[28] $ (3.4)                            
Investment, Identifier [Axis]: Advanced Lighting Technologies Inc, Materials | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 16.00% 16.00% 16.00% 16.00% 16.00% 16.00% 16.00%                
Investment, Identifier [Axis]: Advanced Lighting Technologies Inc, Senior Secured Loans, Second Lien                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [20],[23],[32]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [20],[23],[32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[20],[23],[32]               $ 11.3              
Amortized cost [20],[23],[32]               10.5              
Fair value [2],[20],[23],[32]               (6.4)              
Investment, Identifier [Axis]: Advanced Lighting Technologies Inc, Warrant                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               $ 0.0             0.0
Investment, Identifier [Axis]: Advania Sverige 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10%                
Interest rate, paid in kind 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | kr   kr 588.0                          
Amortized cost $ 66.6                            
Fair value $ (54.1)                            
Investment, Identifier [Axis]: Advania Sverige 1 | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30%                
Investment, Identifier [Axis]: Advania Sverige 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10%                
Interest rate, paid in kind 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | kr     kr 1,644.9                        
Amortized cost $ 12.8                            
Fair value $ (11.2)                            
Investment, Identifier [Axis]: Advania Sverige 2 | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30%                
Investment, Identifier [Axis]: Advania Sverige AB 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10%  
Interest rate, paid in kind               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base rate floor               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount               $ 588.0              
Amortized cost               66.4              
Fair value               $ (64.3)              
Investment, Identifier [Axis]: Advania Sverige AB 1 | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind               3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30%  
Investment, Identifier [Axis]: Advania Sverige AB 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10%  
Interest rate, paid in kind               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base rate floor               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount               $ 1,644.9              
Amortized cost               12.8              
Fair value               $ (12.5)              
Investment, Identifier [Axis]: Advania Sverige AB 2 | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind               3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30%  
Investment, Identifier [Axis]: Advania Sverige AB, Senior Secured Loans—First Lien, Software & Services, April 28, 2028 - 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [24],[32]               6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10%  
Interest rate, paid in kind [24],[32]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base rate floor [24],[32]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | kr [6],[24],[32]                 kr 629.4            
Amortized cost [24],[32]               $ 67.9              
Fair value [2],[24],[32]               $ (68.9)              
Investment, Identifier [Axis]: Advania Sverige AB, Senior Secured Loans—First Lien, Software & Services, April 28, 2028 - 1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [24],[32]               3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30%  
Investment, Identifier [Axis]: Advania Sverige AB, Senior Secured Loans—First Lien, Software & Services, April 28, 2028 -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [24],[32]               6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10%  
Interest rate, paid in kind [24],[32]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base rate floor [24],[32]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | kr [6],[24],[32]                   kr 1,345.8          
Amortized cost [24],[32]               $ 10.0              
Fair value [2],[24],[32]               $ (10.3)              
Investment, Identifier [Axis]: Advania Sverige AB, Senior Secured Loans—First Lien, Software & Services, April 28, 2028 -2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [24],[32]               3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30%  
Investment, Identifier [Axis]: Advania Sverige AB, Senior Secured Loans—First Lien, Software & Services, April 28, 2028 -3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5],[24]               6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10%  
Interest rate, paid in kind [5],[24]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base rate floor [5],[24]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | kr [5],[6],[24]                 kr 304.1            
Amortized cost [5],[24]               $ 37.5              
Fair value [2],[5],[24]               $ (37.2)              
Investment, Identifier [Axis]: Advania Sverige AB, Senior Secured Loans—First Lien, Software & Services, April 28, 2028 -3 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [5],[24]               3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30%  
Investment, Identifier [Axis]: Advania Sverige AB, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[29] 6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10%                
Interest rate, paid in kind [12],[15],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor [15],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | kr [15],[17],[29]   kr 933.6                          
Amortized cost [15],[29] $ 106.1                            
Fair value [3],[15],[29] $ (86.0)                            
Investment, Identifier [Axis]: Advania Sverige AB, Software & Services 1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15],[29] 3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30%                
Investment, Identifier [Axis]: Advania Sverige AB, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[29] 6.10% 6.10% 6.10% 6.10% 6.10% 6.10% 6.10%                
Interest rate, paid in kind [12],[15],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor [15],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | kr [15],[17],[29]     kr 1,345.8                        
Amortized cost [15],[29] $ 10.1                            
Fair value [3],[15],[29] $ (9.2)                            
Investment, Identifier [Axis]: Advania Sverige AB, Software & Services 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15],[29] 3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30%                
Investment, Identifier [Axis]: Affordable Care Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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%  
Interest rate, paid in kind 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%  
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 $ 76.1             $ 55.9              
Amortized cost 75.6             55.6              
Fair value $ (74.6)             $ (55.6)              
Investment, Identifier [Axis]: Affordable Care Inc | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 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%  
Investment, Identifier [Axis]: Affordable Care Inc 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ 0.0             0.0
Investment, Identifier [Axis]: Affordable Care Inc 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value (53.1)             (59.9)             0.0
Investment, Identifier [Axis]: Affordable Care Inc, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (49.9)             $ (52.1)             0.0
Investment, Identifier [Axis]: Affordable Care Inc, Health Care Equipment & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[40],[41] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Interest rate, paid in kind [12],[15],[40],[41] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor [15],[40],[41] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17],[40],[41] $ 53.6                            
Amortized cost [15],[40],[41] 53.3                            
Fair value [3],[15],[40],[41] $ (52.5)                            
Investment, Identifier [Axis]: Affordable Care Inc, Health Care Equipment & Services 1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15],[40],[41] 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30%                
Investment, Identifier [Axis]: Affordable Care Inc, Health Care Equipment & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[41] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Interest rate, paid in kind [12],[15],[41] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor [15],[41] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17],[41] $ 1.4                            
Amortized cost [15],[41] 1.4                            
Fair value [3],[15],[41] $ (1.4)                            
Investment, Identifier [Axis]: Affordable Care Inc, Health Care Equipment & Services 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15],[41] 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30%                
Investment, Identifier [Axis]: Affordable Care Inc, Health Care Equipment & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12],[41] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Interest rate, paid in kind [4],[12],[41] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor [4],[41] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17],[41] $ 28.4                            
Amortized cost [4],[41] 28.4                            
Fair value [3],[4],[41] $ (27.8)                            
Investment, Identifier [Axis]: Affordable Care Inc, Health Care Equipment & Services 3 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [4],[12],[41] 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30%                
Investment, Identifier [Axis]: Affordable Care Inc, Health Care Equipment & Services 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12],[41] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Interest rate, paid in kind [4],[12],[41] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor [4],[41] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17],[41] $ 11.4                            
Amortized cost [4],[41] 11.4                            
Fair value [3],[4],[41] $ (11.2)                            
Investment, Identifier [Axis]: Affordable Care Inc, Health Care Equipment & Services 4 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [4],[12],[41] 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30%                
Investment, Identifier [Axis]: Affordable Care Inc, Preferred Stock, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 11.80% [12],[15],[41] 11.80% [12],[15],[41] 11.80% [12],[15],[41] 11.80% [12],[15],[41] 11.80% [12],[15],[41] 11.80% [12],[15],[41] 11.80% [12],[15],[41] 11.80% [7],[32],[42] 11.80% [7],[32],[42] 11.80% [7],[32],[42] 11.80% [7],[32],[42] 11.80% [7],[32],[42] 11.80% [7],[32],[42] 11.80% [7],[32],[42]  
Number of shares | shares 49,073,000 [15],[41] 49,073,000 [15],[41] 49,073,000 [15],[41] 49,073,000 [15],[41] 49,073,000 [15],[41] 49,073,000 [15],[41] 49,073,000 [15],[41] 49,073,000 [32],[42] 49,073,000 [32],[42] 49,073,000 [32],[42] 49,073,000 [32],[42] 49,073,000 [32],[42] 49,073,000 [32],[42] 49,073,000 [32],[42]  
Amortized cost $ 48.1 [15],[41]             $ 48.1 [32],[42]              
Fair value $ (49.9) [1],[15],[41]             $ (52.1) [2],[32],[42]              
Investment, Identifier [Axis]: Affordable Care Inc, Preferred Stock, Health Care Equipment & Services | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 11.80% [12],[15],[41] 11.80% [12],[15],[41] 11.80% [12],[15],[41] 11.80% [12],[15],[41] 11.80% [12],[15],[41] 11.80% [12],[15],[41] 11.80% [12],[15],[41] 11.80% [7],[32],[42] 11.80% [7],[32],[42] 11.80% [7],[32],[42] 11.80% [7],[32],[42] 11.80% [7],[32],[42] 11.80% [7],[32],[42] 11.80% [7],[32],[42]  
Investment, Identifier [Axis]: Affordable Care Inc, Senior Secured Loans—First Lien, Health Care Equipment & Services, Maturing August 2, 2027                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5],[42]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Interest rate, paid in kind [5],[42]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base rate floor [5],[42]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6],[42]               $ 12.8              
Amortized cost [5],[42]               12.8              
Fair value [2],[5],[42]               $ (12.8)              
Investment, Identifier [Axis]: Affordable Care Inc, Senior Secured Loans—First Lien, Health Care Equipment & Services, Maturing August 2, 2027 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [5],[42]               1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30%  
Investment, Identifier [Axis]: Affordable Care Inc, Senior Secured Loans—First Lien, Health Care Equipment & Services, Maturing August 2, 2028 -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[42]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Interest rate, paid in kind [32],[42]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base rate floor [32],[42]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[32],[42]               $ 60.4              
Amortized cost [32],[42]               59.9              
Fair value [2],[32],[42]               $ (60.1)              
Investment, Identifier [Axis]: Affordable Care Inc, Senior Secured Loans—First Lien, Health Care Equipment & Services, Maturing August 2, 2028 -1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32],[42]               1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30%  
Investment, Identifier [Axis]: Affordable Care Inc, Senior Secured Loans—First Lien, Health Care Equipment & Services, Maturing August 2, 2028 -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5],[42]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Interest rate, paid in kind [5],[42]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base rate floor [5],[42]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6],[42]               $ 43.1              
Amortized cost [5],[42]               43.1              
Fair value [2],[5],[42]               $ (42.9)              
Investment, Identifier [Axis]: Affordable Care Inc, Senior Secured Loans—First Lien, Health Care Equipment & Services, Maturing August 2, 2028 -2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [5],[42]               1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30%  
Investment, Identifier [Axis]: Alacrity Solutions Group LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 40.6                            
Amortized cost 39.9                            
Fair value $ (39.1)                            
Investment, Identifier [Axis]: Alacrity Solutions Group LLC, Senior Secured Loans—First Lien, Insurance, Maturing December 22, 2027 -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%  
Base rate floor [32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[32]               $ 1.1              
Amortized cost [32]               0.9              
Fair value [2],[32]               $ (1.1)              
Investment, Identifier [Axis]: Alacrity Solutions Group LLC, Senior Secured Loans—First Lien, Insurance, Maturing December 22, 2027-2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 9.7              
Amortized cost [5]               9.7              
Fair value [2],[5]               $ (9.5)              
Investment, Identifier [Axis]: Alacrity Solutions Group LLC, Senior Secured Loans—First Lien, Insurance, Maturing December 22, 2028                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%  
Base rate floor [32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[32]               $ 69.2              
Amortized cost [32]               68.2              
Fair value [2],[32]               $ (68.2)              
Investment, Identifier [Axis]: Alacrity Solutions Group LLC, Insurance 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 28.4                            
Amortized cost [15] 28.0                            
Fair value [3],[15] $ (27.3)                            
Investment, Identifier [Axis]: Alacrity Solutions Group LLC, Insurance 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 10.8                            
Amortized cost [4] 10.6                            
Fair value [3],[4] $ (10.4)                            
Investment, Identifier [Axis]: Alera Group Intermediate Holdings Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 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 $ 32.3             $ 20.2              
Amortized cost 31.9             20.0              
Fair value $ (30.7)             $ (20.0)              
Investment, Identifier [Axis]: Alera Group Intermediate Holdings Inc, Alacrity Solutions Group LLC, Senior Secured Loans—First Lien, Insurance, Maturing October 2, 2028 -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[32]               $ 21.4              
Amortized cost [32]               21.2              
Fair value [2],[32]               $ (21.2)              
Investment, Identifier [Axis]: Alera Group Intermediate Holdings Inc, Alacrity Solutions Group LLC, Senior Secured Loans—First Lien, Insurance, Maturing October 2, 2028 -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 22.9              
Amortized cost [5]               22.9              
Fair value [2],[5]               $ (22.7)              
Investment, Identifier [Axis]: Alera Group Intermediate Holdings Inc, Insurance 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [40] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [17],[40] $ 9.2                            
Amortized cost [40] 9.1                            
Fair value [3],[40] $ (8.7)                            
Investment, Identifier [Axis]: Alera Group Intermediate Holdings Inc, Insurance 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [15],[40] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17],[40] $ 22.5                            
Amortized cost [15],[40] 22.5                            
Fair value [3],[15],[40] $ (21.4)                            
Investment, Identifier [Axis]: Alstom SA | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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%  
Interest rate, paid in kind 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 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 $ 6.2             $ 6.1              
Amortized cost 5.8             5.3              
Fair value $ (3.5)             $ (5.0)              
Investment, Identifier [Axis]: Alstom SA | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 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%  
Investment, Identifier [Axis]: Altavair AirFinance, Private Equity | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 36,500,000 36,500,000 36,500,000 36,500,000 36,500,000 36,500,000 36,500,000                
Amortized cost $ 43.0                            
Fair value $ (42.2)                            
Investment, Identifier [Axis]: Altavair AirFinance, Private Equity 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares               36,500,000 36,500,000 36,500,000 36,500,000 36,500,000 36,500,000 36,500,000  
Amortized cost               $ 43.0              
Fair value               $ (44.1)              
Investment, Identifier [Axis]: Altavair AirFinance, Private Equity, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 140,212,883 [15],[29] 140,212,883 [15],[29] 140,212,883 [15],[29] 140,212,883 [15],[29] 140,212,883 [15],[29] 140,212,883 [15],[29] 140,212,883 [15],[29] 94,679,609 [6],[24],[32] 94,679,609 [6],[24],[32] 94,679,609 [6],[24],[32] 94,679,609 [6],[24],[32] 94,679,609 [6],[24],[32] 94,679,609 [6],[24],[32] 94,679,609 [6],[24],[32]  
Amortized cost $ 141.1 [15],[29]             $ 95.6 [24],[32]              
Fair value $ (162.1) [3],[15],[29]             $ (114.3) [2],[24],[32]              
Investment, Identifier [Axis]: American Airlines Group Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 2.5                            
Amortized cost 2.3                            
Fair value $ (2.4)                            
Investment, Identifier [Axis]: American Vision Partners | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 19.5                            
Amortized cost 19.3                            
Fair value $ (18.9)                            
Investment, Identifier [Axis]: American Vision Partners, Health Care Equipment & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[16] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [15],[16] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[16],[17] $ 113.0                            
Amortized cost [15],[16] 112.5                            
Fair value [3],[15],[16] $ (109.1)                            
Investment, Identifier [Axis]: American Vision Partners, Health Care Equipment & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 7.8                            
Amortized cost [4] 7.8                            
Fair value [3],[4] $ (7.5)                            
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 [15],[28] 2,655,491 [15],[28] 2,655,491 [15],[28] 2,655,491 [15],[28] 2,655,491 [15],[28] 2,655,491 [15],[28] 2,655,491 [15],[28] 2,450,230 [23],[32] 2,450,230 [23],[32] 2,450,230 [23],[32] 2,450,230 [23],[32] 2,450,230 [23],[32] 2,450,230 [23],[32] 2,450,230 [23],[32]  
Amortized cost $ 2.7 [15],[28]             $ 2.5 [23],[32]              
Fair value $ (2.2) [1],[15],[28]             $ (2.4) [2],[23],[32]              
Investment, Identifier [Axis]: American Vision Partners, Senior Secured Loans—First Lien, Health Care Equipment & Services, Maturing September 30, 2026                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 7.8              
Amortized cost [5]               7.8              
Fair value [2],[5]               $ (7.7)              
Investment, Identifier [Axis]: American Vision Partners, Senior Secured Loans—First Lien, Health Care Equipment & Services, Maturing September 30, 2027 -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [10],[32]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [10],[32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[10],[32]               $ 94.7              
Amortized cost [10],[32]               93.8              
Fair value [2],[10],[32]               $ (94.3)              
Investment, Identifier [Axis]: American Vision Partners, Senior Secured Loans—First Lien, Health Care Equipment & Services, Maturing September 30, 2027 -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 38.9              
Amortized cost [5]               38.9              
Fair value [2],[5]               $ (38.7)              
Investment, Identifier [Axis]: Amerivet Partners Management Inc, Health Care Equipment & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 95.4                            
Amortized cost [15] 94.5                            
Fair value [3],[15] $ (91.8)                            
Investment, Identifier [Axis]: Amerivet Partners Management Inc, Health Care Equipment & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 17.2                            
Amortized cost [15] 17.2                            
Fair value [3],[15] $ (16.6)                            
Investment, Identifier [Axis]: Amerivet Partners Management Inc, Health Care Equipment & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 8.4                            
Amortized cost [4] 8.4                            
Fair value [3],[4] $ (8.1)                            
Investment, Identifier [Axis]: Amerivet Partners Management Inc, Health Care Equipment & Services 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 50.1                            
Amortized cost [4] 50.1                            
Fair value [3],[4] $ (48.2)                            
Investment, Identifier [Axis]: Amerivet Partners Management Inc, Preferred Stock, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15] 11.50% 11.50% 11.50% 11.50% 11.50% 11.50% 11.50%                
Number of shares | shares [15] 12,702,290 12,702,290 12,702,290 12,702,290 12,702,290 12,702,290 12,702,290                
Amortized cost [15] $ 12.3                            
Fair value [1],[15] $ (11.8)                            
Investment, Identifier [Axis]: Amerivet Partners Management Inc, Preferred Stock, Health Care Equipment & Services | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15] 11.50% 11.50% 11.50% 11.50% 11.50% 11.50% 11.50%                
Investment, Identifier [Axis]: Ammeraal Beltech Holding BV                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [24],[32],[33],[43]               7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75%  
Base rate floor [24],[32],[33],[43]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount [6],[24],[32],[33],[43]               $ 44.9              
Amortized cost [24],[32],[33],[43]               40.8              
Fair value [2],[24],[32],[33],[43]               $ (44.3)              
Investment, Identifier [Axis]: Ammeraal Beltech Holding BV | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount | €       € 4.8                      
Amortized cost $ 4.8                            
Fair value $ (4.8)                            
Investment, Identifier [Axis]: Ammeraal Beltech Holding BV 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 42.8             $ 81.5              
Amortized cost 42.1             79.8              
Fair value $ (41.8)             $ (80.3)              
Investment, Identifier [Axis]: Ammeraal Beltech Holding BV, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75%                
Base rate floor [15],[18],[29],[34] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount [15],[17],[18],[29],[34] $ 23.6                            
Amortized cost [15],[18],[29],[34] 21.8                            
Fair value [3],[15],[18],[29],[34] (23.0)                            
Investment, Identifier [Axis]: Ammeraal Beltech Holding BV, Senior Secured Loans, First Lien | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50%  
Base rate floor               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | €                     € 4.8        
Amortized cost               $ 4.7              
Fair value               $ (5.4)              
Investment, Identifier [Axis]: Amtek Global Technology Pte Ltd                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[24],[31],[32]               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Base rate floor [20],[23],[24],[31],[32]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | € [6],[20],[23],[24],[31],[32]                     € 34.7        
Amortized cost [20],[23],[24],[31],[32]               $ 39.1              
Fair value [2],[20],[23],[24],[31],[32]               $ 0.0              
Investment, Identifier [Axis]: Amtek Global Technology Pte Ltd | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[24],[31],[32]               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Investment, Identifier [Axis]: Amtek Global Technology Pte Ltd 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[24],[31],[32]               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Base rate floor [20],[23],[24],[31],[32]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | € [6],[20],[23],[24],[31],[32]                     € 57.2        
Amortized cost [20],[23],[24],[31],[32]               $ 68.7              
Fair value (3.9)             $ (34.8) [2],[20],[23],[24],[31],[32]             (59.7)
Investment, Identifier [Axis]: Amtek Global Technology Pte Ltd 1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[24],[31],[32]               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Investment, Identifier [Axis]: Amtek Global Technology Pte Ltd 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value 0.0             $ 0.0             (0.1)
Investment, Identifier [Axis]: Amtek Global Technology Pte Ltd, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ 0.0             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 [15],[28],[29],[30],[44] 7,046,126 [15],[28],[29],[30],[44] 7,046,126 [15],[28],[29],[30],[44] 7,046,126 [15],[28],[29],[30],[44] 7,046,126 [15],[28],[29],[30],[44] 7,046,126 [15],[28],[29],[30],[44] 7,046,126 [15],[28],[29],[30],[44] 7,046,126 [23],[24],[31],[32],[45] 7,046,126 [23],[24],[31],[32],[45] 7,046,126 [23],[24],[31],[32],[45] 7,046,126 [23],[24],[31],[32],[45] 7,046,126 [23],[24],[31],[32],[45] 7,046,126 [23],[24],[31],[32],[45] 7,046,126 [23],[24],[31],[32],[45]  
Amortized cost $ 0.0 [15],[28],[29],[30],[44]             $ 0.0 [23],[24],[31],[32],[45]              
Fair value 0.0 [1],[15],[28],[29],[30],[44]             0.0 [2],[23],[24],[31],[32],[45]              
Investment, Identifier [Axis]: Amtek Global Technology Pte Ltd, Ordinary Shares                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ 0.0             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 [15],[28],[29],[30] 5,735,804,056 [15],[28],[29],[30] 5,735,804,056 [15],[28],[29],[30] 5,735,804,056 [15],[28],[29],[30] 5,735,804,056 [15],[28],[29],[30] 5,735,804,056 [15],[28],[29],[30] 5,735,804,056 [15],[28],[29],[30] 5,735,804,056 [23],[24],[31],[32] 5,735,804,056 [23],[24],[31],[32] 5,735,804,056 [23],[24],[31],[32] 5,735,804,056 [23],[24],[31],[32] 5,735,804,056 [23],[24],[31],[32] 5,735,804,056 [23],[24],[31],[32] 5,735,804,056 [23],[24],[31],[32]  
Amortized cost $ 30.7 [15],[28],[29],[30]             $ 30.7 [23],[24],[31],[32]              
Fair value 0.0 [1],[15],[28],[29],[30]             0.0 [2],[23],[24],[31],[32]              
Investment, Identifier [Axis]: Amtek Global Technology Pte Ltd, Private Equity                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ 0.0             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 [15],[28],[29],[30] 4,097 [15],[28],[29],[30] 4,097 [15],[28],[29],[30] 4,097 [15],[28],[29],[30] 4,097 [15],[28],[29],[30] 4,097 [15],[28],[29],[30] 4,097 [15],[28],[29],[30] 4,097 [23],[24],[31],[32] 4,097 [23],[24],[31],[32] 4,097 [23],[24],[31],[32] 4,097 [23],[24],[31],[32] 4,097 [23],[24],[31],[32] 4,097 [23],[24],[31],[32] 4,097 [23],[24],[31],[32]  
Amortized cost $ 0.0 [15],[28],[29],[30]             $ 0.0 [23],[24],[31],[32]              
Fair value $ 0.0 [1],[15],[28],[29],[30]             0.0 [2],[23],[24],[31],[32]              
Investment, Identifier [Axis]: Amtek Global Technology Pte Ltd, Trade Claim                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               $ 0.0             0.0
Investment, Identifier [Axis]: Angelica Corp                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[46]               10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%  
Principal amount [6],[20],[23],[46]               $ 53.4              
Amortized cost [20],[23],[46]               42.3              
Fair value [2],[20],[23],[46]               $ (5.2)              
Investment, Identifier [Axis]: Angelica Corp | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[46]               10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%  
Investment, Identifier [Axis]: Angelica Corp, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%                
Principal amount [17],[25],[28],[47] $ 59.0                            
Amortized cost [25],[28],[47] 42.3                            
Fair value [3],[25],[28],[47] $ (0.9)                            
Investment, Identifier [Axis]: Angelica Corp, Health Care Equipment & Services | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%                
Investment, Identifier [Axis]: Angelica Corp, Limited Partnership Interest, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 877,044 [28],[47] 877,044 [28],[47] 877,044 [28],[47] 877,044 [28],[47] 877,044 [28],[47] 877,044 [28],[47] 877,044 [28],[47] 877,044 [23],[46] 877,044 [23],[46] 877,044 [23],[46] 877,044 [23],[46] 877,044 [23],[46] 877,044 [23],[46] 877,044 [23],[46]  
Amortized cost $ 47.6 [28],[47]             $ 47.6 [23],[46]              
Fair value $ 0.0 [1],[28],[47]             $ 0.0 [2],[23],[46]              
Investment, Identifier [Axis]: Apex Group Limited                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [24],[32]               6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%  
Base rate floor [24],[32]               0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount [6],[24],[32]               $ 8.0              
Amortized cost [24],[32]               7.9              
Fair value [2],[24],[32]               $ (8.0)              
Investment, Identifier [Axis]: Apex Group Limited | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 40.0                            
Amortized cost 39.7                            
Fair value $ (37.6)                            
Investment, Identifier [Axis]: Apex Group Limited 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 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 $ 4.2             $ 32.0              
Amortized cost 4.2             31.7              
Fair value $ (4.0)             $ (32.0)              
Investment, Identifier [Axis]: Apex Group Limited 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 1.9                            
Fair value $ (1.6)                            
Investment, Identifier [Axis]: Apex Group Limited E+400 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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               $ 1.9              
Fair value               $ (1.8)              
Investment, Identifier [Axis]: Apex Group Limited L+375 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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               $ 4.2              
Amortized cost               4.2              
Fair value               $ (4.2)              
Investment, Identifier [Axis]: Apex Group Limited, Diversified Financials 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[29],[37] 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75%                
Base rate floor [15],[29],[37] 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount [15],[17],[29],[37] $ 2.5                            
Amortized cost [15],[29],[37] 2.5                            
Fair value [3],[15],[29],[37] $ (2.4)                            
Investment, Identifier [Axis]: Apex Group Limited, Diversified Financials 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[29],[37] 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00%                
Base rate floor [15],[29],[37] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | € [15],[17],[29],[37]       € 2.0                      
Amortized cost [15],[29],[37] $ 2.3                            
Fair value [3],[15],[29],[37] $ (2.0)                            
Investment, Identifier [Axis]: Apex Group Limited, Diversified Financials 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%                
Base rate floor [15],[29] 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount [15],[17],[29] $ 55.0                            
Amortized cost [15],[29] 54.0                            
Fair value [3],[15],[29] $ (51.7)                            
Investment, Identifier [Axis]: Arcfield Acquisition Corp | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 8.0                            
Amortized cost 8.0                            
Fair value $ (7.9)                            
Investment, Identifier [Axis]: Arcfield Acquisition Corp, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[16] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [16],[19] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [16],[17],[19] $ 40.3                            
Amortized cost [16],[19] 39.9                            
Fair value [3],[16],[19] $ (39.4)                            
Investment, Identifier [Axis]: Arcfield Acquisition Corp, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 7.1                            
Amortized cost [4] 7.1                            
Fair value [3],[4] $ (6.9)                            
Investment, Identifier [Axis]: Arcos LLC/VA | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 22.2             $ 22.4              
Amortized cost 22.0             22.2              
Fair value $ (20.6)             $ (22.3)              
Investment, Identifier [Axis]: Arcos LLC/VA, Preferred Stock, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 9.50% [12],[15] 9.50% [12],[15] 9.50% [12],[15] 9.50% [12],[15] 9.50% [12],[15] 9.50% [12],[15] 9.50% [12],[15] 9.50% [7],[32] 9.50% [7],[32] 9.50% [7],[32] 9.50% [7],[32] 9.50% [7],[32] 9.50% [7],[32] 9.50% [7],[32]  
Base rate floor 1.00% [15] 1.00% [15] 1.00% [15] 1.00% [15] 1.00% [15] 1.00% [15] 1.00% [15] 1.00% [32] 1.00% [32] 1.00% [32] 1.00% [32] 1.00% [32] 1.00% [32] 1.00% [32]  
Number of shares | shares 15,000,000 [15] 15,000,000 [15] 15,000,000 [15] 15,000,000 [15] 15,000,000 [15] 15,000,000 [15] 15,000,000 [15] 15,000,000 [32] 15,000,000 [32] 15,000,000 [32] 15,000,000 [32] 15,000,000 [32] 15,000,000 [32] 15,000,000 [32]  
Amortized cost $ 14.0 [15]             $ 14.0 [32]              
Fair value $ (13.4) [1],[15]             $ (15.5) [2],[32]              
Investment, Identifier [Axis]: Arcos LLC/VA, Preferred Stock, Software & Services | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 9.50% [12],[15] 9.50% [12],[15] 9.50% [12],[15] 9.50% [12],[15] 9.50% [12],[15] 9.50% [12],[15] 9.50% [12],[15] 9.50% [7],[32] 9.50% [7],[32] 9.50% [7],[32] 9.50% [7],[32] 9.50% [7],[32] 9.50% [7],[32] 9.50% [7],[32]  
Investment, Identifier [Axis]: Arcos LLC/VA, Senior Secured Loans—First Lien, Software & Services, Maturing April 20, 2027                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 4.5              
Amortized cost [5]               4.5              
Fair value [2],[5]               $ (4.5)              
Investment, Identifier [Axis]: Arcos LLC/VA, Senior Secured Loans—First Lien, Software & Services, Maturing March 31, 2028                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [39]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [39]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[39]               $ 12.5              
Amortized cost [39]               12.3              
Fair value [2],[39]               $ (12.4)              
Investment, Identifier [Axis]: Arcos LLC/VA, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[40] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [17],[40] $ 12.3                            
Amortized cost [40] 12.2                            
Fair value [3],[40] $ (11.4)                            
Investment, Identifier [Axis]: Arcos LLC/VA, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 4.5                            
Amortized cost [4] 4.5                            
Fair value [3],[4] $ (4.2)                            
Investment, Identifier [Axis]: Ardonagh Group Ltd                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [24],[32],[36]               12.80% 12.80% 12.80% 12.80% 12.80% 12.80% 12.80%  
Principal amount [6],[24],[32],[36]               $ 0.9              
Amortized cost [24],[32],[36]               0.9              
Fair value [2],[24],[32],[36]               $ (1.0)              
Investment, Identifier [Axis]: Ardonagh Group Ltd | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [24],[32],[36]               12.80% 12.80% 12.80% 12.80% 12.80% 12.80% 12.80%  
Investment, Identifier [Axis]: Ardonagh Group Ltd 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount | £         £ 3.8                    
Amortized cost $ 4.7                            
Fair value $ (4.5)                            
Investment, Identifier [Axis]: Ardonagh Group Ltd 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 | €       € 0.5                      
Amortized cost $ 0.5                            
Fair value $ (0.5)                            
Investment, Identifier [Axis]: Ardonagh Group Ltd 3 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 54.8                            
Amortized cost 54.3                            
Fair value $ (53.1)                            
Investment, Identifier [Axis]: Ardonagh Group Ltd E+675 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%  
Base rate floor               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount | €                     € 0.5        
Amortized cost               $ 0.5              
Fair value               $ (0.6)              
Investment, Identifier [Axis]: Ardonagh Group Ltd L+550 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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               $ 40.7              
Amortized cost               40.3              
Fair value               $ (40.3)              
Investment, Identifier [Axis]: Ardonagh Group Ltd L+675 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%  
Base rate floor               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount | £                       £ 3.8      
Amortized cost               $ 4.7              
Fair value               $ (5.2)              
Investment, Identifier [Axis]: Ardonagh Group Ltd, Insurance 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[29] 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%                
Base rate floor [15],[29] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount | £ [15],[17],[29]         £ 0.8                    
Amortized cost [15],[29] $ 1.0                            
Fair value [3],[15],[29] $ (0.9)                            
Investment, Identifier [Axis]: Ardonagh Group Ltd, Insurance 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12],[29] 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%                
Base rate floor [15],[29] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount | € [15],[17],[29]       € 19.0                      
Amortized cost [15],[29] $ 19.3                            
Fair value [3],[15],[29] $ (20.2)                            
Investment, Identifier [Axis]: Ardonagh Group Ltd, Insurance 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount [15],[17],[29],[37] $ 1.0                            
Amortized cost [15],[29],[37] 1.0                            
Fair value [3],[15],[29],[37] $ (0.9)                            
Investment, Identifier [Axis]: Ardonagh Group Ltd, Insurance 3 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 12.80% 12.80% 12.80% 12.80% 12.80% 12.80% 12.80%                
Investment, Identifier [Axis]: Ardonagh Group Ltd, Senior Secured Loans—First Lien, Insurance, Maturing July 14, 2026 - 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5],[24]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [5],[24]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount | £ [5],[6],[24]                       £ 16.7      
Amortized cost [5],[24]               $ 22.8              
Fair value [2],[5],[24]               $ (22.1)              
Investment, Identifier [Axis]: Ardonagh Group Ltd, Senior Secured Loans—First Lien, Insurance, Maturing July 14, 2026 -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [24],[32]               6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%  
Base rate floor [24],[32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount | £ [6],[24],[32]                       £ 0.8      
Amortized cost [24],[32]               $ 1.0              
Fair value [2],[24],[32]               $ (1.1)              
Investment, Identifier [Axis]: Ardonagh Group Ltd, Senior Secured Loans—First Lien, Insurance, Maturing July 14, 2026 -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [24],[32]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [24],[32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[24],[32]               $ 14.1              
Amortized cost [24],[32]               13.8              
Fair value [2],[24],[32]               $ (13.9)              
Investment, Identifier [Axis]: Ardonagh Ltd, Ordinary Shares, Insurance 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [23],[24],[32]               16,450 16,450 16,450 16,450 16,450 16,450 16,450  
Amortized cost [23],[24],[32]               $ 0.0              
Fair value [2],[23],[24],[32]               $ (2.8)              
Investment, Identifier [Axis]: Ardonagh Ltd, Ordinary Shares, Insurance 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [23],[24],[32]               116,814 116,814 116,814 116,814 116,814 116,814 116,814  
Amortized cost [23],[24],[32]               $ 0.2              
Fair value [2],[23],[24],[32]               $ (0.5)              
Investment, Identifier [Axis]: Ardonagh Ltd, Preferred Stock, Insurance                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [23],[24],[32]               6,113,719 6,113,719 6,113,719 6,113,719 6,113,719 6,113,719 6,113,719  
Amortized cost [23],[24],[32]               $ 9.1              
Fair value [2],[23],[24],[32]               $ (22.0)              
Investment, Identifier [Axis]: Arena Energy LP, Warrants, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 68,186,525 [15] 68,186,525 [15] 68,186,525 [15] 68,186,525 [15] 68,186,525 [15] 68,186,525 [15] 68,186,525 [15] 68,186,525 [23],[32] 68,186,525 [23],[32] 68,186,525 [23],[32] 68,186,525 [23],[32] 68,186,525 [23],[32] 68,186,525 [23],[32] 68,186,525 [23],[32]  
Amortized cost $ 0.4 [15]             $ 0.4 [23],[32]              
Fair value $ (0.5) [1],[15]             $ (0.6) [2],[23],[32]              
Investment, Identifier [Axis]: Arrotex Australia Group Pty Ltd 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount           $ 109.4                  
Amortized cost $ 73.9                            
Fair value $ (74.5)                            
Investment, Identifier [Axis]: Arrotex Australia Group Pty Ltd 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               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%  
Principal amount                         $ 109.4    
Amortized cost               $ 73.6              
Fair value               $ (79.7)              
Investment, Identifier [Axis]: Arrotex Australia Group Pty Ltd 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 5.7             $ 5.7              
Fair value $ (5.4)             $ (5.8)              
Investment, Identifier [Axis]: Arrotex Australia Group Pty Ltd, Senior Secured Loans—First Lien, Pharmaceuticals, Biotechnology & Life Sciences, July 10, 2024 -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [24],[32]               5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%  
Base rate floor [24],[32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[24],[32]                         $ 42.6    
Amortized cost [24],[32]               $ 30.4              
Fair value [2],[24],[32]               $ (30.9)              
Investment, Identifier [Axis]: Arrotex Australia Group Pty Ltd, Senior Secured Loans—First Lien, Pharmaceuticals, Biotechnology & Life Sciences, July 10, 2024 -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [24],[32]               5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%  
Base rate floor [24],[32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[24],[32]                         $ 3.1    
Amortized cost [24],[32]               $ 2.2              
Fair value [2],[24],[32]               $ (2.3)              
Investment, Identifier [Axis]: Arrotex Australia Group Pty Ltd, Pharmaceuticals, Biotechnology & Life Sciences | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 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%                
Principal amount           $ 25.0                  
Amortized cost $ 16.2                            
Fair value $ (17.0)                            
Investment, Identifier [Axis]: Arrotex Australia Group Pty Ltd, Pharmaceuticals, Biotechnology & Life Sciences | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 11.50% 11.50% 11.50% 11.50% 11.50% 11.50% 11.50%                
Investment, Identifier [Axis]: Arrotex Australia Group Pty Ltd, Pharmaceuticals, Biotechnology & Life Sciences 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[29] 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%                
Base rate floor [15],[29] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[29]           $ 42.6                  
Amortized cost [15],[29] $ 31.1                            
Fair value [3],[15],[29] $ (29.0)                            
Investment, Identifier [Axis]: Arrotex Australia Group Pty Ltd, Pharmaceuticals, Biotechnology & Life Sciences 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[29] 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%                
Base rate floor [15],[29] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[29]           $ 3.1                  
Amortized cost [15],[29] $ 2.2                            
Fair value [3],[15],[29] $ (2.1)                            
Investment, Identifier [Axis]: Ascent Resources Utica Holdings LLC / ARU Finance Corp, Common Stock | 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                
Amortized cost $ 3.6                            
Fair value $ (4.8)                            
Investment, Identifier [Axis]: Ascent Resources Utica Holdings LLC / ARU Finance Corp, Common Stock 1 | 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  
Amortized cost               $ 3.6              
Fair value               $ (3.1)              
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 [28],[48] 10,193 [28],[48] 10,193 [28],[48] 10,193 [28],[48] 10,193 [28],[48] 10,193 [28],[48] 10,193 [28],[48] 10,193 [23],[49] 10,193 [23],[49] 10,193 [23],[49] 10,193 [23],[49] 10,193 [23],[49] 10,193 [23],[49] 10,193 [23],[49]  
Amortized cost $ 9.7 [28],[48]             $ 9.7 [23],[49]              
Fair value $ (3.6) [1],[28],[48]             $ (2.3) [2],[23],[49]              
Investment, Identifier [Axis]: Ascent Resources Utica Holdings LLC / ARU Finance Corp, Trade Claim | 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 $ 30.5             $ 30.5              
Fair value $ (40.5)             $ (26.4)              
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 [28],[48] 86,607,143 [28],[48] 86,607,143 [28],[48] 86,607,143 [28],[48] 86,607,143 [28],[48] 86,607,143 [28],[48] 86,607,143 [28],[48] 86,607,143 [23],[49] 86,607,143 [23],[49] 86,607,143 [23],[49] 86,607,143 [23],[49] 86,607,143 [23],[49] 86,607,143 [23],[49] 86,607,143 [23],[49]  
Amortized cost $ 19.4 [28],[48]             $ 19.4 [23],[49]              
Fair value $ (30.5) [1],[28],[48]             $ (19.8) [2],[23],[49]              
Investment, Identifier [Axis]: Aspect Software Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32]               8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%  
Principal amount [6],[32]               $ 0.3              
Amortized cost [32]               0.2              
Fair value [2],[32]               $ (0.3)              
Investment, Identifier [Axis]: Aspect Software Inc | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32]               8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%  
Investment, Identifier [Axis]: Aspect Software Inc, Common Stock, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [9],[23],[32],[33]               1,309,955 1,309,955 1,309,955 1,309,955 1,309,955 1,309,955 1,309,955  
Amortized cost [9],[23],[32],[33]               $ 2.3              
Fair value [2],[9],[23],[32],[33]               $ (2.7)              
Investment, Identifier [Axis]: Aspect Software Inc, Warrant, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [9],[23],[32],[33]               181,730 181,730 181,730 181,730 181,730 181,730 181,730  
Amortized cost [9],[23],[32],[33]               $ 0.3              
Fair value [2],[9],[23],[32],[33]               $ (0.3)              
Investment, Identifier [Axis]: Australis Maritime, Common Stock, Transportation                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 48,936,056 [15],[29] 48,936,056 [15],[29] 48,936,056 [15],[29] 48,936,056 [15],[29] 48,936,056 [15],[29] 48,936,056 [15],[29] 48,936,056 [15],[29] 46,781,830 [6],[24],[32] 46,781,830 [6],[24],[32] 46,781,830 [6],[24],[32] 46,781,830 [6],[24],[32] 46,781,830 [6],[24],[32] 46,781,830 [6],[24],[32] 46,781,830 [6],[24],[32]  
Amortized cost $ 47.6 [15],[29]             $ 45.1 [24],[32]              
Fair value (49.3) [3],[15],[29]             (46.7) [2],[24],[32]              
Investment, Identifier [Axis]: Avenue One PropCo, Private Equity                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (31.0)             0.0              
Investment, Identifier [Axis]: Avenue One PropCo, Private Equity, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [15],[28],[29],[30] 30,064,353 30,064,353 30,064,353 30,064,353 30,064,353 30,064,353 30,064,353                
Amortized cost [15],[28],[29],[30] $ 30.1                            
Fair value [3],[15],[28],[29],[30] (31.0)                            
Investment, Identifier [Axis]: Avida Holding AB, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (42.6)             $ (52.3)             (38.3)
Investment, Identifier [Axis]: Avida Holding AB, Common Stock, Diversified Financials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 405,023,756 [15],[28],[29],[30] 405,023,756 [15],[28],[29],[30] 405,023,756 [15],[28],[29],[30] 405,023,756 [15],[28],[29],[30] 405,023,756 [15],[28],[29],[30] 405,023,756 [15],[28],[29],[30] 405,023,756 [15],[28],[29],[30] 405,023,756 [6],[23],[24],[31],[32] 405,023,756 [6],[23],[24],[31],[32] 405,023,756 [6],[23],[24],[31],[32] 405,023,756 [6],[23],[24],[31],[32] 405,023,756 [6],[23],[24],[31],[32] 405,023,756 [6],[23],[24],[31],[32] 405,023,756 [6],[23],[24],[31],[32]  
Amortized cost $ 44.6 [15],[28],[29],[30]             $ 44.6 [23],[24],[31],[32]              
Fair value $ (42.6) [3],[15],[28],[29],[30]             $ (52.3) [2],[23],[24],[31],[32]              
Investment, Identifier [Axis]: AxiomSL Ltd, Senior Secured Loans—First Lien, Software & Services, Maturing December 3, 2025                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 2.5              
Amortized cost [5]               2.4              
Fair value [2],[5]               $ (2.4)              
Investment, Identifier [Axis]: AxiomSL Ltd, Senior Secured Loans—First Lien, Software & Services, Maturing December 3, 2027 -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[38],[39],[43]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [32],[38],[39],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[38],[39],[43]               $ 35.1              
Amortized cost [32],[38],[39],[43]               34.4              
Fair value [2],[32],[38],[39],[43]               $ (34.4)              
Investment, Identifier [Axis]: AxiomSL Ltd, Senior Secured Loans—First Lien, Software & Services, Maturing December 3, 2027- 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 2.3              
Amortized cost [5]               2.3              
Fair value [2],[5]               $ (2.2)              
Investment, Identifier [Axis]: AxiomSL Ltd, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[18],[19],[40] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [15],[18],[19],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[18],[19],[40] $ 34.7                            
Amortized cost [15],[18],[19],[40] 34.1                            
Fair value [3],[15],[18],[19],[40] $ (33.7)                            
Investment, Identifier [Axis]: AxiomSL Ltd, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 2.5                            
Amortized cost [4] 2.4                            
Fair value [3],[4] $ (2.4)                            
Investment, Identifier [Axis]: AxiomSL Ltd, Software & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 2.3                            
Amortized cost [4] 2.3                            
Fair value [3],[4] $ (2.2)                            
Investment, Identifier [Axis]: BGB Group LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               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%  
Principal amount               $ 48.5              
Amortized cost               48.2              
Fair value               $ (48.3)              
Investment, Identifier [Axis]: BGB Group LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 54.4                            
Amortized cost 54.0                            
Fair value $ (53.0)                            
Investment, Identifier [Axis]: BGB Group LLC, Media & Entertainment 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[14],[16],[18],[19],[40] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [13],[14],[16],[18],[19],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[14],[16],[17],[18],[19],[40] $ 111.1                            
Amortized cost [13],[14],[16],[18],[19],[40] 110.3                            
Fair value [3],[13],[14],[16],[18],[19],[40] $ (108.4)                            
Investment, Identifier [Axis]: BGB Group LLC, Media & Entertainment 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 19.9                            
Amortized cost [4] 19.9                            
Fair value [3],[4] $ (19.5)                            
Investment, Identifier [Axis]: BGB Group LLC, Senior Secured Loans—First Lien, Media & Entertainment -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[9],[10],[32],[38],[39],[43]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [8],[9],[10],[32],[38],[39],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[8],[9],[10],[32],[38],[39],[43]               $ 118.6              
Amortized cost [8],[9],[10],[32],[38],[39],[43]               117.5              
Fair value [2],[8],[9],[10],[32],[38],[39],[43]               $ (118.0)              
Investment, Identifier [Axis]: BGB Group LLC, Senior Secured Loans—First Lien, Media & Entertainment -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 19.9              
Amortized cost [5]               19.9              
Fair value [2],[5]               $ (19.8)              
Investment, Identifier [Axis]: Bank of Ireland, Class B Credit Linked Floating Rate Note, Banks                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [7],[24],[45]               11.85% 11.85% 11.85% 11.85% 11.85% 11.85% 11.85%  
Principal amount [6],[24],[45]               $ 14.7              
Amortized cost [24],[45]               14.7              
Fair value [2],[24],[45]               $ (14.7)              
Investment, Identifier [Axis]: Bankers Healthcare Group LLC, Term Loan, Diversified Financials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[29] 3.93% 3.93% 3.93% 3.93% 3.93% 3.93% 3.93%                
Base rate floor [15],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount [15],[17],[29] $ 11.3                            
Amortized cost [15],[29] 11.3                            
Fair value [3],[15],[29] $ (11.3)                            
Investment, Identifier [Axis]: Barbri Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 47.2             $ 47.7              
Amortized cost 47.3             47.7              
Fair value $ (46.9)             $ (47.7)              
Investment, Identifier [Axis]: Barbri Inc, Consumer Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[14],[18],[19],[40] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [13],[14],[18],[19],[40] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[14],[17],[18],[19],[40] $ 61.5                            
Amortized cost [13],[14],[18],[19],[40] 57.7                            
Fair value [3],[13],[14],[18],[19],[40] $ (61.0)                            
Investment, Identifier [Axis]: Barbri Inc, Consumer Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [13],[14],[15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[14],[15],[17] $ 70.3                            
Amortized cost [13],[14],[15] 70.0                            
Fair value [3],[13],[14],[15] $ (69.7)                            
Investment, Identifier [Axis]: Barbri Inc, Consumer Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 9.1                            
Amortized cost [4] 9.1                            
Fair value [3],[4] $ (9.1)                            
Investment, Identifier [Axis]: Barbri Inc, Senior Secured Loans—First Lien, Consumer Services, Maturing April 28, 2028                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[9],[32],[38],[39],[43]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [8],[9],[32],[38],[39],[43]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[8],[9],[32],[38],[39],[43]               $ 92.4              
Amortized cost [8],[9],[32],[38],[39],[43]               88.1              
Fair value [2],[8],[9],[32],[38],[39],[43]               $ (92.4)              
Investment, Identifier [Axis]: Barbri Inc, Senior Secured Loans—First Lien, Consumer Services, Maturing April 30, 2028 - 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Base rate floor [8],[9]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[8],[9]               $ 35.1              
Amortized cost [8],[9]               34.8              
Fair value [2],[8],[9]               $ (34.8)              
Investment, Identifier [Axis]: Barbri Inc, Senior Secured Loans—First Lien, Consumer Services, Maturing April 30, 2028 -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 14.8              
Amortized cost [5]               14.8              
Fair value [2],[5]               $ (14.6)              
Investment, Identifier [Axis]: BearCom Acquisition Corp 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Interest rate, paid in kind 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 $ 2.2                         $ 14.4  
Amortized cost 2.2             $ 10.5              
Fair value $ (2.2)             $ (11.0)              
Investment, Identifier [Axis]: BearCom Acquisition Corp 1 | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Investment, Identifier [Axis]: BearCom Acquisition Corp 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Interest rate, paid in kind 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             $ 14.3             $ 1.3  
Amortized cost $ 10.6             $ 1.0              
Fair value $ (10.3)             $ (1.0)              
Investment, Identifier [Axis]: BearCom Acquisition Corp 2 | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Investment, Identifier [Axis]: BearCom Acquisition Corp 3 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount             $ 1.3                
Amortized cost $ 1.0                            
Fair value (1.0)                            
Investment, Identifier [Axis]: BearCom Acquisition Corp L+600 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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               $ 2.2              
Amortized cost               2.2              
Fair value               $ (2.1)              
Investment, Identifier [Axis]: Belk Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[32],[42]               10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%  
Principal amount [6],[20],[23],[32],[42]               $ 25.5              
Amortized cost [20],[23],[32],[42]               4.2              
Fair value               $ (6.7) [2],[20],[23],[32],[42]             0.0
Investment, Identifier [Axis]: Belk Inc | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[32],[42]               10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%  
Investment, Identifier [Axis]: Belk Inc 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (8.8)             $ (49.2)             0.0
Investment, Identifier [Axis]: Belk Inc 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 1.00% 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 $ 0.6             $ 0.6              
Amortized cost 0.6             0.6              
Fair value (0.6)             (0.6)              
Investment, Identifier [Axis]: Belk Inc 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (19.4)             $ (21.9)             0.0
Investment, Identifier [Axis]: Belk Inc 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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%  
Interest rate, paid in kind 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%  
Principal amount $ 3.1             $ 2.9              
Amortized cost 1.7             1.5              
Fair value $ (0.4)             $ (2.1)              
Investment, Identifier [Axis]: Belk Inc 2 | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 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%  
Investment, Identifier [Axis]: Belk Inc 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (3.3)             $ (6.7)              
Investment, Identifier [Axis]: Belk Inc, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ 0.0             0.0
Investment, Identifier [Axis]: Belk Inc, Common Stock | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 381 381 381 381 381 381 381                
Amortized cost $ 0.0                            
Fair value $ 0.0                            
Investment, Identifier [Axis]: Belk Inc, Common Stock 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares               381 381 381 381 381 381 381  
Amortized cost               $ 0.0              
Fair value               $ 0.0              
Investment, Identifier [Axis]: Belk Inc, Common Stock, Retailing                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 94,950 [15],[28],[41] 94,950 [15],[28],[41] 94,950 [15],[28],[41] 94,950 [15],[28],[41] 94,950 [15],[28],[41] 94,950 [15],[28],[41] 94,950 [15],[28],[41] 94,950 [23],[42],[46],[50] 94,950 [23],[42],[46],[50] 94,950 [23],[42],[46],[50] 94,950 [23],[42],[46],[50] 94,950 [23],[42],[46],[50] 94,950 [23],[42],[46],[50] 94,950 [23],[42],[46],[50]  
Amortized cost $ 0.0 [15],[28],[41]             $ 0.0 [23],[42],[46],[50]              
Fair value $ 0.0 [1],[15],[28],[41]             $ 0.0 [2],[23],[42],[46],[50]              
Investment, Identifier [Axis]: Belk Inc, Retailing 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[37],[41] 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%                
Base rate floor [15],[37],[41] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[37],[41] $ 21.9                            
Amortized cost [15],[37],[41] 21.8                            
Fair value [3],[15],[37],[41] $ (19.4)                            
Investment, Identifier [Axis]: Belk Inc, Retailing 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[25],[28],[37],[41] 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%                
Interest rate, paid in kind [12],[15],[25],[28],[37],[41] 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%                
Principal amount [15],[17],[25],[28],[37],[41] $ 71.0                            
Amortized cost [15],[25],[28],[37],[41] 42.5                            
Fair value [3],[15],[25],[28],[37],[41] $ (8.8)                            
Investment, Identifier [Axis]: Belk Inc, Retailing 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15],[25],[28],[37],[41] 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%                
Investment, Identifier [Axis]: Belk Inc, Retailing 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%                
Principal amount [15],[17],[25],[28],[41] $ 28.2                            
Amortized cost [15],[25],[28],[41] 4.2                            
Fair value [3],[15],[25],[28],[41] $ (3.3)                            
Investment, Identifier [Axis]: Belk Inc, Retailing 3 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%                
Investment, Identifier [Axis]: Belk Inc, Senior Secured Loans—First Lien, Retailing, Maturing July 31, 2025 -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[36],[42]               7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%  
Base rate floor [32],[36],[42]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[36],[42]               $ 21.9              
Amortized cost [32],[36],[42]               21.7              
Fair value [2],[32],[36],[42]               $ (21.9)              
Investment, Identifier [Axis]: Belk Inc, Senior Secured Loans—First Lien, Retailing, Maturing July 31, 2025 -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[36],[42]               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Interest rate, paid in kind [32],[36],[42]               8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%  
Principal amount [6],[32],[36],[42]               $ 66.7              
Amortized cost [32],[36],[42]               40.2              
Fair value [2],[32],[36],[42]               $ (49.2)              
Investment, Identifier [Axis]: Belk Inc, Senior Secured Loans—First Lien, Retailing, Maturing July 31, 2025 -2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32],[36],[42]               8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%  
Investment, Identifier [Axis]: Big Bus Tours Ltd 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%                
Interest rate, paid in kind 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%  
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 $ 10.7             $ 16.4              
Amortized cost 10.7             16.4              
Fair value $ (8.8)             $ (10.3)              
Investment, Identifier [Axis]: Big Bus Tours Ltd 1 | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind               8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%  
Investment, Identifier [Axis]: Big Bus Tours Ltd 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%                
Interest rate, paid in kind 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%  
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 | €       € 12.6             € 11.5        
Amortized cost $ 14.0             $ 12.9              
Fair value $ (11.0)             $ (8.3)              
Investment, Identifier [Axis]: Big Bus Tours Ltd 2 | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind               8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%  
Investment, Identifier [Axis]: Big Bus Tours Ltd 3 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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 $ 7.2                            
Amortized cost 7.2                            
Fair value (5.9)                            
Investment, Identifier [Axis]: Borden (New Dairy Opco) 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[42]               7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%  
Interest rate, paid in kind [32],[42]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base rate floor [32],[42]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[42]               $ 42.0              
Amortized cost [32],[42]               40.2              
Fair value 0.0             $ (42.0) [2],[32],[42]              
Investment, Identifier [Axis]: Borden (New Dairy Opco) 1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32],[42]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Investment, Identifier [Axis]: Borden (New Dairy Opco) 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[42]               2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%  
Base rate floor [32],[42]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[42]               $ 9.0              
Amortized cost [32],[42]               8.4              
Fair value 0.0             (9.0) [2],[32],[42]              
Investment, Identifier [Axis]: Borden (New Dairy Opco) 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               (9.0)             (7.6)
Investment, Identifier [Axis]: Borden (New Dairy Opco) 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               (42.0)             (16.8)
Investment, Identifier [Axis]: Borden (New Dairy Opco), Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (4.8)             $ (7.7)             (3.2)
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 [28],[41],[47],[51] 11,167,000 [28],[41],[47],[51] 11,167,000 [28],[41],[47],[51] 11,167,000 [28],[41],[47],[51] 11,167,000 [28],[41],[47],[51] 11,167,000 [28],[41],[47],[51] 11,167,000 [28],[41],[47],[51] 11,167,000 [23],[42],[46],[50] 11,167,000 [23],[42],[46],[50] 11,167,000 [23],[42],[46],[50] 11,167,000 [23],[42],[46],[50] 11,167,000 [23],[42],[46],[50] 11,167,000 [23],[42],[46],[50] 11,167,000 [23],[42],[46],[50]  
Amortized cost $ 9.1 [28],[41],[47],[51]             $ 9.1 [23],[42],[46],[50]              
Fair value (4.8) [1],[28],[41],[47],[51]             $ (7.7) [2],[23],[42],[46],[50]              
Investment, Identifier [Axis]: Borden Dairy Co                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [20],[23],[32],[42]               8.25% 8.25% 8.25% 8.25% 8.25% 8.25% 8.25%  
Base rate floor [20],[23],[32],[42]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[20],[23],[32],[42]               $ 65.0              
Amortized cost [20],[23],[32],[42]               25.4              
Fair value $ 0.0             $ 0.0 [2],[20],[23],[32],[42]             0.0
Investment, Identifier [Axis]: Bowery Farming Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 75.0              
Amortized cost [32]               74.3              
Fair value [2],[32]               $ (69.3)              
Investment, Identifier [Axis]: Bowery Farming Inc, Food, Beverage & Tobacco                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 75.0                            
Amortized cost [15] 74.4                            
Fair value [3],[15] $ (70.3)                            
Investment, Identifier [Axis]: Bowery Farming Inc, Warrants, Food, Beverage & Tobacco                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 161,828 [15],[28] 161,828 [15],[28] 161,828 [15],[28] 161,828 [15],[28] 161,828 [15],[28] 161,828 [15],[28] 161,828 [15],[28] 161,828 [23],[32] 161,828 [23],[32] 161,828 [23],[32] 161,828 [23],[32] 161,828 [23],[32] 161,828 [23],[32] 161,828 [23],[32]  
Amortized cost $ 0.0 [15],[28]             $ 0.0 [23],[32]              
Fair value $ (2.5) [1],[15],[28]             $ (5.2) [2],[23],[32]              
Investment, Identifier [Axis]: Bugaboo International BV | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%  
Interest rate, paid in kind               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base rate floor               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | €                     € 35.0        
Amortized cost               $ 40.8              
Fair value               $ (39.8)              
Investment, Identifier [Axis]: Bugaboo International BV | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind               7.80% 7.80% 7.80% 7.80% 7.80% 7.80% 7.80%  
Investment, Identifier [Axis]: Bugaboo International BV | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%                
Interest rate, paid in kind 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | €       € 35.0                      
Amortized cost $ 41.0                            
Fair value $ (37.4)                            
Investment, Identifier [Axis]: Bugaboo International BV | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 7.80% 7.80% 7.80% 7.80% 7.80% 7.80% 7.80%                
Investment, Identifier [Axis]: Byrider Finance LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[52]               10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%  
Interest rate, paid in kind [32],[52]               0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Base rate floor [32],[52]               1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30%  
Principal amount [6],[32],[52]               $ 54.3              
Amortized cost [32],[52]               52.8              
Fair value [2],[32],[52]               $ (54.4)              
Investment, Identifier [Axis]: Byrider Finance LLC | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32],[52]               0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Investment, Identifier [Axis]: Byrider Finance LLC, Private Equity, Automobiles & Components                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [15],[28],[53] 54,407 54,407 54,407 54,407 54,407 54,407 54,407                
Amortized cost [15],[28],[53] $ 0.0                            
Fair value [3],[15],[28],[53] $ 0.0                            
Investment, Identifier [Axis]: Byrider Finance LLC, Structured Mezzanine, Automobiles & Components                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5],[7]               10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50%  
Base rate floor [5]               0.30% 0.30% 0.30% 0.30% 0.30% 0.30% 0.30%  
Principal amount [5],[6]               $ 23.0              
Amortized cost [5]               23.0              
Fair value [2],[5]               $ (23.0)              
Investment, Identifier [Axis]: Byrider Finance LLC, Structured Mezzanine, Automobiles & Components 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50%                
Base rate floor [15] 0.30% 0.30% 0.30% 0.30% 0.30% 0.30% 0.30%                
Principal amount [15],[17] $ 16.2                            
Amortized cost [15] 16.2                            
Fair value [3],[15] $ (16.1)                            
Investment, Identifier [Axis]: Byrider Finance LLC, Structured Mezzanine, Automobiles & Components 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50%                
Base rate floor [4] 0.30% 0.30% 0.30% 0.30% 0.30% 0.30% 0.30%                
Principal amount [4],[17] $ 6.8                            
Amortized cost [4] 6.8                            
Fair value [3],[4] $ (6.8)                            
Investment, Identifier [Axis]: Byrider Finance LLC, Term Loan, Automobiles & Components                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [15],[28],[53] 5,000,000 5,000,000 5,000,000 5,000,000 5,000,000 5,000,000 5,000,000                
Amortized cost [15],[28],[53] $ 5.0                            
Fair value [3],[15],[28],[53] $ (5.0)                            
Investment, Identifier [Axis]: CDS US Intermediate Holdings Inc, Warrant, Media & Entertainment                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 2,023,714 [15],[28],[29] 2,023,714 [15],[28],[29] 2,023,714 [15],[28],[29] 2,023,714 [15],[28],[29] 2,023,714 [15],[28],[29] 2,023,714 [15],[28],[29] 2,023,714 [15],[28],[29] 2,023,714 [23],[24],[32] 2,023,714 [23],[24],[32] 2,023,714 [23],[24],[32] 2,023,714 [23],[24],[32] 2,023,714 [23],[24],[32] 2,023,714 [23],[24],[32] 2,023,714 [23],[24],[32]  
Amortized cost $ 0.0 [15],[28],[29]             $ 0.0 [23],[24],[32]              
Fair value $ (4.0) [1],[15],[28],[29]             $ 0.0 [2],[23],[24],[32]              
Investment, Identifier [Axis]: CFC Underwriting Ltd | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%                
Interest rate, paid in kind 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount $ 39.5                            
Amortized cost 38.3                            
Fair value $ (39.2)                            
Investment, Identifier [Axis]: CFC Underwriting Ltd | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80%                
Investment, Identifier [Axis]: CFC Underwriting Ltd, Insurance                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12],[29] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Interest rate, paid in kind [4],[12],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor [4],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | £ [4],[17],[29]         £ 4.7                    
Amortized cost [4],[29] $ 5.7                            
Fair value [3],[4],[29] $ (5.7)                            
Investment, Identifier [Axis]: CFC Underwriting Ltd, Insurance | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [4],[12],[29] 2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80%                
Investment, Identifier [Axis]: CSafe Global 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 0.80% 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 $ 59.4             $ 60.0              
Amortized cost 59.3             59.9              
Fair value $ (59.4)             $ (60.0)              
Investment, Identifier [Axis]: CSafe Global 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 0.80% 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 $ 17.3             $ 17.5              
Amortized cost 17.3             17.5              
Fair value $ (17.3)             $ (17.5)              
Investment, Identifier [Axis]: CSafe Global, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[14],[15],[16],[18],[19],[40] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [13],[14],[15],[16],[18],[19],[40] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[14],[15],[16],[17],[18],[19],[40] $ 186.8                            
Amortized cost [13],[14],[15],[16],[18],[19],[40] 181.5                            
Fair value [3],[13],[14],[15],[16],[18],[19],[40] $ (186.8)                            
Investment, Identifier [Axis]: CSafe Global, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount | £ [15],[17]         £ 27.2                    
Amortized cost [15] $ 35.9                            
Fair value [3],[15] $ (32.8)                            
Investment, Identifier [Axis]: CSafe Global, Capital Goods 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 11.8                            
Amortized cost [15] 11.8                            
Fair value [3],[15] $ (11.8)                            
Investment, Identifier [Axis]: CSafe Global, Capital Goods 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 34.9                            
Amortized cost [4] 34.9                            
Fair value [3],[4] $ (34.7)                            
Investment, Identifier [Axis]: CSafe Global, Senior Secured Loans—First Lien, Capital Goods, August 13, 2028                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[32]               $ 11.9              
Amortized cost [32]               11.9              
Fair value [2],[32]               $ (11.9)              
Investment, Identifier [Axis]: CSafe Global, Senior Secured Loans—First Lien, Capital Goods, December 23, 2026                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 34.9              
Amortized cost [5]               34.9              
Fair value [2],[5]               $ (34.6)              
Investment, Identifier [Axis]: CSafe Global, Senior Secured Loans—First Lien, Capital Goods, December 23, 2027 -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[9],[10],[32],[38],[39],[43]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [8],[9],[10],[32],[38],[39],[43]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[8],[9],[10],[32],[38],[39],[43]               $ 188.7              
Amortized cost [8],[9],[10],[32],[38],[39],[43]               182.5              
Fair value [2],[8],[9],[10],[32],[38],[39],[43]               $ (188.7)              
Investment, Identifier [Axis]: CSafe Global, Senior Secured Loans—First Lien, Capital Goods, December 23, 2027 -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount | £ [6],[32]                       £ 27.4      
Amortized cost [32]               $ 36.3              
Fair value [2],[32]               $ (37.1)              
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 [15],[28] 5,892 [15],[28] 5,892 [15],[28] 5,892 [15],[28] 5,892 [15],[28] 5,892 [15],[28] 5,892 [15],[28] 5,892 [23],[32] 5,892 [23],[32] 5,892 [23],[32] 5,892 [23],[32] 5,892 [23],[32] 5,892 [23],[32] 5,892 [23],[32]  
Amortized cost $ 0.7 [15],[28]             $ 0.7 [23],[32]              
Fair value $ 0.0 [1],[15],[28]             $ 0.0 [2],[23],[32]              
Investment, Identifier [Axis]: Caldic BV, Retailing 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[29],[37] 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50%                
Base rate floor [15],[29],[37] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | € [15],[17],[29],[37]       € 0.8                      
Amortized cost [15],[29],[37] $ 0.9                            
Fair value [3],[15],[29],[37] $ (0.8)                            
Investment, Identifier [Axis]: Caldic BV, Retailing 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[29],[37] 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75%                
Base rate floor [15],[29],[37] 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount [15],[17],[29],[37] $ 1.4                            
Amortized cost [15],[29],[37] 1.4                            
Fair value [3],[15],[29],[37] $ (1.4)                            
Investment, Identifier [Axis]: Caldic BV, Retailing 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25%                
Base rate floor [15],[29] 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount [15],[17],[29] $ 40.0                            
Amortized cost [15],[29] 39.0                            
Fair value [3],[15],[29] $ (38.2)                            
Investment, Identifier [Axis]: Callodine Commercial Finance LLC, 2L Term Loan A, Diversified Financials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 9.00% [12],[15] 9.00% [12],[15] 9.00% [12],[15] 9.00% [12],[15] 9.00% [12],[15] 9.00% [12],[15] 9.00% [12],[15] 9.00% [7],[32] 9.00% [7],[32] 9.00% [7],[32] 9.00% [7],[32] 9.00% [7],[32] 9.00% [7],[32] 9.00% [7],[32]  
Base rate floor 1.00% [15] 1.00% [15] 1.00% [15] 1.00% [15] 1.00% [15] 1.00% [15] 1.00% [15] 1.00% [32] 1.00% [32] 1.00% [32] 1.00% [32] 1.00% [32] 1.00% [32] 1.00% [32]  
Principal amount $ 125.0 [15],[17]             $ 125.0 [6],[32]              
Amortized cost 119.3 [15]             118.0 [32]              
Fair value $ (125.3) [3],[15]             $ (125.6) [2],[32]              
Investment, Identifier [Axis]: Callodine Commercial Finance LLC, 2L Term Loan B, Diversified Financials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5],[7]               9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 40.3              
Amortized cost [5]               40.3              
Fair value [2],[5]               $ (40.5)              
Investment, Identifier [Axis]: Callodine Commercial Finance LLC, 2L Term Loan B, Diversified Financials 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 12.0                            
Amortized cost [15] 12.0                            
Fair value [3],[15] $ (12.0)                            
Investment, Identifier [Axis]: Callodine Commercial Finance LLC, 2L Term Loan B, Diversified Financials 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 36.1                            
Amortized cost [4] 36.1                            
Fair value [3],[4] $ (36.1)                            
Investment, Identifier [Axis]: Capital Automotive LP, Private Equity, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 21,640,936 [15],[29] 21,640,936 [15],[29] 21,640,936 [15],[29] 21,640,936 [15],[29] 21,640,936 [15],[29] 21,640,936 [15],[29] 21,640,936 [15],[29] 21,640,936 [6],[24],[32] 21,640,936 [6],[24],[32] 21,640,936 [6],[24],[32] 21,640,936 [6],[24],[32] 21,640,936 [6],[24],[32] 21,640,936 [6],[24],[32] 21,640,936 [6],[24],[32]  
Amortized cost $ 23.7 [15],[29]             $ 23.7 [24],[32]              
Fair value $ (27.0) [3],[15],[29]             (28.1) [2],[24],[32]              
Investment, Identifier [Axis]: Capital Automotive LP, Structured Mezzanine, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [6],[24],[32]               42.7              
Number of shares | shares [15],[29] 42,400,000 42,400,000 42,400,000 42,400,000 42,400,000 42,400,000 42,400,000                
Amortized cost $ 41.7 [15],[29]             41.9 [24],[32]              
Fair value $ (42.4) [3],[15],[29]             $ (42.7) [2],[24],[32]              
Investment, Identifier [Axis]: Caprock Midstream LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               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%  
Principal amount               $ 13.3              
Amortized cost               13.0              
Fair value               $ (13.2)              
Investment, Identifier [Axis]: Catalina Marketing Corp, Common Stock, Media & Entertainment                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 6,522 [15],[28] 6,522 [15],[28] 6,522 [15],[28] 6,522 [15],[28] 6,522 [15],[28] 6,522 [15],[28] 6,522 [15],[28] 6,522 [23],[32] 6,522 [23],[32] 6,522 [23],[32] 6,522 [23],[32] 6,522 [23],[32] 6,522 [23],[32] 6,522 [23],[32]  
Amortized cost $ 0.0 [15],[28]             $ 0.0 [23],[32]              
Fair value $ 0.0 [1],[15],[28]             $ 0.0 [2],[23],[32]              
Investment, Identifier [Axis]: Cengage Learning, Inc, Common Stock, Media & Entertainment                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 227,802 [15],[28] 227,802 [15],[28] 227,802 [15],[28] 227,802 [15],[28] 227,802 [15],[28] 227,802 [15],[28] 227,802 [15],[28] 227,802 [23],[32] 227,802 [23],[32] 227,802 [23],[32] 227,802 [23],[32] 227,802 [23],[32] 227,802 [23],[32] 227,802 [23],[32]  
Amortized cost $ 7.6 [15],[28]             $ 7.5 [23],[32]              
Fair value $ (3.6) [1],[15],[28]             (4.2) [2],[23],[32]              
Investment, Identifier [Axis]: Charlotte Russe Inc, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               $ 0.0             0.0
Investment, Identifier [Axis]: Cimarron Energy Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [20],[23],[32]               9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%  
Base rate floor [20],[23],[32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[20],[23],[32]               $ 7.5              
Amortized cost [20],[23],[32]               5.5              
Fair value [2],[20],[23],[32]               $ (3.6)              
Investment, Identifier [Axis]: Cimarron Energy Inc, Common Stock, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 4,302,293 [15],[28] 4,302,293 [15],[28] 4,302,293 [15],[28] 4,302,293 [15],[28] 4,302,293 [15],[28] 4,302,293 [15],[28] 4,302,293 [15],[28] 4,302,293 [23],[32] 4,302,293 [23],[32] 4,302,293 [23],[32] 4,302,293 [23],[32] 4,302,293 [23],[32] 4,302,293 [23],[32] 4,302,293 [23],[32]  
Amortized cost $ 0.0 [15],[28]             $ 0.0 [23],[32]              
Fair value $ 0.0 [1],[15],[28]             $ (0.0) [2],[23],[32]              
Investment, Identifier [Axis]: Cimarron Energy Inc, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[25],[28] 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%                
Base rate floor [15],[25],[28] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[25],[28] $ 7.5                            
Amortized cost [15],[25],[28] 4.8                            
Fair value [3],[15],[25],[28] $ (3.7)                            
Investment, Identifier [Axis]: Cimarron Energy Inc, Participation Option, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 25,000,000 [15],[28] 25,000,000 [15],[28] 25,000,000 [15],[28] 25,000,000 [15],[28] 25,000,000 [15],[28] 25,000,000 [15],[28] 25,000,000 [15],[28] 25,000,000 [23],[32] 25,000,000 [23],[32] 25,000,000 [23],[32] 25,000,000 [23],[32] 25,000,000 [23],[32] 25,000,000 [23],[32] 25,000,000 [23],[32]  
Amortized cost $ 0.0 [15],[28]             $ 0.0 [23],[32]              
Fair value $ 0.0 [1],[15],[28]             $ 0.0 [2],[23],[32]              
Investment, Identifier [Axis]: Cision Ltd 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 3.8                            
Amortized cost 3.4                            
Fair value $ (2.4)                            
Investment, Identifier [Axis]: Clarience Technologies LLC, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[15],[16],[18],[34],[40] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [13],[15],[16],[18],[34],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[15],[16],[17],[18],[34],[40] $ 294.0                            
Amortized cost [13],[15],[16],[18],[34],[40] 284.6                            
Fair value [3],[13],[15],[16],[18],[34],[40] $ (287.9)                            
Investment, Identifier [Axis]: Clarience Technologies LLC, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 25.4                            
Amortized cost [4] 25.3                            
Fair value [3],[4] $ (24.9)                            
Investment, Identifier [Axis]: Clarience Technologies LLC, Senior Secured Loans—First Lien, Capital Goods, December 13, 2024                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 10.8              
Amortized cost [5]               10.8              
Fair value [2],[5]               $ (11.1)              
Investment, Identifier [Axis]: Clarience Technologies LLC, Senior Secured Loans—First Lien, Capital Goods, December 14, 2026                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[10],[32],[33],[39],[43]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [8],[10],[32],[33],[39],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[8],[10],[32],[33],[39],[43]               $ 268.0              
Amortized cost [8],[10],[32],[33],[39],[43]               257.2              
Fair value [2],[8],[10],[32],[33],[39],[43]               $ (270.7)              
Investment, Identifier [Axis]: Clarience Technologies LLC, Senior Secured Loans—First Lien, Capital Goods, December 31, 2026 -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 18.1              
Amortized cost [32]               17.6              
Fair value [2],[32]               $ (18.4)              
Investment, Identifier [Axis]: Clarience Technologies LLC, Senior Secured Loans—First Lien, Capital Goods, December 31, 2026 -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 25.4              
Amortized cost [5]               25.2              
Fair value [2],[5]               (25.4)              
Investment, Identifier [Axis]: ClubCorp Club Operations Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [6],[32],[36]               37.3              
Amortized cost [32],[36]               35.4              
Fair value [2],[32],[36]               $ (35.7)              
Investment, Identifier [Axis]: ClubCorp Club Operations Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 31.9                            
Amortized cost 29.9                            
Fair value $ (28.9)                            
Investment, Identifier [Axis]: Community Brands Inc, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 32.7                            
Amortized cost [15] 32.1                            
Fair value [3],[15] $ (31.6)                            
Investment, Identifier [Axis]: Community Brands Inc, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 3.9                            
Amortized cost [4] 3.8                            
Fair value [3],[4] $ (3.7)                            
Investment, Identifier [Axis]: Community Brands Inc, Software & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 1.9                            
Amortized cost [4] 1.9                            
Fair value [3],[4] $ (1.9)                            
Investment, Identifier [Axis]: Connecticut Avenue Securities Trust 2022-R08, Structured Mezzanine | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 2.3                            
Amortized cost 2.3                            
Fair value (2.4)                            
Investment, Identifier [Axis]: Constellis Holdings LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[42],[43]               11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%  
Interest rate, paid in kind [32],[42],[43]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base rate floor [32],[42],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[42],[43]               $ 13.5              
Amortized cost [32],[42],[43]               12.5              
Fair value [2],[32],[42],[43]               $ (12.0)              
Investment, Identifier [Axis]: Constellis Holdings LLC | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32],[42],[43]               10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%  
Investment, Identifier [Axis]: Constellis Holdings LLC 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[42]               7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%  
Base rate floor [32],[42]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[42]               $ 15.0              
Amortized cost [32],[42]               14.0              
Fair value (15.0)             (15.0) [2],[32],[42]             0.0
Investment, Identifier [Axis]: Constellis Holdings LLC 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (13.5)             (12.0)             0.0
Investment, Identifier [Axis]: Constellis Holdings LLC, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[41] 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%                
Base rate floor [15],[41] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[41] $ 15.0                            
Amortized cost [15],[41] 14.4                            
Fair value [3],[15],[41] $ (15.0)                            
Investment, Identifier [Axis]: Constellis Holdings LLC, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%                
Interest rate, paid in kind [12] 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%                
Base rate floor [15],[41] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[41] $ 13.5                            
Amortized cost [15],[41] 12.8                            
Fair value [3],[15],[41] $ (13.5)                            
Investment, Identifier [Axis]: Constellis Holdings LLC, Capital Goods 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Investment, Identifier [Axis]: Constellis Holdings LLC, Private Equity                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (6.3)             $ (0.2)             $ 0.0
Investment, Identifier [Axis]: Constellis Holdings LLC, Private Equity, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 849,702 [15],[18],[28],[41] 849,702 [15],[18],[28],[41] 849,702 [15],[18],[28],[41] 849,702 [15],[18],[28],[41] 849,702 [15],[18],[28],[41] 849,702 [15],[18],[28],[41] 849,702 [15],[18],[28],[41] 849,702 [23],[32],[42],[43] 849,702 [23],[32],[42],[43] 849,702 [23],[32],[42],[43] 849,702 [23],[32],[42],[43] 849,702 [23],[32],[42],[43] 849,702 [23],[32],[42],[43] 849,702 [23],[32],[42],[43]  
Amortized cost $ 10.3 [15],[18],[28],[41]             $ 10.3 [23],[32],[42],[43]              
Fair value $ (6.3) [1],[15],[18],[28],[41]             $ (0.2) [2],[23],[32],[42],[43]              
Investment, Identifier [Axis]: Corsearch Intermediate Inc, Senior Secured Loans—First Lien, Software & Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[39]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [32],[39]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[39]               $ 30.1              
Amortized cost [32],[39]               28.3              
Fair value [2],[32],[39]               $ (30.1)              
Investment, Identifier [Axis]: Corsearch Intermediate Inc, Senior Secured Loans—First Lien, Software & Services -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 4.4              
Amortized cost [5]               4.4              
Fair value [2],[5]               (4.4)              
Investment, Identifier [Axis]: Corsearch Intermediate Inc, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[40] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [15],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[40] $ 30.1                            
Amortized cost [15],[40] 28.5                            
Fair value [3],[15],[40] $ (29.8)                            
Investment, Identifier [Axis]: Corsearch Intermediate Inc, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 4.4                            
Amortized cost [4] 4.4                            
Fair value [3],[4] $ (4.4)                            
Investment, Identifier [Axis]: Creation Technologies Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 2.3                            
Amortized cost 2.1                            
Fair value (1.8)                            
Investment, Identifier [Axis]: Credit Opportunities Partners JV, LLC 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value (1,428.3)             (1,396.2)              
Investment, Identifier [Axis]: Credit Opportunities Partners JV, LLC, Diversified Financials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount 1,637.3 [15],[17],[29],[30]             1,462.3 [6],[24],[31],[32]              
Amortized cost 1,571.7 [15],[29],[30]             1,396.7 [24],[31],[32]              
Fair value $ (1,428.3) [3],[15],[29],[30]             $ (1,396.2) [2],[24],[31],[32]              
Investment, Identifier [Axis]: Cubic Corp                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               7.63% 7.63% 7.63% 7.63% 7.63% 7.63% 7.63%  
Base rate floor [32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[32]               $ 54.8              
Amortized cost [32]               51.8              
Fair value [2],[32]               $ (55.6)              
Investment, Identifier [Axis]: Cubic Corp | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 10.0                            
Amortized cost 9.7                            
Fair value $ (9.1)                            
Investment, Identifier [Axis]: Cubic Corp 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 9.1             $ 9.2              
Amortized cost 9.1             9.2              
Fair value $ (7.7)             $ (9.2)              
Investment, Identifier [Axis]: Cubic Corp, Preferred Stock, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 11.00% [12],[15] 11.00% [12],[15] 11.00% [12],[15] 11.00% [12],[15] 11.00% [12],[15] 11.00% [12],[15] 11.00% [12],[15]               11.00% [7],[32]
Number of shares | shares 42,141,600 [15] 42,141,600 [15] 42,141,600 [15] 42,141,600 [15] 42,141,600 [15] 42,141,600 [15] 42,141,600 [15] 42,141,600 [32] 42,141,600 [32] 42,141,600 [32] 42,141,600 [32] 42,141,600 [32] 42,141,600 [32] 42,141,600 [32]  
Amortized cost $ 39.8 [15]             $ 39.6 [32]              
Fair value $ (34.7) [1],[15]             $ (42.3) [2],[32]              
Investment, Identifier [Axis]: Cubic Corp, Preferred Stock, Software & Services | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 11.00% [12],[15] 11.00% [12],[15] 11.00% [12],[15] 11.00% [12],[15] 11.00% [12],[15] 11.00% [12],[15] 11.00% [12],[15]               11.00% [7],[32]
Investment, Identifier [Axis]: Cubic Corp, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 7.63% 7.63% 7.63% 7.63% 7.63% 7.63% 7.63%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 44.8                            
Amortized cost [15] 42.2                            
Fair value [3],[15] $ (40.6)                            
Investment, Identifier [Axis]: DOC Generici Srl, Pharmaceuticals, Biotechnology & Life Sciences 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[29] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [15],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | € [15],[17],[29]       € 23.1                      
Amortized cost [15],[29] $ 22.5                            
Fair value [3],[15],[29] $ (24.1)                            
Investment, Identifier [Axis]: DOC Generici Srl, Pharmaceuticals, Biotechnology & Life Sciences 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12],[29] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [4],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | € [4],[17],[29]       € 2.4                      
Amortized cost [4],[29] $ 2.3                            
Fair value [3],[4],[29] $ (2.2)                            
Investment, Identifier [Axis]: Datatel Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 179.2              
Amortized cost [32]               170.1              
Fair value [2],[32]               $ (184.6)              
Investment, Identifier [Axis]: Dental Care Alliance Inc, Health Care Equipment & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[15],[18],[19],[40] 6.41% 6.41% 6.41% 6.41% 6.41% 6.41% 6.41%                
Base rate floor [13],[15],[18],[19],[40] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[15],[17],[18],[19],[40] $ 135.4                            
Amortized cost [13],[15],[18],[19],[40] 131.7                            
Fair value [3],[13],[15],[18],[19],[40] $ (132.7)                            
Investment, Identifier [Axis]: Dental Care Alliance Inc, Health Care Equipment & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 6.41% 6.41% 6.41% 6.41% 6.41% 6.41% 6.41%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 1.7                            
Amortized cost [4] 1.7                            
Fair value [3],[4] $ (1.6)                            
Investment, Identifier [Axis]: Dental Care Alliance Inc, Senior Secured Loans—First Lien, Health Care Equipment & Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[32],[38],[39],[43]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [8],[32],[38],[39],[43]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[8],[32],[38],[39],[43]               $ 90.3              
Amortized cost [8],[32],[38],[39],[43]               86.1              
Fair value [2],[8],[32],[38],[39],[43]               $ (90.4)              
Investment, Identifier [Axis]: Dental Care Alliance Inc, Senior Secured Loans—First Lien, Health Care Equipment & Services -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[32]               $ 8.7              
Amortized cost [32]               8.7              
Fair value [2],[32]               $ (8.7)              
Investment, Identifier [Axis]: Dental Care Alliance Inc, Senior Secured Loans—First Lien, Health Care Equipment & Services -3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 13.6              
Amortized cost [5]               13.6              
Fair value [2],[5]               $ (13.7)              
Investment, Identifier [Axis]: EIF Van Hook Holdings LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 0.00% 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 $ 7.2             $ 8.1              
Amortized cost 7.0             7.8              
Fair value $ (7.0)             $ (7.8)              
Investment, Identifier [Axis]: EaglePicher Technologies LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 0.4             $ 0.4              
Amortized cost 0.4             0.4              
Fair value $ (0.2)             $ (0.4)              
Investment, Identifier [Axis]: Eagleclaw Midstream Ventures LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               4.25% 4.25% 4.25% 4.25% 4.25% 4.25% 4.25%  
Base rate floor               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount               $ 11.1              
Amortized cost               10.6              
Fair value               $ (11.1)              
Investment, Identifier [Axis]: Element Materials Technology Group US Holdings Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [24],[32],[36]               3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50%  
Base rate floor [24],[32],[36]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[24],[32],[36]               $ 1.9              
Amortized cost [24],[32],[36]               1.9              
Fair value [2],[24],[32],[36]               $ (1.9)              
Investment, Identifier [Axis]: Element Materials Technology Group US Holdings Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount | £         £ 21.0                    
Amortized cost $ 23.0                            
Fair value $ (24.7)                            
Investment, Identifier [Axis]: Element Materials Technology Group US Holdings Inc, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[29],[37] 4.25% 4.25% 4.25% 4.25% 4.25% 4.25% 4.25%                
Base rate floor [15],[29],[37] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | € [15],[17],[29],[37]       € 0.3                      
Amortized cost [15],[29],[37] $ 0.4                            
Fair value [3],[15],[29],[37] $ (0.4)                            
Investment, Identifier [Axis]: Element Materials Technology Group US Holdings Inc, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[29],[37] 4.25% 4.25% 4.25% 4.25% 4.25% 4.25% 4.25%                
Base rate floor [15],[29],[37] 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount [15],[17],[29],[37] $ 1.4                            
Amortized cost [15],[29],[37] 1.4                            
Fair value [3],[15],[29],[37] $ (1.4)                            
Investment, Identifier [Axis]: Element Materials Technology Group US Holdings Inc, Commercial & Professional Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%                
Base rate floor [15],[29] 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount [15],[17],[29] $ 67.9                            
Amortized cost [15],[29] 66.5                            
Fair value [3],[15],[29] $ (64.6)                            
Investment, Identifier [Axis]: Element Materials Technology Group US Holdings Inc, Commercial & Professional Services 3 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%                
Investment, Identifier [Axis]: Ellucian Inc, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 179.2                            
Amortized cost [15] 170.9                            
Fair value [3],[15] $ (177.5)                            
Investment, Identifier [Axis]: Emerald Expositions Holding Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 1.4                            
Amortized cost 1.3                            
Fair value $ (1.4)                            
Investment, Identifier [Axis]: Encora Digital Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32]               9.80% 9.80% 9.80% 9.80% 9.80% 9.80% 9.80%  
Principal amount [6],[32]               $ 21.6              
Amortized cost [32]               20.9              
Fair value [2],[32]               $ (20.9)              
Investment, Identifier [Axis]: Encora Digital Inc | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32]               9.80% 9.80% 9.80% 9.80% 9.80% 9.80% 9.80%  
Investment, Identifier [Axis]: Encora Digital Inc 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Interest rate, paid in kind 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount $ 16.3                            
Amortized cost 15.9                            
Fair value $ (15.4)                            
Investment, Identifier [Axis]: Encora Digital Inc 1 | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 2.40% 2.40% 2.40% 2.40% 2.40% 2.40% 2.40%                
Investment, Identifier [Axis]: Encora Digital Inc, Senior Secured Loans—First Lien, Software & Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Interest rate, paid in kind [32]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base rate floor [32]               0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount [6],[32]               $ 81.3              
Amortized cost [32]               79.7              
Fair value [2],[32]               $ (79.7)              
Investment, Identifier [Axis]: Encora Digital Inc, Senior Secured Loans—First Lien, Software & Services -1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32]               2.40% 2.40% 2.40% 2.40% 2.40% 2.40% 2.40%  
Investment, Identifier [Axis]: Encora Digital Inc, Senior Secured Loans—First Lien, Software & Services -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [5]               0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount [5],[6]               $ 19.6              
Amortized cost [5]               19.4              
Fair value [2],[5]               $ (19.2)              
Investment, Identifier [Axis]: Encora Digital Inc, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Interest rate, paid in kind [12],[15] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 65.1                            
Amortized cost [15] 63.9                            
Fair value [3],[15] $ (61.7)                            
Investment, Identifier [Axis]: Encora Digital Inc, Software & Services 1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15] 2.40% 2.40% 2.40% 2.40% 2.40% 2.40% 2.40%                
Investment, Identifier [Axis]: Encora Digital Inc, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 19.6                            
Amortized cost [4] 19.4                            
Fair value [3],[4] $ (18.6)                            
Investment, Identifier [Axis]: Encora Digital Inc, Software & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 9.80% 9.80% 9.80% 9.80% 9.80% 9.80% 9.80%                
Principal amount [15],[17] $ 23.8                            
Amortized cost [15] 23.2                            
Fair value [3],[15] $ (22.6)                            
Investment, Identifier [Axis]: Encora Digital Inc, Software & Services 3 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 9.80% 9.80% 9.80% 9.80% 9.80% 9.80% 9.80%                
Investment, Identifier [Axis]: Entertainment Benefits Group LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Interest rate, paid in kind               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%  
Principal amount               $ 2.6              
Amortized cost               2.6              
Fair value               $ (2.5)              
Investment, Identifier [Axis]: Entertainment Benefits Group LLC | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind               2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%  
Investment, Identifier [Axis]: Entertainment Benefits Group LLC, Senior Secured Loans—First Lien Media & Entertainment, September 30, 2024 -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Interest rate, paid in kind [32]               2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 0.4              
Amortized cost [32]               0.4              
Fair value [2],[32]               $ (0.4)              
Investment, Identifier [Axis]: Entertainment Benefits Group LLC, Senior Secured Loans—First Lien Media & Entertainment, September 30, 2024 -1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32]               2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%  
Investment, Identifier [Axis]: Entertainment Benefits Group LLC, Senior Secured Loans—First Lien Media & Entertainment, September 30, 2024 -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Interest rate, paid in kind [5]               2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 10.2              
Amortized cost [5]               9.6              
Fair value [2],[5]               $ (9.9)              
Investment, Identifier [Axis]: Entertainment Benefits Group LLC, Senior Secured Loans—First Lien Media & Entertainment, September 30, 2024 -2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [5]               2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%  
Investment, Identifier [Axis]: Entertainment Benefits Group LLC, Senior Secured Loans—First Lien Media & Entertainment, September 30, 2025                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[9],[32],[39],[43]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Interest rate, paid in kind [8],[9],[32],[39],[43]               2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%  
Base rate floor [8],[9],[32],[39],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[8],[9],[32],[39],[43]               $ 64.0              
Amortized cost [8],[9],[32],[39],[43]               59.1              
Fair value [2],[8],[9],[32],[39],[43]               $ (61.7)              
Investment, Identifier [Axis]: Entertainment Benefits Group LLC, Senior Secured Loans—First Lien Media & Entertainment, September 30, 2025 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [8],[9],[32],[39],[43]               2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%  
Investment, Identifier [Axis]: Envigo Laboratories Inc, Series A Warrant, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 10,924 [28],[34] 10,924 [28],[34] 10,924 [28],[34] 10,924 [28],[34] 10,924 [28],[34] 10,924 [28],[34] 10,924 [28],[34] 10,924 [23],[33] 10,924 [23],[33] 10,924 [23],[33] 10,924 [23],[33] 10,924 [23],[33] 10,924 [23],[33] 10,924 [23],[33]  
Amortized cost $ 0.0 [28],[34]             $ 0.0 [23],[33]              
Fair value $ 0.0 [1],[28],[34]             $ 0.0 [2],[23],[33]              
Investment, Identifier [Axis]: Envigo Laboratories Inc, Series B Warrant, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 17,515 [28],[34] 17,515 [28],[34] 17,515 [28],[34] 17,515 [28],[34] 17,515 [28],[34] 17,515 [28],[34] 17,515 [28],[34] 17,515 [23],[33] 17,515 [23],[33] 17,515 [23],[33] 17,515 [23],[33] 17,515 [23],[33] 17,515 [23],[33] 17,515 [23],[33]  
Amortized cost $ 0.0 [28],[34]             $ 0.0 [23],[33]              
Fair value $ 0.0 [1],[28],[34]             $ 0.0 [2],[23],[33]              
Investment, Identifier [Axis]: Envirotainer Ltd | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Interest rate, paid in kind 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | €       € 14.9                      
Amortized cost $ 13.9                            
Fair value $ (15.1)                            
Investment, Identifier [Axis]: Envirotainer Ltd | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00%                
Investment, Identifier [Axis]: Envirotainer Ltd 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Interest rate, paid in kind 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount $ 7.6                            
Amortized cost 7.4                            
Fair value $ (7.3)                            
Investment, Identifier [Axis]: Envirotainer Ltd 1 | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00%                
Investment, Identifier [Axis]: Envirotainer Ltd, Transportation                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12],[29] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Interest rate, paid in kind [4],[12],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor [4],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | € [4],[17],[29]       € 2.7                      
Amortized cost [4],[29] $ 2.7                            
Fair value [3],[4],[29] $ (2.6)                            
Investment, Identifier [Axis]: Envirotainer Ltd, Transportation | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [4],[12],[29] 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00%                
Investment, Identifier [Axis]: Excelitas Technologies Corp | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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               $ 22.6              
Amortized cost               19.7              
Fair value               $ (22.7)              
Investment, Identifier [Axis]: Excelitas Technologies Corp 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount | €       € 4.1                      
Amortized cost $ 4.2                            
Fair value $ (4.2)                            
Investment, Identifier [Axis]: Excelitas Technologies Corp 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 24.5                            
Amortized cost 24.3                            
Fair value $ (23.9)                            
Investment, Identifier [Axis]: Excelitas Technologies Corp, Technology Hardware & Equipment 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 1.3                            
Amortized cost [15] 1.3                            
Fair value [3],[15] $ (1.3)                            
Investment, Identifier [Axis]: Excelitas Technologies Corp, Technology Hardware & Equipment 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 1.0                            
Amortized cost [4] 1.0                            
Fair value [3],[4] $ (1.0)                            
Investment, Identifier [Axis]: Excelitas Technologies Corp, Technology Hardware & Equipment 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 4.7                            
Amortized cost [4] 4.7                            
Fair value [3],[4] (4.6)                            
Investment, Identifier [Axis]: Fairway Group Holdings Corp                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[32],[42]               11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%  
Principal amount [6],[20],[23],[32],[42]               $ 6.9              
Amortized cost [20],[23],[32],[42]               0.0              
Fair value               $ 0.0 [2],[20],[23],[32],[42]             $ 0.0
Investment, Identifier [Axis]: Fairway Group Holdings Corp | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[32],[42]               11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%  
Investment, Identifier [Axis]: Fairway Group Holdings Corp 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value 0.0             $ (0.7)             0.0
Investment, Identifier [Axis]: Fairway Group Holdings Corp 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value 0.0             0.0             0.0
Investment, Identifier [Axis]: Fairway Group Holdings Corp 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value 0.0             0.0              
Investment, Identifier [Axis]: Fairway Group Holdings Corp, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ 0.0             0.0
Investment, Identifier [Axis]: Fairway Group Holdings Corp, Common Stock, Food & Staples Retailing                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [23],[32],[42]               103,091 103,091 103,091 103,091 103,091 103,091 103,091  
Amortized cost [23],[32],[42]               $ 0.0              
Fair value [2],[23],[32],[42]               $ 0.0              
Investment, Identifier [Axis]: Fairway Group Holdings Corp, Senior Secured Loans—First Lien, Food & Staples Retailing, November 27, 2023                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[32],[42]               12.00% 12.00% 12.00% 12.00% 12.00% 12.00% 12.00%  
Principal amount [6],[20],[23],[32],[42]               $ 11.7              
Amortized cost [20],[23],[32],[42]               1.0              
Fair value [2],[20],[23],[32],[42]               $ (0.7)              
Investment, Identifier [Axis]: Fairway Group Holdings Corp, Senior Secured Loans—First Lien, Food & Staples Retailing, November 27, 2023 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[32],[42]               12.00% 12.00% 12.00% 12.00% 12.00% 12.00% 12.00%  
Investment, Identifier [Axis]: Fairway Group Holdings Corp, Senior Secured Loans—First Lien, Food & Staples Retailing, November 28, 2023                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[32],[42]               10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%  
Principal amount [6],[20],[23],[32],[42]               $ 7.6              
Amortized cost [20],[23],[32],[42]               0.0              
Fair value [2],[20],[23],[32],[42]               $ 0.0              
Investment, Identifier [Axis]: Fairway Group Holdings Corp, Senior Secured Loans—First Lien, Food & Staples Retailing, November 28, 2023 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[32],[42]               10.00% 10.00% 10.00% 10.00% 10.00% 10.00% 10.00%  
Investment, Identifier [Axis]: Follett Software Co | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               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%  
Principal amount               $ 37.9              
Amortized cost               37.5              
Fair value               $ (37.7)              
Investment, Identifier [Axis]: Follett Software Co 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 37.5                            
Amortized cost 37.2                            
Fair value $ (36.7)                            
Investment, Identifier [Axis]: Follett Software Co, Senior Secured Loans—First Lien, Software & Services, August 31, 2027t 2027                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 9.9              
Amortized cost [5]               9.9              
Fair value [2],[5]               $ (9.8)              
Investment, Identifier [Axis]: Follett Software Co, Senior Secured Loans—First Lien, Software & Services, August 31, 2028                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[9],[38],[43]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [8],[9],[38],[43]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[8],[9],[38],[43]               $ 74.4              
Amortized cost [8],[9],[38],[43]               73.7              
Fair value [2],[8],[9],[38],[43]               $ (74.1)              
Investment, Identifier [Axis]: Follett Software Co, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[14],[18],[19] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [13],[14],[18],[19] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[14],[17],[18],[19] $ 73.7                            
Amortized cost [13],[14],[18],[19] 73.1                            
Fair value [3],[13],[14],[18],[19] $ (72.1)                            
Investment, Identifier [Axis]: Follett Software Co, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 9.9                            
Amortized cost [4] 9.9                            
Fair value [3],[4] $ (9.7)                            
Investment, Identifier [Axis]: Foundation Consumer Brands LLC, Pharmaceuticals, Biotechnology & Life Sciences 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[40] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [15],[18],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[18],[40] $ 83.9                            
Amortized cost [15],[18],[40] 80.5                            
Fair value [3],[15],[18],[40] $ (84.7)                            
Investment, Identifier [Axis]: Foundation Consumer Brands LLC, Pharmaceuticals, Biotechnology & Life Sciences 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 6.6                            
Amortized cost [4] 6.6                            
Fair value [3],[4] $ (6.6)                            
Investment, Identifier [Axis]: Foundation Consumer Brands LLC, Senior Secured Loans—First Lien, Pharmaceuticals, Biotechnology & Life Sciences, February 12, 2027 -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[39]               6.38% 6.38% 6.38% 6.38% 6.38% 6.38% 6.38%  
Base rate floor [32],[39]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[39]               $ 97.1              
Amortized cost [32],[39]               93.0              
Fair value [2],[32],[39]               $ (98.0)              
Investment, Identifier [Axis]: Foundation Consumer Brands LLC, Senior Secured Loans—First Lien, Pharmaceuticals, Biotechnology & Life Sciences, February 12, 2027 -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.38% 6.38% 6.38% 6.38% 6.38% 6.38% 6.38%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 6.6              
Amortized cost [5]               6.6              
Fair value [2],[5]               $ (6.6)              
Investment, Identifier [Axis]: Foundation Risk Partners Corp, Insurance 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 2.9                            
Amortized cost [15] 2.8                            
Fair value [3],[15] $ (2.8)                            
Investment, Identifier [Axis]: Foundation Risk Partners Corp, Insurance 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [15],[40] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17],[40] $ 79.9                            
Amortized cost [15],[40] 78.8                            
Fair value [3],[15],[40] $ (78.1)                            
Investment, Identifier [Axis]: Foundation Risk Partners Corp, Insurance 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 4.1                            
Amortized cost [4] 4.1                            
Fair value [3],[4] $ (4.0)                            
Investment, Identifier [Axis]: Foundation Risk Partners Corp, Senior Secured Loans—First Lien, Insurance, Maturing October 29, 2027                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 7.0              
Amortized cost [5]               6.9              
Fair value [2],[5]               $ (6.9)              
Investment, Identifier [Axis]: Foundation Risk Partners Corp, Senior Secured Loans—First Lien, Insurance, Maturing October 29, 2028 -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[32]               $ 74.3              
Amortized cost [32]               73.2              
Fair value [2],[32]               $ (73.3)              
Investment, Identifier [Axis]: Foundation Risk Partners Corp, Senior Secured Loans—First Lien, Insurance, Maturing October 29, 2028 -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 6.2              
Amortized cost [5]               6.2              
Fair value [2],[5]               $ (6.1)              
Investment, Identifier [Axis]: Fox Head Inc, Common Stock, Consumer Durables & Apparel                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 10,000,000 [15],[54] 10,000,000 [15],[54] 10,000,000 [15],[54] 10,000,000 [15],[54] 10,000,000 [15],[54] 10,000,000 [15],[54] 10,000,000 [15],[54] 10,000,000 [11],[23],[32] 10,000,000 [11],[23],[32] 10,000,000 [11],[23],[32] 10,000,000 [11],[23],[32] 10,000,000 [11],[23],[32] 10,000,000 [11],[23],[32] 10,000,000 [11],[23],[32]  
Amortized cost $ 2.9 [15],[54]             $ 8.0 [11],[23],[32]              
Fair value 0.0 [1],[15],[54]             $ (10.9) [2],[11],[23],[32]              
Investment, Identifier [Axis]: Frontline Technologies Group LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               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%  
Principal amount               $ 19.7              
Amortized cost               19.8              
Fair value               $ (19.7)              
Investment, Identifier [Axis]: Frontline Technologies Group LLC, Senior Secured Loans—First Lien, Software & Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [10],[32],[39]               5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%  
Base rate floor [10],[32],[39]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[10],[32],[39]               $ 78.7              
Amortized cost [10],[32],[39]               78.1              
Fair value [2],[10],[32],[39]               $ (78.7)              
Investment, Identifier [Axis]: Frontline Technologies Group LLC, Senior Secured Loans—First Lien, Software & Services -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[33]               5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%  
Base rate floor [32],[33]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[33]               $ 75.6              
Amortized cost [32],[33]               71.7              
Fair value [2],[32],[33]               (76.2)              
Investment, Identifier [Axis]: Fronton BV, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (1.0)             $ (1.4)             (1.2)
Investment, Identifier [Axis]: Fronton BV, Common Stock, Consumer Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 14,943 [28],[41],[55] 14,943 [28],[41],[55] 14,943 [28],[41],[55] 14,943 [28],[41],[55] 14,943 [28],[41],[55] 14,943 [28],[41],[55] 14,943 [28],[41],[55] 14,943 [23],[42],[56] 14,943 [23],[42],[56] 14,943 [23],[42],[56] 14,943 [23],[42],[56] 14,943 [23],[42],[56] 14,943 [23],[42],[56] 14,943 [23],[42],[56]  
Amortized cost $ 0.0 [28],[41],[55]             $ 0.0 [23],[42],[56]              
Fair value (1.0) [1],[28],[41],[55]             (1.4) [2],[23],[42],[56]              
Investment, Identifier [Axis]: GA Capital Specialty Lending Fund, Limited Partnership Interest | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount               1.0              
Amortized cost               0.0              
Fair value               $ (4.5)              
Investment, Identifier [Axis]: GA Capital Specialty Lending Fund, Limited Partnership Interest | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount 1.0                            
Amortized cost 0.0                            
Fair value $ (5.3)                            
Investment, Identifier [Axis]: Galaxy Universal LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 36.2              
Amortized cost [32]               35.8              
Fair value [2],[32]               $ (35.8)              
Investment, Identifier [Axis]: Galaxy Universal LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 8.8                            
Amortized cost 8.8                            
Fair value $ (8.7)                            
Investment, Identifier [Axis]: Galaxy Universal LLC, Common Stock, Consumer Durables & Apparel                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 228,806 [28],[51] 228,806 [28],[51] 228,806 [28],[51] 228,806 [28],[51] 228,806 [28],[51] 228,806 [28],[51] 228,806 [28],[51] 228,806 [23],[32] 228,806 [23],[32] 228,806 [23],[32] 228,806 [23],[32] 228,806 [23],[32] 228,806 [23],[32] 228,806 [23],[32]  
Amortized cost $ 35.4 [28],[51]             $ 35.5 [23],[32]              
Fair value $ (7.5) [1],[28],[51]             $ (35.5) [2],[23],[32]              
Investment, Identifier [Axis]: Galaxy Universal LLC, Consumer Durables & Apparel 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 7.5                            
Amortized cost [15] 7.5                            
Fair value [3],[15] $ (7.5)                            
Investment, Identifier [Axis]: Galaxy Universal LLC, Consumer Durables & Apparel 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 88.0                            
Amortized cost [15] 88.0                            
Fair value [3],[15] $ (85.3)                            
Investment, Identifier [Axis]: Galaxy Universal LLC, Consumer Durables & Apparel 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 21.5                            
Amortized cost [15] 21.4                            
Fair value [3],[15] $ (21.2)                            
Investment, Identifier [Axis]: Galaxy Universal LLC, Senior Secured Loans—First Lien, Consumer Durables & Apparel, Maturing February 4,2022 -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount | € [6],[32]                     € 88.9        
Amortized cost [32]               $ 88.9              
Fair value [2],[32]               (88.9)              
Investment, Identifier [Axis]: Galaxy Universal LLC, Senior Secured Loans—First Lien, Consumer Durables & Apparel, Maturing February 4,2022 -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [5],[6]               7.7              
Amortized cost [5]               7.7              
Fair value [2],[5]               (7.7)              
Investment, Identifier [Axis]: Galaxy Universal LLC, Senior Secured Loans—First Lien, Consumer Durables & Apparel, November 1, 2026                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [6],[32]               0.9              
Amortized cost [32]               0.9              
Fair value [2],[32]               $ (0.9)              
Investment, Identifier [Axis]: Galaxy Universal LLC, Trade Claim, Consumer Durables & Apparel                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 7,701,195 [15],[28] 7,701,195 [15],[28] 7,701,195 [15],[28] 7,701,195 [15],[28] 7,701,195 [15],[28] 7,701,195 [15],[28] 7,701,195 [15],[28] 27,256,114 [23],[32] 27,256,114 [23],[32] 27,256,114 [23],[32] 27,256,114 [23],[32] 27,256,114 [23],[32] 27,256,114 [23],[32] 27,256,114 [23],[32]  
Amortized cost $ 4.6 [15],[28]             $ 16.4 [23],[32]              
Fair value $ (1.7) [1],[15],[28]             $ (16.4) [2],[23],[32]              
Investment, Identifier [Axis]: Galway Partners Holdings LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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%  
Interest rate, paid in kind 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%  
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 $ 36.9             $ 20.3              
Amortized cost 36.2             20.0              
Fair value $ (36.4)             $ (20.0)              
Investment, Identifier [Axis]: Galway Partners Holdings LLC | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 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%  
Investment, Identifier [Axis]: Galway Partners Holdings LLC, Insurance 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[14],[15],[19],[40] 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%                
Interest rate, paid in kind [12],[13],[14],[15],[19],[40] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor [13],[14],[15],[19],[40] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[14],[15],[17],[19],[40] $ 111.1                            
Amortized cost [13],[14],[15],[19],[40] 109.4                            
Fair value [3],[13],[14],[15],[19],[40] $ (109.7)                            
Investment, Identifier [Axis]: Galway Partners Holdings LLC, Insurance 1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[13],[14],[15],[19],[40] 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30%                
Investment, Identifier [Axis]: Galway Partners Holdings LLC, Insurance 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%                
Interest rate, paid in kind [4],[12] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 12.0                            
Amortized cost [4] 11.8                            
Fair value [3],[4] $ (11.8)                            
Investment, Identifier [Axis]: Galway Partners Holdings LLC, Insurance 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [4],[12] 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30%                
Investment, Identifier [Axis]: Galway Partners Holdings LLC, Insurance 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%                
Interest rate, paid in kind [4],[12] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 1.3                            
Amortized cost [4] 1.3                            
Fair value [3],[4] $ (1.3)                            
Investment, Identifier [Axis]: Galway Partners Holdings LLC, Insurance 3 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [4],[12] 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30%                
Investment, Identifier [Axis]: Galway Partners Holdings LLC, Senior Secured Loans—First Lien, Insurance, Maturing September 29, 2028 -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[9],[32],[38]               5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%  
Interest rate, paid in kind [8],[9],[32],[38]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base rate floor [8],[9],[32],[38]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[8],[9],[32],[38]               $ 128.1              
Amortized cost [8],[9],[32],[38]               125.5              
Fair value [2],[8],[9],[32],[38]               $ (126.0)              
Investment, Identifier [Axis]: Galway Partners Holdings LLC, Senior Secured Loans—First Lien, Insurance, Maturing September 29, 2028 -1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [8],[9],[32],[38]               1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30%  
Investment, Identifier [Axis]: Galway Partners Holdings LLC, Senior Secured Loans—First Lien, Insurance, Maturing September 29, 2028 -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [5]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 22.4              
Amortized cost [5]               22.4              
Fair value [2],[5]               $ (22.0)              
Investment, Identifier [Axis]: Galway Partners Holdings LLC, Senior Secured Loans—First Lien, Insurance, Maturing September 29, 2028 -2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [5]               1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30%  
Investment, Identifier [Axis]: Galway Partners Holdings LLC, Senior Secured Loans—First Lien, Insurance, Maturing September 30, 2027                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%  
Interest rate, paid in kind [5]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 12.0              
Amortized cost [5]               11.7              
Fair value [2],[5]               $ (11.8)              
Investment, Identifier [Axis]: Galway Partners Holdings LLC, Senior Secured Loans—First Lien, Insurance, Maturing September 30, 2027 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [5]               1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30%  
Investment, Identifier [Axis]: General Datatech LP                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[9],[32],[38],[39],[43]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [8],[9],[32],[38],[39],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[8],[9],[32],[38],[39],[43]               $ 169.1              
Amortized cost [8],[9],[32],[38],[39],[43]               167.5              
Fair value [2],[8],[9],[32],[38],[39],[43]               $ (166.5)              
Investment, Identifier [Axis]: General Datatech LP | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 18.3                            
Amortized cost 17.7                            
Fair value $ (17.1)                            
Investment, Identifier [Axis]: General Datatech LP 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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               $ 10.2              
Amortized cost               10.0              
Fair value               $ (10.0)              
Investment, Identifier [Axis]: General Datatech LP, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[14],[15],[18],[19],[40] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [13],[14],[15],[18],[19],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[14],[15],[17],[18],[19],[40] $ 156.4                            
Amortized cost [13],[14],[15],[18],[19],[40] 155.1                            
Fair value [3],[13],[14],[15],[18],[19],[40] $ (146.5)                            
Investment, Identifier [Axis]: Genesys Telecommunications Laboratories Inc, Class A Shares, Technology Hardware & Equipment                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 40,529 [15],[28] 40,529 [15],[28] 40,529 [15],[28] 40,529 [15],[28] 40,529 [15],[28] 40,529 [15],[28] 40,529 [15],[28] 40,529 [23],[32] 40,529 [23],[32] 40,529 [23],[32] 40,529 [23],[32] 40,529 [23],[32] 40,529 [23],[32] 40,529 [23],[32]  
Amortized cost $ 0.0 [15],[28]             $ 0.0 [23],[32]              
Fair value $ 0.0 [1],[15],[28]             $ 0.0 [2],[23],[32]              
Investment, Identifier [Axis]: Genesys Telecommunications Laboratories Inc, Ordinary Shares, Technology Hardware & Equipment                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 41,339 [15],[28] 41,339 [15],[28] 41,339 [15],[28] 41,339 [15],[28] 41,339 [15],[28] 41,339 [15],[28] 41,339 [15],[28] 41,339 [23],[32] 41,339 [23],[32] 41,339 [23],[32] 41,339 [23],[32] 41,339 [23],[32] 41,339 [23],[32] 41,339 [23],[32]  
Amortized cost $ 0.0 [15],[28]             $ 0.0 [23],[32]              
Fair value $ 0.0 [1],[15],[28]             $ 0.0 [2],[23],[32]              
Investment, Identifier [Axis]: Genesys Telecommunications Laboratories Inc, Preferred Stock, Technology Hardware & Equipment                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 1,050,465 [15],[28] 1,050,465 [15],[28] 1,050,465 [15],[28] 1,050,465 [15],[28] 1,050,465 [15],[28] 1,050,465 [15],[28] 1,050,465 [15],[28] 1,050,465 [23],[32] 1,050,465 [23],[32] 1,050,465 [23],[32] 1,050,465 [23],[32] 1,050,465 [23],[32] 1,050,465 [23],[32] 1,050,465 [23],[32]  
Amortized cost $ 0.0 [15],[28]             $ 0.0 [23],[32]              
Fair value $ 0.0 [1],[15],[28]             $ 0.0 [2],[23],[32]              
Investment, Identifier [Axis]: Gigamon Inc, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 170.4                            
Amortized cost [15] 168.9                            
Fair value [3],[15] $ (163.2)                            
Investment, Identifier [Axis]: Gigamon Inc, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 9.3                            
Amortized cost [4] 9.3                            
Fair value [3],[4] $ (8.9)                            
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 [15],[28],[53],[54] 149,494,590 [15],[28],[53],[54] 149,494,590 [15],[28],[53],[54] 149,494,590 [15],[28],[53],[54] 149,494,590 [15],[28],[53],[54] 149,494,590 [15],[28],[53],[54] 149,494,590 [15],[28],[53],[54] 149,494,590 [6],[24],[32] 149,494,590 [6],[24],[32] 149,494,590 [6],[24],[32] 149,494,590 [6],[24],[32] 149,494,590 [6],[24],[32] 149,494,590 [6],[24],[32] 149,494,590 [6],[24],[32]  
Amortized cost $ 69.4 [15],[28],[53],[54]             $ 69.4 [24],[32]              
Fair value $ 0.0 [3],[15],[28],[53],[54]             $ 0.0 [2],[24],[32]              
Investment, Identifier [Axis]: Global Jet Capital LLC, Preferred Stock, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 9.00% [12],[15],[25],[28],[53],[54] 9.00% [12],[15],[25],[28],[53],[54] 9.00% [12],[15],[25],[28],[53],[54] 9.00% [12],[15],[25],[28],[53],[54] 9.00% [12],[15],[25],[28],[53],[54] 9.00% [12],[15],[25],[28],[53],[54] 9.00% [12],[15],[25],[28],[53],[54] 9.00% [7],[11],[32],[52] 9.00% [7],[11],[32],[52] 9.00% [7],[11],[32],[52] 9.00% [7],[11],[32],[52] 9.00% [7],[11],[32],[52] 9.00% [7],[11],[32],[52] 9.00% [7],[11],[32],[52]  
Principal amount $ 453.1 [15],[17],[25],[28],[53],[54]             $ 414.0 [6],[11],[32],[52]              
Amortized cost 309.4 [15],[25],[28],[53],[54]             304.8 [11],[32],[52]              
Fair value $ (232.2) [3],[15],[25],[28],[53],[54]             $ (302.2) [2],[11],[32],[52]              
Investment, Identifier [Axis]: Global Jet Capital LLC, Preferred Stock, Commercial & Professional Services 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 9.00% [12],[15],[25],[28],[53],[54] 9.00% [12],[15],[25],[28],[53],[54] 9.00% [12],[15],[25],[28],[53],[54] 9.00% [12],[15],[25],[28],[53],[54] 9.00% [12],[15],[25],[28],[53],[54] 9.00% [12],[15],[25],[28],[53],[54] 9.00% [12],[15],[25],[28],[53],[54] 9.00% [7],[11],[32],[52] 9.00% [7],[11],[32],[52] 9.00% [7],[11],[32],[52] 9.00% [7],[11],[32],[52] 9.00% [7],[11],[32],[52] 9.00% [7],[11],[32],[52] 9.00% [7],[11],[32],[52]  
Investment, Identifier [Axis]: Global Jet Capital LLC, Structured Mezzanine, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52]  
Principal amount $ 28.0 [15],[17],[29],[53],[54]             $ 53.6 [6],[11],[24],[32],[52]              
Amortized cost 21.2 [15],[29],[53],[54]             36.9 [11],[24],[32],[52]              
Fair value $ (28.0) [3],[15],[29],[53],[54]             $ (53.6) [2],[11],[24],[32],[52]              
Investment, Identifier [Axis]: Global Jet Capital LLC, Structured Mezzanine, Commercial & Professional Services 1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52]  
Investment, Identifier [Axis]: Global Jet Capital LLC, Structured Mezzanine, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52]  
Principal amount $ 20.5 [15],[17],[29],[53],[54]             $ 39.2 [6],[11],[24],[32],[52]              
Amortized cost 15.1 [15],[29],[53],[54]             26.9 [11],[24],[32],[52]              
Fair value $ (20.5) [3],[15],[29],[53],[54]             $ (39.2) [2],[11],[24],[32],[52]              
Investment, Identifier [Axis]: Global Jet Capital LLC, Structured Mezzanine, Commercial & Professional Services 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52]  
Investment, Identifier [Axis]: Global Jet Capital LLC, Structured Mezzanine, Commercial & Professional Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52]  
Principal amount $ 2.4 [15],[17],[29],[53],[54]             $ 4.6 [6],[11],[24],[32],[52]              
Amortized cost 1.7 [15],[29],[53],[54]             3.1 [11],[24],[32],[52]              
Fair value $ (2.4) [3],[15],[29],[53],[54]             $ (4.6) [2],[11],[24],[32],[52]              
Investment, Identifier [Axis]: Global Jet Capital LLC, Structured Mezzanine, Commercial & Professional Services 3 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [12],[15],[29],[53],[54] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52] 15.00% [7],[11],[24],[32],[52]  
Investment, Identifier [Axis]: Global Lending Services LLC, Private Equity | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares               3,653,142 3,653,142 3,653,142 3,653,142 3,653,142 3,653,142 3,653,142  
Amortized cost               $ 3.7              
Fair value               $ (4.6)              
Investment, Identifier [Axis]: Global Lending Services LLC, Private Equity 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 $ 2.2                            
Fair value $ (2.4)                            
Investment, Identifier [Axis]: Global Lending Services LLC, Private Equity 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 $ 22.9                            
Fair value $ (18.3)                            
Investment, Identifier [Axis]: Global Lending Services LLC, Private Equity, Diversified Financials 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 7,391,109 [15],[29] 7,391,109 [15],[29] 7,391,109 [15],[29] 7,391,109 [15],[29] 7,391,109 [15],[29] 7,391,109 [15],[29] 7,391,109 [15],[29] 12,222,437 [6],[24],[32] 12,222,437 [6],[24],[32] 12,222,437 [6],[24],[32] 12,222,437 [6],[24],[32] 12,222,437 [6],[24],[32] 12,222,437 [6],[24],[32] 12,222,437 [6],[24],[32]  
Amortized cost $ 8.6 [15],[29]             $ 14.2 [24],[32]              
Fair value $ (8.2) [3],[15],[29]             $ (15.5) [2],[24],[32]              
Investment, Identifier [Axis]: Global Lending Services LLC, Private Equity, Diversified Financials 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 10,356,657 [15],[29] 10,356,657 [15],[29] 10,356,657 [15],[29] 10,356,657 [15],[29] 10,356,657 [15],[29] 10,356,657 [15],[29] 10,356,657 [15],[29] 22,352,639 [6],[24],[32] 22,352,639 [6],[24],[32] 22,352,639 [6],[24],[32] 22,352,639 [6],[24],[32] 22,352,639 [6],[24],[32] 22,352,639 [6],[24],[32] 22,352,639 [6],[24],[32]  
Amortized cost $ 10.4 [15],[29]             $ 24.2 [24],[32]              
Fair value $ (10.9) [3],[15],[29]             $ (28.5) [2],[24],[32]              
Investment, Identifier [Axis]: Global Lending Services LLC, Private Equity, Diversified Financials 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [15],[28],[29] 9,963,808 9,963,808 9,963,808 9,963,808 9,963,808 9,963,808 9,963,808                
Amortized cost [15],[28],[29] $ 10.0                            
Fair value [3],[15],[28],[29] $ (10.0)                            
Investment, Identifier [Axis]: Gracent LLC, Health Care Equipment & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 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%                
Principal amount [15],[17] $ 25.9                            
Amortized cost [15] 26.6                            
Fair value [3],[15] $ (22.1)                            
Investment, Identifier [Axis]: Gracent LLC, Health Care Equipment & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15] 12.00% 12.00% 12.00% 12.00% 12.00% 12.00% 12.00%                
Principal amount [15],[17],[25],[28] $ 22.9                            
Amortized cost [15],[25],[28] 22.6                            
Fair value [3],[15],[25],[28] $ (11.4)                            
Investment, Identifier [Axis]: Gracent LLC, Health Care Equipment & Services 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15] 12.00% 12.00% 12.00% 12.00% 12.00% 12.00% 12.00%                
Investment, Identifier [Axis]: Gracent LLC, NP-1 Common Stock, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [28],[51] 1,000,000 1,000,000 1,000,000 1,000,000 1,000,000 1,000,000 1,000,000                
Amortized cost [28],[51] $ 4.2                            
Fair value [1],[28],[51] $ 0.0                            
Investment, Identifier [Axis]: Greystone Equity Member Corp                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [24],[32]               7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25%  
Base rate floor [24],[32]               3.80% 3.80% 3.80% 3.80% 3.80% 3.80% 3.80%  
Principal amount [6],[24],[32]               $ 194.8              
Amortized cost [24],[32]               182.7              
Fair value [2],[24],[32]               $ (192.6)              
Investment, Identifier [Axis]: Greystone Equity Member Corp 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 3.80% 3.80% 3.80% 3.80% 3.80% 3.80% 3.80% 3.80% 3.80% 3.80% 3.80% 3.80% 3.80% 3.80%  
Principal amount $ 30.2             $ 30.2              
Amortized cost 30.1             30.0              
Fair value $ (29.3)             (29.9)              
Investment, Identifier [Axis]: Greystone Equity Member Corp, Diversified Financials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[29] 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25%                
Base rate floor [15],[29] 3.80% 3.80% 3.80% 3.80% 3.80% 3.80% 3.80%                
Principal amount [15],[17],[29] $ 194.8                            
Amortized cost [15],[29] 185.0                            
Fair value [3],[15],[29] $ (188.7)                            
Investment, Identifier [Axis]: HKA, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[29] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Interest rate, paid in kind [12],[15],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor [15],[29] 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount [15],[17],[29] $ 4.4                            
Amortized cost [15],[29] 4.3                            
Fair value [3],[15],[29] $ (4.2)                            
Investment, Identifier [Axis]: HKA, Commercial & Professional Services 1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15],[29] 1.80% 1.80% 1.80% 1.80% 1.80% 1.80% 1.80%                
Investment, Identifier [Axis]: HKA, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12],[29] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Interest rate, paid in kind [4],[12],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor [4],[29] 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount [4],[17],[29] $ 0.2                            
Amortized cost [4],[29] 0.2                            
Fair value [3],[4],[29] $ (0.2)                            
Investment, Identifier [Axis]: HKA, Commercial & Professional Services 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [4],[12],[29] 1.80% 1.80% 1.80% 1.80% 1.80% 1.80% 1.80%                
Investment, Identifier [Axis]: HM Dunn Co Inc 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (35.6)             (33.6) [57]             0.0 [57]
Investment, Identifier [Axis]: HM Dunn Co Inc 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             (2.0) [57]             0.0 [57]
Investment, Identifier [Axis]: HM Dunn Co Inc 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value [58]               0.0             (0.3)
Investment, Identifier [Axis]: HM Dunn Co Inc 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value [58]               0.0             (0.2)
Investment, Identifier [Axis]: HM Dunn Co Inc, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Interest rate, paid in kind [12],[15],[30] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor [15],[30] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[30] $ 35.6                            
Amortized cost [15],[30] 35.6                            
Fair value [3],[15],[30] $ (35.6)                            
Investment, Identifier [Axis]: HM Dunn Co Inc, Capital Goods 1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15],[30] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Investment, Identifier [Axis]: HM Dunn Co Inc, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Interest rate, paid in kind [4],[12],[30] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor [4],[30] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17],[30] $ 2.0                            
Amortized cost [4],[30] 2.0                            
Fair value [3],[4],[30] $ (2.0)                            
Investment, Identifier [Axis]: HM Dunn Co Inc, Capital Goods 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [4],[12],[30] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Investment, Identifier [Axis]: HM Dunn Co Inc, Preferred Stock, Series A                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (16.9)             (7.1) [57]             0.0 [57]
Investment, Identifier [Axis]: HM Dunn Co Inc, Preferred Stock, Series A 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value [58]               $ 0.0             0.0
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 [15],[28],[30],[34] 85,385 [15],[28],[30],[34] 85,385 [15],[28],[30],[34] 85,385 [15],[28],[30],[34] 85,385 [15],[28],[30],[34] 85,385 [15],[28],[30],[34] 85,385 [15],[28],[30],[34] 85,385 [23],[31],[32],[33] 85,385 [23],[31],[32],[33] 85,385 [23],[31],[32],[33] 85,385 [23],[31],[32],[33] 85,385 [23],[31],[32],[33] 85,385 [23],[31],[32],[33] 85,385 [23],[31],[32],[33]  
Amortized cost $ 7.1 [15],[28],[30],[34]             $ 7.1 [23],[31],[32],[33]              
Fair value (16.9) [1],[15],[28],[30],[34]             (7.1) [2],[23],[31],[32],[33]              
Investment, Identifier [Axis]: HM Dunn Co Inc, Preferred Stock, Series B                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ 0.0 [57],[58]             0.0 [57],[58]
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 [15],[28],[30],[34] 15,000 [15],[28],[30],[34] 15,000 [15],[28],[30],[34] 15,000 [15],[28],[30],[34] 15,000 [15],[28],[30],[34] 15,000 [15],[28],[30],[34] 15,000 [15],[28],[30],[34] 15,000 [23],[31],[32],[33] 15,000 [23],[31],[32],[33] 15,000 [23],[31],[32],[33] 15,000 [23],[31],[32],[33] 15,000 [23],[31],[32],[33] 15,000 [23],[31],[32],[33] 15,000 [23],[31],[32],[33]  
Amortized cost $ 0.0 [15],[28],[30],[34]             $ 0.0 [23],[31],[32],[33]              
Fair value $ 0.0 [1],[15],[28],[30],[34]             $ 0.0 [2],[23],[31],[32],[33]              
Investment, Identifier [Axis]: HM Dunn Co Inc, Senior Secured Loans—First Lien, Capital Goods -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [31],[32]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [31],[32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[31],[32]               $ 33.6              
Amortized cost [31],[32]               33.6              
Fair value [2],[31],[32]               $ (33.6)              
Investment, Identifier [Axis]: HM Dunn Co Inc, Senior Secured Loans—First Lien, Capital Goods -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [31],[32]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [31],[32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[31],[32]               $ 2.0              
Amortized cost [31],[32]               2.0              
Fair value [2],[31],[32]               $ (2.0)              
Investment, Identifier [Axis]: Harvey Industries Inc, Common Stock, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 5,000,000 [15],[28] 5,000,000 [15],[28] 5,000,000 [15],[28] 5,000,000 [15],[28] 5,000,000 [15],[28] 5,000,000 [15],[28] 5,000,000 [15],[28] 5,000,000 [32] 5,000,000 [32] 5,000,000 [32] 5,000,000 [32] 5,000,000 [32] 5,000,000 [32] 5,000,000 [32]  
Amortized cost $ 2.2 [15],[28]             $ 2.2 [32]              
Fair value $ (5.2) [1],[15],[28]             $ (3.3) [2],[32]              
Investment, Identifier [Axis]: HealthChannels LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 15.4             $ 15.6              
Amortized cost 15.3             15.5              
Fair value $ (10.9)             $ (14.3)              
Investment, Identifier [Axis]: Heniff Transportation Systems LLC, Senior Secured Loans—First Lien, Transportation, Maturing December 3 2024 -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 5.9              
Amortized cost [32]               5.6              
Fair value [2],[32]               $ (5.6)              
Investment, Identifier [Axis]: Heniff Transportation Systems LLC, Senior Secured Loans—First Lien, Transportation, Maturing December 3 2024 -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 11.9              
Amortized cost [5]               11.9              
Fair value [2],[5]               $ (11.1)              
Investment, Identifier [Axis]: Heniff Transportation Systems LLC, Senior Secured Loans—First Lien, Transportation, Maturing December 3 2026 -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[9],[10],[32],[39],[43]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [8],[9],[10],[32],[39],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[8],[9],[10],[32],[39],[43]               $ 137.7              
Amortized cost [8],[9],[10],[32],[39],[43]               130.5              
Fair value [2],[8],[9],[10],[32],[39],[43]               $ (128.7)              
Investment, Identifier [Axis]: Heniff Transportation Systems LLC, Senior Secured Loans—First Lien, Transportation, Maturing December 3 2026 -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 19.4              
Amortized cost [32]               18.6              
Fair value [2],[32]               $ (18.5)              
Investment, Identifier [Axis]: Heniff Transportation Systems LLC, Transportation 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[14],[15],[16],[18],[40] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [13],[14],[15],[16],[18],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[14],[15],[16],[17],[18],[40] $ 135.7                            
Amortized cost [13],[14],[15],[16],[18],[40] 129.8                            
Fair value [3],[13],[14],[15],[16],[18],[40] $ (131.3)                            
Investment, Identifier [Axis]: Heniff Transportation Systems LLC, Transportation 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 19.1                            
Amortized cost [15] 18.4                            
Fair value [3],[15] $ (18.5)                            
Investment, Identifier [Axis]: Heniff Transportation Systems LLC, Transportation 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 17.8                            
Amortized cost [4] 17.6                            
Fair value [3],[4] $ (17.2)                            
Investment, Identifier [Axis]: Hermes UK Ltd | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 19.5             $ 19.5              
Fair value $ (16.1)             $ (19.3)              
Investment, Identifier [Axis]: Hibu Inc, Commercial & Professional Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[14],[15],[18],[19],[40] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [13],[14],[15],[18],[19],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[14],[15],[17],[18],[19],[40] $ 99.0                            
Amortized cost [13],[14],[15],[18],[19],[40] 94.8                            
Fair value [3],[13],[14],[15],[18],[19],[40] $ (99.8)                            
Investment, Identifier [Axis]: Higginbotham Insurance Agency Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 37.6             $ 38.0              
Amortized cost 38.0             38.4              
Fair value $ (37.7)             $ (38.8)              
Investment, Identifier [Axis]: Higginbotham Insurance Agency Inc, Insurance -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[32]               $ 25.3              
Amortized cost [32]               24.6              
Fair value [2],[32]               $ (25.8)              
Investment, Identifier [Axis]: Higginbotham Insurance Agency Inc, Insurance -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%  
Base rate floor [32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[32]               $ 4.5              
Amortized cost [32]               4.3              
Fair value [2],[32]               $ (4.6)              
Investment, Identifier [Axis]: Higginbotham Insurance Agency Inc, Insurance -3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 32.6              
Amortized cost [5]               32.6              
Fair value [2],[5]               (33.3)              
Investment, Identifier [Axis]: Higginbotham Insurance Agency Inc, Insurance 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 4.4                            
Amortized cost [15] 4.4                            
Fair value [3],[15] $ (4.4)                            
Investment, Identifier [Axis]: Higginbotham Insurance Agency Inc, Insurance 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 7.0                            
Amortized cost [15] 6.6                            
Fair value [3],[15] $ (7.0)                            
Investment, Identifier [Axis]: Higginbotham Insurance Agency Inc, Insurance 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 6.0                            
Amortized cost [4] 6.0                            
Fair value [3],[4] (6.0)                            
Investment, Identifier [Axis]: Hilding Anders 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value 0.0             (46.6)             (32.4)
Investment, Identifier [Axis]: Hilding Anders 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value 0.0             0.0             0.0
Investment, Identifier [Axis]: Hilding Anders 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value 0.0             0.0             (30.3)
Investment, Identifier [Axis]: Hilding Anders, Class A Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ 0.0             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 [15],[28],[29],[30] 4,503,411 [15],[28],[29],[30] 4,503,411 [15],[28],[29],[30] 4,503,411 [15],[28],[29],[30] 4,503,411 [15],[28],[29],[30] 4,503,411 [15],[28],[29],[30] 4,503,411 [15],[28],[29],[30] 4,503,411 [23],[24],[31],[32] 4,503,411 [23],[24],[31],[32] 4,503,411 [23],[24],[31],[32] 4,503,411 [23],[24],[31],[32] 4,503,411 [23],[24],[31],[32] 4,503,411 [23],[24],[31],[32] 4,503,411 [23],[24],[31],[32]  
Amortized cost $ 0.1 [15],[28],[29],[30]             $ 0.1 [23],[24],[31],[32]              
Fair value 0.0 [1],[15],[28],[29],[30]             0.0 [2],[23],[24],[31],[32]              
Investment, Identifier [Axis]: Hilding Anders, Class B Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ 0.0             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 [15],[28],[29],[30] 574,791 [15],[28],[29],[30] 574,791 [15],[28],[29],[30] 574,791 [15],[28],[29],[30] 574,791 [15],[28],[29],[30] 574,791 [15],[28],[29],[30] 574,791 [15],[28],[29],[30] 574,791 [23],[24],[31],[32] 574,791 [23],[24],[31],[32] 574,791 [23],[24],[31],[32] 574,791 [23],[24],[31],[32] 574,791 [23],[24],[31],[32] 574,791 [23],[24],[31],[32] 574,791 [23],[24],[31],[32]  
Amortized cost $ 0.0 [15],[28],[29],[30]             $ 0.0 [23],[24],[31],[32]              
Fair value 0.0 [1],[15],[28],[29],[30]             0.0 [2],[23],[24],[31],[32]              
Investment, Identifier [Axis]: Hilding Anders, Class C Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ 0.0             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 [15],[28],[29],[30] 213,201 [15],[28],[29],[30] 213,201 [15],[28],[29],[30] 213,201 [15],[28],[29],[30] 213,201 [15],[28],[29],[30] 213,201 [15],[28],[29],[30] 213,201 [15],[28],[29],[30] 213,201 [23],[24],[31],[32] 213,201 [23],[24],[31],[32] 213,201 [23],[24],[31],[32] 213,201 [23],[24],[31],[32] 213,201 [23],[24],[31],[32] 213,201 [23],[24],[31],[32] 213,201 [23],[24],[31],[32]  
Amortized cost $ 0.0 [15],[28],[29],[30]             $ 0.0 [23],[24],[31],[32]              
Fair value 0.0 [1],[15],[28],[29],[30]             0.0 [2],[23],[24],[31],[32]              
Investment, Identifier [Axis]: Hilding Anders, Consumer Durables & Apparel 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount | € [15],[17],[28],[29],[30]       € 135.2                      
Amortized cost [15],[28],[29],[30] 26.9                            
Fair value [3],[15],[28],[29],[30] $ 0.0                            
Investment, Identifier [Axis]: Hilding Anders, Consumer Durables & Apparel 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 13.00% 13.00% 13.00% 13.00% 13.00% 13.00% 13.00%                
Principal amount | € [15],[17],[25],[28],[29],[30]       € 152.6                      
Amortized cost [15],[25],[28],[29],[30] $ 99.4                            
Fair value [3],[15],[25],[28],[29],[30] $ 0.0                            
Investment, Identifier [Axis]: Hilding Anders, Consumer Durables & Apparel 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 13.00% 13.00% 13.00% 13.00% 13.00% 13.00% 13.00%                
Investment, Identifier [Axis]: Hilding Anders, Equity Options                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ 0.0             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 [15],[28],[29],[30] 236,160,807 [15],[28],[29],[30] 236,160,807 [15],[28],[29],[30] 236,160,807 [15],[28],[29],[30] 236,160,807 [15],[28],[29],[30] 236,160,807 [15],[28],[29],[30] 236,160,807 [15],[28],[29],[30] 236,160,807 [23],[24],[31],[32] 236,160,807 [23],[24],[31],[32] 236,160,807 [23],[24],[31],[32] 236,160,807 [23],[24],[31],[32] 236,160,807 [23],[24],[31],[32] 236,160,807 [23],[24],[31],[32] 236,160,807 [23],[24],[31],[32]  
Amortized cost $ 15.0 [15],[28],[29],[30]             $ 15.0 [23],[24],[31],[32]              
Fair value 0.0 [1],[15],[28],[29],[30]             $ 0.0 [2],[23],[24],[31],[32]              
Investment, Identifier [Axis]: Hilding Anders, Subordinated Debt, Consumer Durables & Apparel - 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[24],[31],[32]               13.00% 13.00% 13.00% 13.00% 13.00% 13.00% 13.00%  
Principal amount [6],[20],[23],[24],[31],[32]               $ 134.4              
Amortized cost [20],[23],[24],[31],[32]               99.4              
Fair value [2],[20],[23],[24],[31],[32]               $ (46.6)              
Investment, Identifier [Axis]: Hilding Anders, Subordinated Debt, Consumer Durables & Apparel - 3 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[24],[31],[32]               13.00% 13.00% 13.00% 13.00% 13.00% 13.00% 13.00%  
Investment, Identifier [Axis]: Hilding Anders, Subordinated Debt, Consumer Durables & Apparel -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount | € [6],[23],[24],[31],[32]                     € 24.8        
Amortized cost [23],[24],[31],[32]               $ 26.9              
Fair value [2],[23],[24],[31],[32]               0.0              
Investment, Identifier [Axis]: Hilding Anders, Subordinated Debt, Consumer Durables & Apparel -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [6],[23],[24],[31],[32]               110.5              
Amortized cost [23],[24],[31],[32]               0.0              
Fair value [2],[23],[24],[31],[32]               0.0              
Investment, Identifier [Axis]: Home Partners JV 2, Private Equity 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value (0.2)             (0.1)             0.0
Investment, Identifier [Axis]: Home Partners JV 2, Private Equity 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (5.0)             $ (1.6)             0.0
Investment, Identifier [Axis]: Home Partners JV 2, Private Equity, Real Estate 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 4,471,509 [15],[28],[29],[41] 4,471,509 [15],[28],[29],[41] 4,471,509 [15],[28],[29],[41] 4,471,509 [15],[28],[29],[41] 4,471,509 [15],[28],[29],[41] 4,471,509 [15],[28],[29],[41] 4,471,509 [15],[28],[29],[41] 1,585,353 [6],[23],[24],[32],[42] 1,585,353 [6],[23],[24],[32],[42] 1,585,353 [6],[23],[24],[32],[42] 1,585,353 [6],[23],[24],[32],[42] 1,585,353 [6],[23],[24],[32],[42] 1,585,353 [6],[23],[24],[32],[42] 1,585,353 [6],[23],[24],[32],[42]  
Amortized cost $ 4.4 [15],[28],[29],[41]             $ 1.5 [23],[24],[32],[42]              
Fair value $ (5.0) [3],[15],[28],[29],[41]             $ (1.6) [2],[23],[24],[32],[42]              
Investment, Identifier [Axis]: Home Partners JV 2, Private Equity, Real Estate 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 168,710 [15],[28],[29],[41] 168,710 [15],[28],[29],[41] 168,710 [15],[28],[29],[41] 168,710 [15],[28],[29],[41] 168,710 [15],[28],[29],[41] 168,710 [15],[28],[29],[41] 168,710 [15],[28],[29],[41] 59,815 [6],[23],[24],[32],[42] 59,815 [6],[23],[24],[32],[42] 59,815 [6],[23],[24],[32],[42] 59,815 [6],[23],[24],[32],[42] 59,815 [6],[23],[24],[32],[42] 59,815 [6],[23],[24],[32],[42] 59,815 [6],[23],[24],[32],[42]  
Amortized cost $ 0.2 [15],[28],[29],[41]             $ 0.1 [23],[24],[32],[42]              
Fair value (0.2) [3],[15],[28],[29],[41]             (0.1) [2],[23],[24],[32],[42]              
Investment, Identifier [Axis]: Home Partners JV 2, Structured Mezzanine                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (10.2)             $ (3.5)             0.0
Investment, Identifier [Axis]: Home Partners JV 2, Structured Mezzanine, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15],[29],[41] 11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%                
Principal amount [15],[17],[29],[41] $ 10.2                            
Amortized cost [15],[29],[41] 10.2                            
Fair value [3],[15],[29],[41] $ (10.2)                            
Investment, Identifier [Axis]: Home Partners JV 2, Structured Mezzanine, Real Estate | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15],[29],[41] 11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%                
Investment, Identifier [Axis]: Home Partners JV 2, Structured Mezzanine, Real Estate 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [7],[24],[32],[42]               11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%  
Principal amount [6],[24],[32],[42]               $ 3.5              
Amortized cost [24],[32],[42]               3.4              
Fair value [2],[24],[32],[42]               $ (3.5)              
Investment, Identifier [Axis]: Home Partners JV 2, Structured Mezzanine, Real Estate 1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [7],[24],[32],[42]               11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%  
Investment, Identifier [Axis]: Home Partners JV 2, Structured Mezzanine, Real Estate 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [5],[7],[24],[42]               11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%  
Principal amount [5],[6],[24],[42]               $ 13.6              
Amortized cost [5],[24],[42]               13.6              
Fair value [2],[5],[24],[42]               $ (13.6)              
Investment, Identifier [Axis]: Home Partners JV 2, Structured Mezzanine, Real Estate 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [5],[7],[24],[42]               11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%  
Investment, Identifier [Axis]: Home Partners JV, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ (80.6)             (21.5)
Investment, Identifier [Axis]: Home Partners JV, Common Stock 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares               15,249,687 15,249,687 15,249,687 15,249,687 15,249,687 15,249,687 15,249,687  
Amortized cost               $ 22.9              
Fair value               $ (37.6)              
Investment, Identifier [Axis]: Home Partners JV, Common Stock, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [6],[23],[24],[32],[42]               32,659,547 32,659,547 32,659,547 32,659,547 32,659,547 32,659,547 32,659,547  
Amortized cost [23],[24],[32],[42]               $ 47.6              
Fair value [2],[23],[24],[32],[42]               (80.6)              
Investment, Identifier [Axis]: Home Partners JV, Private Equity                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value 0.0             (9.4)              
Investment, Identifier [Axis]: Home Partners JV, Private Equity 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               (9.4)             0.0
Investment, Identifier [Axis]: Home Partners JV, Private Equity 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               $ 0.0             0.0
Investment, Identifier [Axis]: Home Partners JV, Private Equity, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [6],[23],[24],[32],[42]               4,127,355 4,127,355 4,127,355 4,127,355 4,127,355 4,127,355 4,127,355  
Amortized cost [23],[24],[32],[42]               $ 5.4              
Fair value [2],[23],[24],[32],[42]               (9.4)              
Investment, Identifier [Axis]: Home Partners JV, Structured Mezzanine                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ (90.4)             (38.5)
Investment, Identifier [Axis]: Home Partners JV, Structured Mezzanine 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind               11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%  
Principal amount               $ 38.4              
Amortized cost               38.4              
Fair value               $ (38.4)              
Investment, Identifier [Axis]: Home Partners JV, Structured Mezzanine 1 | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind               11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%  
Investment, Identifier [Axis]: Home Partners JV, Structured Mezzanine, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [7],[24],[32],[42]               11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%  
Principal amount [6],[24],[32],[42]               $ 90.4              
Amortized cost [24],[32],[42]               85.6              
Fair value [2],[24],[32],[42]               $ (90.4)              
Investment, Identifier [Axis]: Home Partners JV, Structured Mezzanine, Real Estate | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [7],[24],[32],[42]               11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%  
Investment, Identifier [Axis]: Home Partners of America Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               $ 0.0             0.0
Investment, Identifier [Axis]: Home Partners of America Inc, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               0.0             (130.5)
Investment, Identifier [Axis]: Home Partners of America Inc, Warrant                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               $ 0.0             (2.1)
Investment, Identifier [Axis]: Hudson Technologies Co                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [24],[32]               10.25% 10.25% 10.25% 10.25% 10.25% 10.25% 10.25%  
Base rate floor [24],[32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[24],[32]               $ 79.9              
Amortized cost [24],[32]               72.3              
Fair value [2],[24],[32]               $ (82.1)              
Investment, Identifier [Axis]: Imagine Communications Corp, Common Stock, Media & Entertainment                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 33,034 [15],[28] 33,034 [15],[28] 33,034 [15],[28] 33,034 [15],[28] 33,034 [15],[28] 33,034 [15],[28] 33,034 [15],[28] 33,034 [23],[32] 33,034 [23],[32] 33,034 [23],[32] 33,034 [23],[32] 33,034 [23],[32] 33,034 [23],[32] 33,034 [23],[32]  
Amortized cost $ 3.8 [15],[28]             $ 3.8 [23],[32]              
Fair value $ (2.0) [1],[15],[28]             $ (2.5) [2],[23],[32]              
Investment, Identifier [Axis]: Individual FoodService, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[34],[40] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [34],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [17],[34],[40] $ 69.4                            
Amortized cost [34],[40] 66.1                            
Fair value [3],[34],[40] $ (68.7)                            
Investment, Identifier [Axis]: Individual FoodService, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 5.2                            
Amortized cost [15] 5.2                            
Fair value [3],[15] $ (5.2)                            
Investment, Identifier [Axis]: Individual FoodService, Capital Goods 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[40] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [15],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[40] $ 16.7                            
Amortized cost [15],[40] 16.7                            
Fair value [3],[15],[40] $ (16.6)                            
Investment, Identifier [Axis]: Individual FoodService, Capital Goods 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 5.4                            
Amortized cost [15] 5.4                            
Fair value [3],[15] $ (5.4)                            
Investment, Identifier [Axis]: Individual FoodService, Capital Goods 5                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 6.9                            
Amortized cost [15] 6.9                            
Fair value [3],[15] $ (6.8)                            
Investment, Identifier [Axis]: Individual FoodService, Capital Goods 6                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 4.8                            
Amortized cost [4] 4.7                            
Fair value [3],[4] $ (4.7)                            
Investment, Identifier [Axis]: Individual FoodService, Capital Goods 7                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 1.4                            
Amortized cost [4] 1.4                            
Fair value [3],[4] $ (1.4)                            
Investment, Identifier [Axis]: Individual FoodService, Senior Secured Loans—First Lien, Capital Goods , Maturing November 22, 2024 -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 0.2              
Amortized cost [32]               0.2              
Fair value [2],[32]               $ (0.2)              
Investment, Identifier [Axis]: Individual FoodService, Senior Secured Loans—First Lien, Capital Goods , Maturing November 22, 2024 -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 4.5              
Amortized cost [5]               4.5              
Fair value [2],[5]               $ (4.5)              
Investment, Identifier [Axis]: Individual FoodService, Senior Secured Loans—First Lien, Capital Goods , Maturing November 22, 2025 - 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 5.6              
Amortized cost [5]               5.6              
Fair value [2],[5]               $ (5.7)              
Investment, Identifier [Axis]: Individual FoodService, Senior Secured Loans—First Lien, Capital Goods , Maturing November 22, 2025 -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[33],[39]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [32],[33],[39]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[33],[39]               $ 90.8              
Amortized cost [32],[33],[39]               86.5              
Fair value [2],[32],[33],[39]               $ (91.7)              
Investment, Identifier [Axis]: Industria Chimica Emiliana Srl                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [24],[32]               7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25%  
Base rate floor [24],[32]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount [6],[24],[32]               $ 88.8              
Amortized cost [24],[32]               101.3              
Fair value [2],[24],[32]               $ (103.9)              
Investment, Identifier [Axis]: Industria Chimica Emiliana Srl | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount | €       € 113.9                      
Amortized cost $ 125.5                            
Fair value $ (117.1)                            
Investment, Identifier [Axis]: Industria Chimica Emiliana Srl 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               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%  
Principal amount | €                     € 113.9        
Amortized cost               $ 125.0              
Fair value               $ (133.3)              
Investment, Identifier [Axis]: Industria Chimica Emiliana Srl, Pharmaceuticals, Biotechnology & Life Sciences                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[29] 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25%                
Base rate floor [15],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | € [15],[17],[29]       € 88.8                      
Amortized cost [15],[29] $ 102.1                            
Fair value [3],[15],[29] $ (91.3)                            
Investment, Identifier [Axis]: Industry City TI Lessor LP                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[33]               10.80% 10.80% 10.80% 10.80% 10.80% 10.80% 10.80%  
Interest rate, paid in kind [32],[33]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[33]               $ 29.9              
Amortized cost [32],[33]               30.0              
Fair value [2],[32],[33]               $ (32.5)              
Investment, Identifier [Axis]: Industry City TI Lessor LP | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32],[33]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Investment, Identifier [Axis]: Industry City TI Lessor LP, Consumer Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15],[34] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[34] $ 25.6                            
Amortized cost [15],[34] 25.7                            
Fair value [3],[15],[34] $ (26.0)                            
Investment, Identifier [Axis]: Industry City TI Lessor LP, Consumer Services | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15],[34] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Investment, Identifier [Axis]: Insight Global LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 63.7             $ 37.9              
Amortized cost 62.9             37.5              
Fair value $ (61.8)             $ (37.4)              
Investment, Identifier [Axis]: Insight Global LLC, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 8.4                            
Amortized cost [15] 8.4                            
Fair value [3],[15] $ (8.2)                            
Investment, Identifier [Axis]: Insight Global LLC, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[16] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [15],[16] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[16],[17] $ 203.3                            
Amortized cost [15],[16] 201.5                            
Fair value [3],[15],[16] $ (197.0)                            
Investment, Identifier [Axis]: Insight Global LLC, Commercial & Professional Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 12.6                            
Amortized cost [4] 12.6                            
Fair value [3],[4] $ (12.2)                            
Investment, Identifier [Axis]: Insight Global LLC, Commercial & Professional Services 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 26.8                            
Amortized cost [4] 26.8                            
Fair value [3],[4] $ (26.0)                            
Investment, Identifier [Axis]: Insight Global LLC, Senior Secured Loans—First Lien, Commercial & Professional Services, Maturing September 22, 2027 -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[32]               $ 10.5              
Amortized cost [32]               10.5              
Fair value [2],[32]               $ (10.4)              
Investment, Identifier [Axis]: Insight Global LLC, Senior Secured Loans—First Lien, Commercial & Professional Services, Maturing September 22, 2027 -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 10.5              
Amortized cost [5]               10.5              
Fair value [2],[5]               $ (10.4)              
Investment, Identifier [Axis]: Insight Global LLC, Senior Secured Loans—First Lien, Commercial & Professional Services, Maturing September 22, 2028                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [10],[32]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [10],[32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[10],[32]               $ 230.0              
Amortized cost [10],[32]               227.8              
Fair value [2],[10],[32]               $ (227.2)              
Investment, Identifier [Axis]: Insight Global LLC, Senior Secured Loans—First Lien, Commercial & Professional Services, Maturing November 15, 2028                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 20.0              
Amortized cost [5]               20.0              
Fair value [2],[5]               $ (19.8)              
Investment, Identifier [Axis]: Integrity Marketing Group LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 145.3              
Amortized cost [5]               145.3              
Fair value [2],[5]               $ (143.2)              
Investment, Identifier [Axis]: Integrity Marketing Group LLC, Insurance                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 6.02% 6.02% 6.02% 6.02% 6.02% 6.02% 6.02%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 124.4                            
Amortized cost [15] 124.4                            
Fair value [3],[15] $ (122.4)                            
Investment, Identifier [Axis]: J S Held LLC, Insurance 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[16],[18],[34],[40] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [15],[16],[18],[34],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[16],[17],[18],[34],[40] $ 103.0                            
Amortized cost [15],[16],[18],[34],[40] 101.0                            
Fair value [3],[15],[16],[18],[34],[40] $ (101.8)                            
Investment, Identifier [Axis]: J S Held LLC, Insurance 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 8.9                            
Amortized cost [15] 8.7                            
Fair value [3],[15] $ (8.8)                            
Investment, Identifier [Axis]: J S Held LLC, Insurance 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 22.2                            
Amortized cost [15] 22.2                            
Fair value [3],[15] $ (22.0)                            
Investment, Identifier [Axis]: J S Held LLC, Insurance 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[18] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [15],[18] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[18] $ 24.8                            
Amortized cost [15],[18] 24.8                            
Fair value [3],[15],[18] $ (24.6)                            
Investment, Identifier [Axis]: J S Held LLC, Insurance 5                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 5.2                            
Amortized cost [4] 5.2                            
Fair value [3],[4] $ (5.2)                            
Investment, Identifier [Axis]: J S Held LLC, Insurance 6                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 19.2                            
Amortized cost [4] 19.2                            
Fair value [3],[4] (19.0)                            
Investment, Identifier [Axis]: J S Held LLC,, Senior Secured Loans—First Lien, Insurance -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [10],[32],[33],[39],[43]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [10],[32],[33],[39],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[10],[32],[33],[39],[43]               $ 165.4              
Amortized cost [10],[32],[33],[39],[43]               159.8              
Fair value [2],[10],[32],[33],[39],[43]               $ (167.1)              
Investment, Identifier [Axis]: J S Held LLC,, Senior Secured Loans—First Lien, Insurance -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 2.8              
Amortized cost [32]               2.6              
Fair value [2],[32]               $ (2.8)              
Investment, Identifier [Axis]: J S Held LLC,, Senior Secured Loans—First Lien, Insurance -3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 16.7              
Amortized cost [5]               16.7              
Fair value [2],[5]               $ (16.9)              
Investment, Identifier [Axis]: J S Held LLC,, Senior Secured Loans—First Lien, Insurance -4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 11.3              
Amortized cost [5]               11.3              
Fair value [2],[5]               (11.3)              
Investment, Identifier [Axis]: JW Aluminum Co                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [6],[31],[32],[33],[36]               76.5              
Amortized cost [31],[32],[33],[36]               75.5              
Fair value (78.1)             (81.0) [2],[31],[32],[33],[36]              
Investment, Identifier [Axis]: JW Aluminum Co 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value [58]               0.0             (41.8)
Investment, Identifier [Axis]: JW Aluminum Co 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value [57]               (81.0)             0.0
Investment, Identifier [Axis]: JW Aluminum Co, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (2.4)             $ 0.0 [57],[58]             0.0 [57],[58]
Investment, Identifier [Axis]: JW Aluminum Co, Common Stock, Materials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 2,105 [15],[28],[30],[53],[54] 2,105 [15],[28],[30],[53],[54] 2,105 [15],[28],[30],[53],[54] 2,105 [15],[28],[30],[53],[54] 2,105 [15],[28],[30],[53],[54] 2,105 [15],[28],[30],[53],[54] 2,105 [15],[28],[30],[53],[54] 2,105 [11],[23],[31],[32],[52] 2,105 [11],[23],[31],[32],[52] 2,105 [11],[23],[31],[32],[52] 2,105 [11],[23],[31],[32],[52] 2,105 [11],[23],[31],[32],[52] 2,105 [11],[23],[31],[32],[52] 2,105 [11],[23],[31],[32],[52]  
Amortized cost $ 0.0 [15],[28],[30],[53],[54]             $ 0.0 [11],[23],[31],[32],[52]              
Fair value (2.4) [1],[15],[28],[30],[53],[54]             0.0 [2],[11],[23],[31],[32],[52]              
Investment, Identifier [Axis]: JW Aluminum Co, Materials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [15],[17],[30],[34],[37] 76.5                            
Amortized cost [15],[30],[34],[37] 75.7                            
Fair value [3],[15],[30],[34],[37] (78.1)                            
Investment, Identifier [Axis]: JW Aluminum Co, Preferred Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (112.5) [59]             (122.6) [57],[59]             0.0 [57]
Investment, Identifier [Axis]: JW Aluminum Co, Preferred Stock 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value [58]               $ 0.0             $ (93.7)
Investment, Identifier [Axis]: JW Aluminum Co, Preferred Stock, Materials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 6.30% [12],[15],[30],[53],[54] 6.30% [12],[15],[30],[53],[54] 6.30% [12],[15],[30],[53],[54] 6.30% [12],[15],[30],[53],[54] 6.30% [12],[15],[30],[53],[54] 6.30% [12],[15],[30],[53],[54] 6.30% [12],[15],[30],[53],[54]               12.50% [7],[11],[31],[32],[52]
Number of shares | shares 15,279 [15],[30],[53],[54] 15,279 [15],[30],[53],[54] 15,279 [15],[30],[53],[54] 15,279 [15],[30],[53],[54] 15,279 [15],[30],[53],[54] 15,279 [15],[30],[53],[54] 15,279 [15],[30],[53],[54] 15,279 [11],[31],[32],[52] 15,279 [11],[31],[32],[52] 15,279 [11],[31],[32],[52] 15,279 [11],[31],[32],[52] 15,279 [11],[31],[32],[52] 15,279 [11],[31],[32],[52] 15,279 [11],[31],[32],[52]  
Amortized cost $ 200.1 [15],[30],[53],[54]             $ 177.9 [11],[31],[32],[52]              
Fair value $ (112.5) [1],[15],[30],[53],[54]             $ (122.6) [2],[11],[31],[32],[52]              
Investment, Identifier [Axis]: JW Aluminum Co, Preferred Stock, Materials | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 12.50% [12],[15],[30],[53],[54] 12.50% [12],[15],[30],[53],[54] 12.50% [12],[15],[30],[53],[54] 12.50% [12],[15],[30],[53],[54] 12.50% [12],[15],[30],[53],[54] 12.50% [12],[15],[30],[53],[54] 12.50% [12],[15],[30],[53],[54]               12.50% [7],[11],[31],[32],[52]
Investment, Identifier [Axis]: Jarrow Formulas Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[9],[10],[32],[33],[38],[39],[43]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [8],[9],[10],[32],[33],[39],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[8],[9],[10],[32],[33],[39],[43]               $ 186.6              
Amortized cost [8],[9],[10],[32],[33],[39],[43]               177.1              
Fair value [2],[8],[9],[10],[32],[33],[39],[43]               (190.3)              
Investment, Identifier [Axis]: Jarrow Formulas Inc, Household & Personal Products                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[14],[15],[16],[18],[19],[34],[40] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [13],[14],[15],[16],[18],[19],[34],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[14],[15],[16],[17],[18],[19],[34],[40] $ 181.8                            
Amortized cost [13],[14],[15],[16],[18],[19],[34],[40] 174.1                            
Fair value [3],[13],[14],[15],[16],[18],[19],[34],[40] (181.3)                            
Investment, Identifier [Axis]: Jet Edge International LLC, Preferred Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value 0.0             $ (16.8)             $ 0.0
Investment, Identifier [Axis]: Jet Edge International LLC, Preferred Stock, Transportation                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [7],[42],[49]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Number of shares | shares [6],[42],[49]               20,878,236 20,878,236 20,878,236 20,878,236 20,878,236 20,878,236 20,878,236  
Amortized cost [42],[49]               $ 20.9              
Fair value [2],[42],[49]               $ (16.8)              
Investment, Identifier [Axis]: Jet Edge International LLC, Preferred Stock, Transportation | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [7],[42],[49]               8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%  
Investment, Identifier [Axis]: Jet Edge International LLC, Term Loan                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ (75.6)             0.0
Investment, Identifier [Axis]: Jet Edge International LLC, Term Loan, Transportation 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 2.00% [12],[15] 2.00% [12],[15] 2.00% [12],[15] 2.00% [12],[15] 2.00% [12],[15] 2.00% [12],[15] 2.00% [12],[15] 2.00% [7],[32],[42] 2.00% [7],[32],[42] 2.00% [7],[32],[42] 2.00% [7],[32],[42] 2.00% [7],[32],[42] 2.00% [7],[32],[42] 2.00% [7],[32],[42]  
Principal amount $ 74.5 [15],[17]             $ 76.6 [6],[32],[42]              
Amortized cost 74.5 [15]             75.9 [32],[42]              
Fair value $ (76.7) [3],[15]             $ (76.1) [2],[32],[42]              
Investment, Identifier [Axis]: Jet Edge International LLC, Term Loan, Transportation 1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 2.00% [12],[15] 2.00% [12],[15] 2.00% [12],[15] 2.00% [12],[15] 2.00% [12],[15] 2.00% [12],[15] 2.00% [12],[15] 2.00% [7],[32],[42] 2.00% [7],[32],[42] 2.00% [7],[32],[42] 2.00% [7],[32],[42] 2.00% [7],[32],[42] 2.00% [7],[32],[42] 2.00% [7],[32],[42]  
Investment, Identifier [Axis]: Jet Edge International LLC, Term Loan, Transportation 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 2.00% [4],[12] 2.00% [4],[12] 2.00% [4],[12] 2.00% [4],[12] 2.00% [4],[12] 2.00% [4],[12] 2.00% [4],[12] 2.00% [5],[7],[42] 2.00% [5],[7],[42] 2.00% [5],[7],[42] 2.00% [5],[7],[42] 2.00% [5],[7],[42] 2.00% [5],[7],[42] 2.00% [5],[7],[42]  
Principal amount $ 0.7 [4],[17]             $ 75.0 [5],[6],[42]              
Amortized cost 0.7 [4]             75.0 [5],[42]              
Fair value $ (0.7) [3],[4]             $ (74.5) [2],[5],[42]              
Investment, Identifier [Axis]: Jet Edge International LLC, Term Loan, Transportation 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 2.00% [4],[12] 2.00% [4],[12] 2.00% [4],[12] 2.00% [4],[12] 2.00% [4],[12] 2.00% [4],[12] 2.00% [4],[12] 2.00% [5],[7],[42] 2.00% [5],[7],[42] 2.00% [5],[7],[42] 2.00% [5],[7],[42] 2.00% [5],[7],[42] 2.00% [5],[7],[42] 2.00% [5],[7],[42]  
Investment, Identifier [Axis]: Jet Edge International LLC, Warrant                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ (4.5)             0.0
Investment, Identifier [Axis]: Jet Edge International LLC, Warrant, Transportation                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [6],[23],[42],[46]               3,963,000,000 3,963,000,000 3,963,000,000 3,963,000,000 3,963,000,000 3,963,000,000 3,963,000,000  
Amortized cost [23],[42],[46]               $ 0.0              
Fair value [2],[23],[42],[46]               $ (4.5)              
Investment, Identifier [Axis]: Jones Apparel Holdings, Inc., Common Stock, Consumer Durables & Apparel                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 5,451 [15],[28] 5,451 [15],[28] 5,451 [15],[28] 5,451 [15],[28] 5,451 [15],[28] 5,451 [15],[28] 5,451 [15],[28] 5,451 [23],[32] 5,451 [23],[32] 5,451 [23],[32] 5,451 [23],[32] 5,451 [23],[32] 5,451 [23],[32] 5,451 [23],[32]  
Amortized cost $ 0.9 [15],[28]             $ 0.9 [23],[32]              
Fair value $ 0.0 [1],[15],[28]             $ 0.0 [2],[23],[32]              
Investment, Identifier [Axis]: KBP Investments LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Base rate floor               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount               $ 23.7              
Amortized cost               23.6              
Fair value               $ (23.5)              
Investment, Identifier [Axis]: KBP Investments LLC 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Interest rate, paid in kind 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 $ 23.6                            
Amortized cost 23.5                            
Fair value $ (21.9)                            
Investment, Identifier [Axis]: KBP Investments LLC 1 | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Investment, Identifier [Axis]: KBP Investments LLC, Senior Secured Loans—First Lien, Food & Staples Retailing -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Base rate floor [32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[32]               $ 23.6              
Amortized cost [32]               22.9              
Fair value [2],[32]               $ (23.3)              
Investment, Identifier [Axis]: KBP Investments LLC, Senior Secured Loans—First Lien, Food & Staples Retailing -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 3.9              
Amortized cost [5]               3.9              
Fair value [2],[5]               (3.8)              
Investment, Identifier [Axis]: KKR Altitude II Offshore Aggregator LP, Partnership Interest                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (44.4)             0.0              
Investment, Identifier [Axis]: KKR Altitude II Offshore Aggregator LP, Partnership Interest, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [15],[28],[29],[30] 44,424,346 44,424,346 44,424,346 44,424,346 44,424,346 44,424,346 44,424,346                
Amortized cost [15],[28],[29],[30] $ 44.4                            
Fair value [3],[15],[28],[29],[30] (44.4)                            
Investment, Identifier [Axis]: KKR Central Park Leasing Aggregator L.P., Partnership Interest, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount 39.1 [15],[17],[25],[28],[29]             39.1 [6],[20],[23],[24],[32]              
Amortized cost 39.1 [15],[25],[28],[29]             39.1 [20],[23],[24],[32]              
Fair value $ (16.3) [3],[15],[25],[28],[29]             $ (25.8) [2],[20],[23],[24],[32]              
Investment, Identifier [Axis]: KKR Chord IP Aggregator LP, Partnership Interest Common Stock | 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                
Amortized cost $ 22.9                            
Fair value $ (21.1)                            
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 [15],[29] 89,453,083 [15],[29] 89,453,083 [15],[29] 89,453,083 [15],[29] 89,453,083 [15],[29] 89,453,083 [15],[29] 89,453,083 [15],[29] 114,193,861 [6],[24],[32] 114,193,861 [6],[24],[32] 114,193,861 [6],[24],[32] 114,193,861 [6],[24],[32] 114,193,861 [6],[24],[32] 114,193,861 [6],[24],[32] 114,193,861 [6],[24],[32]  
Amortized cost $ 89.5 [15],[29]             $ 112.6 [24],[32]              
Fair value $ (96.3) [3],[15],[29]             (131.5) [2],[24],[32]              
Investment, Identifier [Axis]: KKR Chord IP Aggregator LP, Structured Mezzanine, Media & Entertainment                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [6],[24],[32]               167.3              
Amortized cost [24],[32]               164.9              
Fair value [2],[24],[32]               (167.3)              
Investment, Identifier [Axis]: KKR Residential Opportunities I LLC, Private Equity, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [15],[28] 17,510,867 17,510,867 17,510,867 17,510,867 17,510,867 17,510,867 17,510,867                
Amortized cost [15],[28] $ 17.5                            
Fair value [3],[15],[28] (17.6)                            
Investment, Identifier [Axis]: KKR Rocket Loans Aggregator LLC, Partnership Interest                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (4.3)             $ (1.4)             0.0
Investment, Identifier [Axis]: KKR Rocket Loans Aggregator LLC, Partnership Interest, Diversified Financials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 4,336,415 [15],[29],[30] 4,336,415 [15],[29],[30] 4,336,415 [15],[29],[30] 4,336,415 [15],[29],[30] 4,336,415 [15],[29],[30] 4,336,415 [15],[29],[30] 4,336,415 [15],[29],[30] 1,387,913 [6],[24],[31],[32] 1,387,913 [6],[24],[31],[32] 1,387,913 [6],[24],[31],[32] 1,387,913 [6],[24],[31],[32] 1,387,913 [6],[24],[31],[32] 1,387,913 [6],[24],[31],[32] 1,387,913 [6],[24],[31],[32]  
Amortized cost $ 4.3 [15],[29],[30]             $ 1.4 [24],[31],[32]              
Fair value $ (4.3) [3],[15],[29],[30]             $ (1.4) [2],[24],[31],[32]              
Investment, Identifier [Axis]: KKR Zeno Aggregator LP (K2 Aviation), Partnership Interest | 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                
Amortized cost $ 24.4                            
Fair value $ (16.6)                            
Investment, Identifier [Axis]: KKR Zeno Aggregator LP (K2 Aviation), Partnership Interest 1 | 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  
Amortized cost               $ 24.4              
Fair value               $ (15.9)              
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 [15],[28],[29] 23,664,954 [15],[28],[29] 23,664,954 [15],[28],[29] 23,664,954 [15],[28],[29] 23,664,954 [15],[28],[29] 23,664,954 [15],[28],[29] 23,664,954 [15],[28],[29] 23,664,954 [6],[23],[24],[32] 23,664,954 [6],[23],[24],[32] 23,664,954 [6],[23],[24],[32] 23,664,954 [6],[23],[24],[32] 23,664,954 [6],[23],[24],[32] 23,664,954 [6],[23],[24],[32] 23,664,954 [6],[23],[24],[32]  
Amortized cost $ 23.0 [15],[28],[29]             $ 23.0 [23],[24],[32]              
Fair value $ (20.0) [3],[15],[28],[29]             $ (19.1) [2],[23],[24],[32]              
Investment, Identifier [Axis]: Karman Space Inc, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[40] 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%                
Base rate floor [15],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[40] $ 51.1                            
Amortized cost [15],[40] 48.9                            
Fair value [3],[15],[40] $ (49.7)                            
Investment, Identifier [Axis]: Karman Space Inc, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 4.5                            
Amortized cost [15] 4.3                            
Fair value [3],[15] $ (4.4)                            
Investment, Identifier [Axis]: Karman Space Inc, Capital Goods 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 37.1                            
Amortized cost [15] 36.6                            
Fair value [3],[15] $ (36.1)                            
Investment, Identifier [Axis]: Karman Space Inc, Capital Goods 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 1.0                            
Amortized cost [4] 1.0                            
Fair value [3],[4] $ (0.9)                            
Investment, Identifier [Axis]: Karman Space Inc, Senior Secured Loans—First Lien, Capital Goods -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[39]               6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%  
Base rate floor [32],[39]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[39]               $ 92.4              
Amortized cost [32],[39]               88.8              
Fair value [2],[32],[39]               $ (94.2)              
Investment, Identifier [Axis]: Karman Space Inc, Senior Secured Loans—First Lien, Capital Goods -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 4.4              
Amortized cost [32]               4.2              
Fair value [2],[32]               $ (4.4)              
Investment, Identifier [Axis]: Karman Space Inc, Senior Secured Loans—First Lien, Capital Goods -3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 1.1              
Amortized cost [5]               1.1              
Fair value [2],[5]               $ (1.1)              
Investment, Identifier [Axis]: Kellermeyer Bergensons Services LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               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%  
Principal amount               $ 29.5              
Amortized cost               28.1              
Fair value               $ (29.6)              
Investment, Identifier [Axis]: Kellermeyer Bergensons Services LLC 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 29.2                            
Amortized cost 28.1                            
Fair value $ (26.5)                            
Investment, Identifier [Axis]: Kellermeyer Bergensons Services LLC, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[14],[15],[16],[18],[19],[34],[40] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [13],[14],[15],[16],[18],[19],[34],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[14],[15],[16],[17],[18],[19],[34],[40] $ 268.9                            
Amortized cost [13],[14],[15],[16],[18],[19],[34],[40] 259.5                            
Fair value [3],[13],[14],[15],[16],[18],[19],[34],[40] $ (244.6)                            
Investment, Identifier [Axis]: Kellermeyer Bergensons Services LLC, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 84.6                            
Amortized cost [15] 84.1                            
Fair value [3],[15] $ (77.0)                            
Investment, Identifier [Axis]: Kellermeyer Bergensons Services LLC, Commercial & Professional Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 15.4                            
Amortized cost [15] 15.3                            
Fair value [3],[15] (14.0)                            
Investment, Identifier [Axis]: Kellermeyer Bergensons Services LLC, Senior Secured Loans—First Lien, Commercial & Professional Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[9],[10],[32],[33],[38],[39],[43]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [8],[9],[10],[32],[33],[38],[39],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[8],[9],[10],[32],[33],[38],[39],[43]               $ 341.7              
Amortized cost [8],[9],[10],[32],[33],[38],[39],[43]               329.6              
Fair value [2],[8],[9],[10],[32],[33],[38],[39],[43]               $ (342.8)              
Investment, Identifier [Axis]: Kellermeyer Bergensons Services LLC, Senior Secured Loans—First Lien, Commercial & Professional Services -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 31.0              
Amortized cost [5]               31.0              
Fair value [2],[5]               $ (31.1)              
Investment, Identifier [Axis]: Kettle Cuisine LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75%  
Base rate floor               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount               $ 16.4              
Amortized cost               16.4              
Fair value               (15.6)              
Investment, Identifier [Axis]: Kilter Finance, Preferred Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (99.5)             $ (36.1)             (0.2)
Investment, Identifier [Axis]: Kilter Finance, Preferred Stock | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 12.00% 12.00% 12.00% 12.00% 12.00% 12.00% 12.00%                
Principal amount $ 24.0                            
Amortized cost 24.0                            
Fair value $ (24.0)                            
Investment, Identifier [Axis]: Kilter Finance, Preferred Stock, Insurance                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 12.00% [12],[15],[29],[30] 12.00% [12],[15],[29],[30] 12.00% [12],[15],[29],[30] 12.00% [12],[15],[29],[30] 12.00% [12],[15],[29],[30] 12.00% [12],[15],[29],[30] 12.00% [12],[15],[29],[30] 6.00% [7],[24],[31],[32] 6.00% [7],[24],[31],[32] 6.00% [7],[24],[31],[32] 6.00% [7],[24],[31],[32] 6.00% [7],[24],[31],[32] 6.00% [7],[24],[31],[32] 6.00% [7],[24],[31],[32]  
Number of shares | shares 99,400,000 [15],[29],[30] 99,400,000 [15],[29],[30] 99,400,000 [15],[29],[30] 99,400,000 [15],[29],[30] 99,400,000 [15],[29],[30] 99,400,000 [15],[29],[30] 99,400,000 [15],[29],[30] 36,108,611 [6],[24],[31],[32] 36,108,611 [6],[24],[31],[32] 36,108,611 [6],[24],[31],[32] 36,108,611 [6],[24],[31],[32] 36,108,611 [6],[24],[31],[32] 36,108,611 [6],[24],[31],[32] 36,108,611 [6],[24],[31],[32]  
Amortized cost $ 98.6 [15],[29],[30]             $ 34.6 [24],[31],[32]              
Fair value (99.5) [3],[15],[29],[30]             $ (36.1) [2],[24],[31],[32]              
Investment, Identifier [Axis]: Kilter Finance, Preferred Stock, Insurance | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [7],[24],[31],[32]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Investment, Identifier [Axis]: Kilter Finance, Private Equity                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (0.5)             $ (0.5)             $ (0.2)
Investment, Identifier [Axis]: Kilter Finance, Private Equity, Insurance                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 536,709 [15],[28],[29],[30] 536,709 [15],[28],[29],[30] 536,709 [15],[28],[29],[30] 536,709 [15],[28],[29],[30] 536,709 [15],[28],[29],[30] 536,709 [15],[28],[29],[30] 536,709 [15],[28],[29],[30] 536,709 [6],[23],[24],[31],[32] 536,709 [6],[23],[24],[31],[32] 536,709 [6],[23],[24],[31],[32] 536,709 [6],[23],[24],[31],[32] 536,709 [6],[23],[24],[31],[32] 536,709 [6],[23],[24],[31],[32] 536,709 [6],[23],[24],[31],[32]  
Amortized cost $ 0.5 [15],[28],[29],[30]             $ 0.5 [23],[24],[31],[32]              
Fair value $ (0.5) [3],[15],[28],[29],[30]             $ (0.5) [2],[23],[24],[31],[32]              
Investment, Identifier [Axis]: Lakefield Veterinary Group | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 27.1                            
Amortized cost 26.7                            
Fair value $ (25.9)                            
Investment, Identifier [Axis]: Lakefield Veterinary Group, Health Care Equipment & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[16],[18] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [15],[16],[18] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[16],[17],[18] $ 108.3                            
Amortized cost [15],[16],[18] 107.6                            
Fair value [3],[15],[16],[18] $ (103.8)                            
Investment, Identifier [Axis]: Lakefield Veterinary Group, Health Care Equipment & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 35.2                            
Amortized cost [4] 35.2                            
Fair value [3],[4] $ (33.7)                            
Investment, Identifier [Axis]: Lakefield Veterinary Group, Senior Secured Loans—First Lien, Consumer Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [10],[32]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [10],[32],[43]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[10],[32],[43]               $ 115.6              
Amortized cost [10],[32],[43]               114.5              
Fair value [2],[10],[32],[43]               $ (114.6)              
Investment, Identifier [Axis]: Lakefield Veterinary Group, Senior Secured Loans—First Lien, Consumer Services -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 56.3              
Amortized cost [5]               56.3              
Fair value [2],[5]               $ (55.7)              
Investment, Identifier [Axis]: Lakeview Farms Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 15.5             $ 15.7              
Amortized cost 15.4             15.6              
Fair value $ (15.0)             $ (15.6)              
Investment, Identifier [Axis]: Lakeview Farms Inc, Food, Beverage & Tobacco 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[14],[15],[40] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [14],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [14],[17],[40] $ 31.2                            
Amortized cost [14],[40] 29.6                            
Fair value [3],[14],[40] $ (30.2)                            
Investment, Identifier [Axis]: Lakeview Farms Inc, Food, Beverage & Tobacco 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 4.5                            
Amortized cost [15] 4.5                            
Fair value [3],[15] $ (4.3)                            
Investment, Identifier [Axis]: Lakeview Farms Inc, Food, Beverage & Tobacco 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [15],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[40] $ 45.0                            
Amortized cost [15],[40] 45.0                            
Fair value [3],[15],[40] $ (43.6)                            
Investment, Identifier [Axis]: Lakeview Farms Inc, Food, Beverage & Tobacco 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 10.8                            
Amortized cost [4] 10.8                            
Fair value [3],[4] $ (10.5)                            
Investment, Identifier [Axis]: Lakeview Farms Inc, Food, Beverage & Tobacco 5                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 2.3                            
Amortized cost [4] 2.3                            
Fair value [3],[4] $ (2.2)                            
Investment, Identifier [Axis]: Lakeview Farms Inc, Senior Secured Loans—First Lien, Food, Beverage & Tobacco -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [9],[32],[39]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [9],[32],[39]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[9],[32],[39]               $ 77.0              
Amortized cost [9],[32],[39]               75.1              
Fair value [2],[9],[32],[39]               $ (76.5)              
Investment, Identifier [Axis]: Lakeview Farms Inc, Senior Secured Loans—First Lien, Food, Beverage & Tobacco -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 3.4              
Amortized cost [32]               3.4              
Fair value [2],[32]               $ (3.4)              
Investment, Identifier [Axis]: Lakeview Farms Inc, Senior Secured Loans—First Lien, Food, Beverage & Tobacco -3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 10.8              
Amortized cost [5]               10.8              
Fair value [2],[5]               $ (10.8)              
Investment, Identifier [Axis]: Lakeview Farms Inc, Senior Secured Loans—First Lien, Food, Beverage & Tobacco -4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 3.4              
Amortized cost [5]               3.4              
Fair value [2],[5]               $ (3.4)              
Investment, Identifier [Axis]: Lenovo Group Ltd, Structured Mezzanine 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 7.80% 7.80% 7.80% 7.80% 7.80% 7.80% 7.80%  
Base rate floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount $ 4.7                   € 6.9        
Amortized cost 4.7             $ 8.1              
Fair value $ (4.7)             $ (7.9)              
Investment, Identifier [Axis]: Lenovo Group Ltd, Structured Mezzanine 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 7.80% 7.80% 7.80% 7.80% 7.80% 7.80% 7.80%  
Base rate floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount       € 3.6       $ 10.7              
Amortized cost $ 3.6             10.7              
Fair value $ (3.9)             $ (10.7)              
Investment, Identifier [Axis]: Lenovo Group Ltd, Structured Mezzanine 3 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 11.80% 11.80% 11.80% 11.80% 11.80% 11.80% 11.80%  
Base rate floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount | €       € 5.0             € 4.8        
Amortized cost $ 5.0             $ 5.6              
Fair value $ (5.4)             $ (5.4)              
Investment, Identifier [Axis]: Lenovo Group Ltd, Structured Mezzanine 4 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 11.80% 11.80% 11.80% 11.80% 11.80% 11.80% 11.80%  
Base rate floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount | £         £ 1.1             £ 1.3      
Amortized cost $ 1.3             $ 1.8              
Fair value $ (1.4)             $ (1.7)              
Investment, Identifier [Axis]: Lenovo Group Ltd, Structured Mezzanine 5 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 7.80% 7.80% 7.80% 7.80% 7.80% 7.80% 7.80%  
Base rate floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount $ 6.5                     £ 1.9      
Amortized cost 6.5             $ 2.6              
Fair value $ (6.5)             $ (2.5)              
Investment, Identifier [Axis]: Lenovo Group Ltd, Structured Mezzanine 6 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 10.50% 11.80% 11.80% 11.80% 11.80% 11.80% 11.80% 11.80%  
Base rate floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount       € 0.8       $ 7.4              
Amortized cost $ 0.9             7.4              
Fair value $ (1.0)             (7.4)              
Investment, Identifier [Axis]: Lenovo Group Ltd, Structured Mezzanine, Technology Hardware & Equipment 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount | € [6],[24],[32]                     € 7.8        
Amortized cost [24],[32]               9.2              
Fair value [2],[24],[32]               (8.9)              
Investment, Identifier [Axis]: Lenovo Group Ltd, Structured Mezzanine, Technology Hardware & Equipment 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [6],[24],[32]               12.1              
Amortized cost [24],[32]               12.1              
Fair value [2],[24],[32]               (12.1)              
Investment, Identifier [Axis]: Lenovo Group Ltd, Structured Mezzanine, Technology Hardware & Equipment 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount | € [6],[24],[32]                     € 5.9        
Amortized cost [24],[32]               6.9              
Fair value [2],[24],[32]               (6.7)              
Investment, Identifier [Axis]: Lenovo Group Ltd, Structured Mezzanine, Technology Hardware & Equipment 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount | £ [6],[24],[32]                       £ 1.6      
Amortized cost [24],[32]               2.2              
Fair value [2],[24],[32]               (2.1)              
Investment, Identifier [Axis]: Lenovo Group Ltd, Structured Mezzanine, Technology Hardware & Equipment 5                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount | £ [6],[24],[32]                       £ 2.1      
Amortized cost [24],[32]               2.9              
Fair value [2],[24],[32]               (2.9)              
Investment, Identifier [Axis]: Lenovo Group Ltd, Structured Mezzanine, Technology Hardware & Equipment 6                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [6],[24],[32]               9.1              
Amortized cost [24],[32]               9.1              
Fair value [2],[24],[32]               $ (9.1)              
Investment, Identifier [Axis]: Lexitas Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%                
Base rate floor 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount $ 18.5                            
Amortized cost 18.4                            
Fair value $ (18.2)                            
Investment, Identifier [Axis]: Lexitas Inc 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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               $ 8.0              
Amortized cost               7.9              
Fair value               $ (8.1)              
Investment, Identifier [Axis]: Lexitas Inc 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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               $ 10.7              
Amortized cost               10.7              
Fair value               $ (10.8)              
Investment, Identifier [Axis]: Lexitas Inc, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%                
Base rate floor [13],[14],[15],[16],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[14],[15],[16],[17],[40] $ 133.1                            
Amortized cost [13],[14],[15],[16],[40] 130.2                            
Fair value [3],[13],[14],[15],[16],[40] $ (131.1)                            
Investment, Identifier [Axis]: Lexitas Inc, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[14],[15],[16],[40] 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 8.4                            
Amortized cost [4] 8.4                            
Fair value [3],[4] $ (8.3)                            
Investment, Identifier [Axis]: Lexitas Inc, Senior Secured Loans—First Lien, Commercial & Professional Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[9],[10],[32],[39]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [8],[9],[10],[32],[39]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[8],[9],[10],[32],[39]               $ 106.8              
Amortized cost [8],[9],[10],[32],[39]               103.3              
Fair value [2],[8],[9],[10],[32],[39]               $ (107.8)              
Investment, Identifier [Axis]: Lexitas Inc, Senior Secured Loans—First Lien, Commercial & Professional Services -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 10.3              
Amortized cost [5]               10.3              
Fair value [2],[5]               $ (10.4)              
Investment, Identifier [Axis]: Lexitas Inc, Senior Secured Loans—First Lien, Commercial & Professional Services -3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 5.4              
Amortized cost [5]               5.4              
Fair value [2],[5]               $ (5.4)              
Investment, Identifier [Axis]: Lionbridge Technologies Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[33],[38],[43]               7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%  
Base rate floor [8],[9],[32],[39],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[8],[9],[32],[39],[43]               $ 68.9              
Amortized cost [8],[9],[32],[39],[43]               64.0              
Fair value [2],[8],[9],[32],[39],[43]               $ (70.3)              
Investment, Identifier [Axis]: Lionbridge Technologies Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 26.8                            
Amortized cost 26.3                            
Fair value $ (26.9)                            
Investment, Identifier [Axis]: Lionbridge Technologies Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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               $ 28.3              
Amortized cost               27.7              
Fair value               $ (28.9)              
Investment, Identifier [Axis]: Lionbridge Technologies Inc, Media & Entertainment                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[15],[18],[19],[34],[40] 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%                
Base rate floor [13],[15],[18],[19],[34],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[15],[17],[18],[19],[34],[40] $ 122.7                            
Amortized cost [13],[15],[18],[19],[34],[40] 119.0                            
Fair value [3],[13],[15],[18],[19],[34],[40] $ (123.4)                            
Investment, Identifier [Axis]: Lipari Foods LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[33],[39],[43]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [32],[33],[39],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[33],[39],[43]               $ 272.0              
Amortized cost [32],[33],[39],[43]               261.2              
Fair value [2],[32],[33],[39],[43]               $ (272.0)              
Investment, Identifier [Axis]: Lipari Foods LLC 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               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%  
Principal amount               $ 65.3              
Amortized cost               65.2              
Fair value               $ (65.4)              
Investment, Identifier [Axis]: Lipari Foods LLC, Common Stock, Food & Staples Retailing                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [15],[28] 7,936,123 7,936,123 7,936,123 7,936,123 7,936,123 7,936,123 7,936,123                
Amortized cost [15],[28] $ 8.0                            
Fair value [1],[15],[28] $ (8.0)                            
Investment, Identifier [Axis]: Lipari Foods LLC, Food & Staples Retailing 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[18],[34],[40] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [15],[16],[18] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[16],[17],[18] $ 96.0                            
Amortized cost [15],[16],[18] 94.6                            
Fair value [3],[15],[16],[18] $ (94.9)                            
Investment, Identifier [Axis]: Lipari Foods LLC, Food & Staples Retailing 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[18],[34] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 27.3                            
Amortized cost [4] 27.3                            
Fair value [3],[4] $ (27.0)                            
Investment, Identifier [Axis]: Lloyd's Register Quality Assurance Ltd                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5],[24]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Interest rate, paid in kind [5],[24]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base rate floor [5],[24]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | £ [5],[6],[24]                       £ 15.0      
Amortized cost [5],[24]               $ 20.0              
Fair value [2],[5],[24]               $ (19.7)              
Investment, Identifier [Axis]: Lloyd's Register Quality Assurance Ltd | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [5],[24]               6.30% 6.30% 6.30% 6.30% 6.30% 6.30% 6.30%  
Investment, Identifier [Axis]: Lloyd's Register Quality Assurance Ltd 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Interest rate, paid in kind               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base rate floor               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | €                     € 44.3        
Amortized cost               $ 48.6              
Fair value               $ (48.9)              
Investment, Identifier [Axis]: Lloyd's Register Quality Assurance Ltd 1 | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind               6.30% 6.30% 6.30% 6.30% 6.30% 6.30% 6.30%  
Investment, Identifier [Axis]: Lloyd's Register Quality Assurance Ltd, Consumer Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[29] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Interest rate, paid in kind [12],[15],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor [15],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | £ [15],[17],[29]         £ 5.7                    
Amortized cost [15],[29] $ 7.4                            
Fair value [3],[15],[29] $ (6.7)                            
Investment, Identifier [Axis]: Lloyd's Register Quality Assurance Ltd, Consumer Services 1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15],[29] 2.90% 2.90% 2.90% 2.90% 2.90% 2.90% 2.90%                
Investment, Identifier [Axis]: Lloyd's Register Quality Assurance Ltd, Consumer Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12],[29] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Interest rate, paid in kind [4],[12],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor [4],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | £ [4],[17],[29]         £ 9.3                    
Amortized cost [4],[29] $ 12.6                            
Fair value [3],[4],[29] $ (12.3)                            
Investment, Identifier [Axis]: Lloyd's Register Quality Assurance Ltd, Consumer Services 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [4],[12],[29] 2.90% 2.90% 2.90% 2.90% 2.90% 2.90% 2.90%                
Investment, Identifier [Axis]: Lrqa Ltd | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Interest rate, paid in kind 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | €       € 44.3                      
Amortized cost $ 48.8                            
Fair value $ (45.9)                            
Investment, Identifier [Axis]: Lrqa Ltd | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 6.30% 6.30% 6.30% 6.30% 6.30% 6.30% 6.30%                
Investment, Identifier [Axis]: Luxembourg Life Fund - Absolute Return Fund I, 1L Term Loan | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               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%  
Principal amount               $ 26.8              
Amortized cost               26.9              
Fair value               $ (27.1)              
Investment, Identifier [Axis]: Luxembourg Life Fund - Absolute Return Fund I, 1L Term Loan | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 21.3                            
Amortized cost 21.3                            
Fair value $ (21.3)                            
Investment, Identifier [Axis]: Luxembourg Life Fund - Absolute Return Fund II, Structured Mezzanine, Insurance                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[29] 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%                
Base rate floor [15],[29] 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount [15],[17],[29] $ 24.9                            
Amortized cost [15],[29] 24.9                            
Fair value [3],[15],[29] $ (24.6)                            
Investment, Identifier [Axis]: Luxembourg Life Fund - Absolute Return Fund III, Term Loan | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 56.2             $ 57.5              
Amortized cost 55.8             57.0              
Fair value $ (57.0)             $ (57.0)              
Investment, Identifier [Axis]: Luxembourg Life Fund - Long Term Growth Fund, Term Loan | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount $ 67.4             $ 94.6              
Amortized cost 67.4             94.1              
Fair value $ (68.4)             $ (94.5)              
Investment, Identifier [Axis]: MB Precision Holdings LLC, Class A - 2 Units, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 8,081,288 [28],[51],[55] 8,081,288 [28],[51],[55] 8,081,288 [28],[51],[55] 8,081,288 [28],[51],[55] 8,081,288 [28],[51],[55] 8,081,288 [28],[51],[55] 8,081,288 [28],[51],[55] 8,081,288 [23],[50],[56] 8,081,288 [23],[50],[56] 8,081,288 [23],[50],[56] 8,081,288 [23],[50],[56] 8,081,288 [23],[50],[56] 8,081,288 [23],[50],[56] 8,081,288 [23],[50],[56]  
Amortized cost $ 0.5 [28],[51],[55]             $ 0.5 [23],[50],[56]              
Fair value $ 0.0 [1],[28],[51],[55]             $ 0.0 [2],[23],[50],[56]              
Investment, Identifier [Axis]: MB2 Dental Solutions LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 11.9                            
Amortized cost 11.8                            
Fair value $ (11.7)                            
Investment, Identifier [Axis]: MB2 Dental Solutions LLC, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[14],[15],[19],[40] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [13],[14],[15],[19],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[14],[15],[17],[19],[40] $ 268.0                            
Amortized cost [13],[14],[15],[19],[40] 259.2                            
Fair value [3],[13],[14],[15],[19],[40] $ (263.6)                            
Investment, Identifier [Axis]: MB2 Dental Solutions LLC, Senior Secured Loans—First Lien, Health Care Equipment & Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[9],[32],[38],[39]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [8],[9],[32],[38],[39]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[8],[9],[32],[38],[39]               $ 231.0              
Amortized cost [8],[9],[32],[38],[39]               220.3              
Fair value [2],[8],[9],[32],[38],[39]               $ (231.7)              
Investment, Identifier [Axis]: MB2 Dental Solutions LLC, Senior Secured Loans—First Lien, Health Care Equipment & Services -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 56.7              
Amortized cost [5]               56.7              
Fair value [2],[5]               $ (56.9)              
Investment, Identifier [Axis]: Magna Legal Services LLC, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 18.5                            
Amortized cost [15] 18.2                            
Fair value [3],[15] $ (18.2)                            
Investment, Identifier [Axis]: Magna Legal Services LLC, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 2.2                            
Amortized cost [4] 2.2                            
Fair value [3],[4] $ (2.1)                            
Investment, Identifier [Axis]: Magna Legal Services LLC, Commercial & Professional Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 5.2                            
Amortized cost [4] 5.2                            
Fair value [3],[4] $ (5.1)                            
Investment, Identifier [Axis]: Magna Legal Services LLC, Common Stock, Commercial & Professional Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [28],[47] 4,938,192 4,938,192 4,938,192 4,938,192 4,938,192 4,938,192 4,938,192                
Amortized cost [28],[47] $ 4.9                            
Fair value [1],[28],[47] $ (4.9)                            
Investment, Identifier [Axis]: Matchesfashion Ltd                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [24],[32]               4.63% 4.63% 4.63% 4.63% 4.63% 4.63% 4.63%  
Interest rate, paid in kind [24],[32]               3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00%  
Base rate floor [24],[32]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount [6],[24],[32]               $ 12.9              
Amortized cost [24],[32]               12.4              
Fair value [2],[24],[32]               $ (8.2)              
Investment, Identifier [Axis]: Matchesfashion Ltd | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [24],[32]               3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00%  
Investment, Identifier [Axis]: Matchesfashion Ltd, Consumer Durables & Apparel                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[25],[28],[29] 4.63% 4.63% 4.63% 4.63% 4.63% 4.63% 4.63%                
Interest rate, paid in kind [12],[15],[25],[28],[29] 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00%                
Base rate floor [15],[25],[28],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount [15],[17],[25],[28],[29] $ 13.3                            
Amortized cost [15],[25],[28],[29] 12.2                            
Fair value [3],[15],[25],[28],[29] $ (4.8)                            
Investment, Identifier [Axis]: Matchesfashion Ltd, Consumer Durables & Apparel | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15],[25],[28],[29] 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00%                
Investment, Identifier [Axis]: Maverick Natural Resources LLC, Common Stock, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 259,211 [51],[55] 259,211 [51],[55] 259,211 [51],[55] 259,211 [51],[55] 259,211 [51],[55] 259,211 [51],[55] 259,211 [51],[55] 259,211 [23],[50],[56] 259,211 [23],[50],[56] 259,211 [23],[50],[56] 259,211 [23],[50],[56] 259,211 [23],[50],[56] 259,211 [23],[50],[56] 259,211 [23],[50],[56]  
Amortized cost $ 84.6 [51],[55]             $ 84.5 [23],[50],[56]              
Fair value $ (160.9) [1],[51],[55]             $ (143.6) [2],[23],[50],[56]              
Investment, Identifier [Axis]: Med-Metrix | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 11.9                            
Amortized cost 11.9                            
Fair value $ (12.0)                            
Investment, Identifier [Axis]: Med-Metrix, Common Stock, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 29,403 [28],[47] 29,403 [28],[47] 29,403 [28],[47] 29,403 [28],[47] 29,403 [28],[47] 29,403 [28],[47] 29,403 [28],[47] 29,403 [23],[46] 29,403 [23],[46] 29,403 [23],[46] 29,403 [23],[46] 29,403 [23],[46] 29,403 [23],[46] 29,403 [23],[46]  
Amortized cost $ 1.5 [28],[47]             $ 1.5 [23],[46]              
Fair value $ (2.9) [1],[28],[47]             $ (1.6) [2],[23],[46]              
Investment, Identifier [Axis]: Med-Metrix, Preferred Stock, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 8.00% [12],[47] 8.00% [12],[47] 8.00% [12],[47] 8.00% [12],[47] 8.00% [12],[47] 8.00% [12],[47] 8.00% [12],[47]               8.00% [7],[46]
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 [23],[32] 29,403 [23],[32] 29,403 [23],[32] 29,403 [23],[32] 29,403 [23],[32] 29,403 [23],[32] 29,403 [23],[32]  
Amortized cost $ 1.5 [47]             $ 1.5 [23],[32]              
Fair value $ (1.5) [1],[47]             $ (1.5) [2],[23],[32]              
Investment, Identifier [Axis]: Med-Metrix, Preferred Stock, Software & Services | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 8.00% [12],[47] 8.00% [12],[47] 8.00% [12],[47] 8.00% [12],[47] 8.00% [12],[47] 8.00% [12],[47] 8.00% [12],[47]               8.00% [7],[46]
Investment, Identifier [Axis]: Med-Metrix, Senior Secured Loans—First Lien, Software & Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 62.4              
Amortized cost [32]               61.8              
Fair value [2],[32]               $ (61.9)              
Investment, Identifier [Axis]: Med-Metrix, Senior Secured Loans—First Lien, Software & Services -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 31.3              
Amortized cost [5]               31.3              
Fair value [2],[5]               $ (31.0)              
Investment, Identifier [Axis]: Med-Metrix, Senior Secured Loans—First Lien, Software & Services -3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 7.8              
Amortized cost [5]               7.8              
Fair value [2],[5]               $ (7.8)              
Investment, Identifier [Axis]: Med-Metrix, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [15],[16],[19] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[16],[17],[19] $ 56.1                            
Amortized cost [15],[16],[19] 56.1                            
Fair value [3],[15],[16],[19] $ (56.6)                            
Investment, Identifier [Axis]: Med-Metrix, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 25.0                            
Amortized cost [4] 25.0                            
Fair value [3],[4] $ (25.3)                            
Investment, Identifier [Axis]: Med-Metrix, Software & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 7.8                            
Amortized cost [4] 7.8                            
Fair value [3],[4] $ (7.8)                            
Investment, Identifier [Axis]: Medallia Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32]               6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%  
Base rate floor [32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[32]               $ 147.9              
Amortized cost [32]               146.5              
Fair value [2],[32]               $ (146.5)              
Investment, Identifier [Axis]: Medallia Inc | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32]               6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%  
Investment, Identifier [Axis]: Medallia Inc, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 3.25% 3.25% 3.25% 3.25% 3.25% 3.25% 3.25%                
Interest rate, paid in kind [12],[15] 3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 207.8                            
Amortized cost [15] 205.8                            
Fair value [3],[15] $ (203.0)                            
Investment, Identifier [Axis]: Medallia Inc, Software & Services | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15] 3.30% 3.30% 3.30% 3.30% 3.30% 3.30% 3.30%                
Investment, Identifier [Axis]: Miami Beach Medical Group LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[9],[32],[38],[39]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base rate floor [8],[9],[32],[38],[39]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[8],[9],[32],[38],[39]               $ 180.6              
Amortized cost [8],[9],[32],[38],[39]               171.4              
Fair value [2],[8],[9],[32],[38],[39]               $ (178.6)              
Investment, Identifier [Axis]: Miami Beach Medical Group LLC, Common Stock, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 5,000,000 [15],[28] 5,000,000 [15],[28] 5,000,000 [15],[28] 5,000,000 [15],[28] 5,000,000 [15],[28] 5,000,000 [15],[28] 5,000,000 [15],[28] 5,000,000 [23],[32] 5,000,000 [23],[32] 5,000,000 [23],[32] 5,000,000 [23],[32] 5,000,000 [23],[32] 5,000,000 [23],[32] 5,000,000 [23],[32]  
Amortized cost $ 4.8 [15],[28]             $ 4.8 [23],[32]              
Fair value $ 0.0 [1],[15],[28]             $ (3.9) [2],[23],[32]              
Investment, Identifier [Axis]: Miami Beach Medical Group LLC, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[14],[15],[19],[40] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Interest rate, paid in kind [12],[13],[14],[15],[19],[40] 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50%                
Base rate floor [15],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[40] $ 164.4                            
Amortized cost [15],[40] 157.1                            
Fair value [3],[15],[40] $ (139.8)                            
Investment, Identifier [Axis]: Miami Beach Medical Group LLC, Health Care Equipment & Services | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[13],[14],[15],[19],[40] 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50%                
Investment, Identifier [Axis]: Micronics Filtration Holdings Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32],[42]               7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%  
Principal amount [6],[32],[42]               $ 51.4              
Amortized cost [32],[42]               46.0              
Fair value $ 0.0             $ (51.0) [2],[32],[42]             $ (35.5)
Investment, Identifier [Axis]: Micronics Filtration Holdings Inc | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32],[42]               7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%  
Investment, Identifier [Axis]: Micronics Filtration Holdings Inc, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value 0.0             $ 0.0             0.0
Investment, Identifier [Axis]: Micronics Filtration Holdings Inc, Common Stock, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [23],[32],[42]               53,073 53,073 53,073 53,073 53,073 53,073 53,073  
Amortized cost [23],[32],[42]               $ 0.6              
Fair value [2],[23],[32],[42]               0.0              
Investment, Identifier [Axis]: Micronics Filtration Holdings Inc, Preferred Stock, Series A                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value 0.0             $ (0.1)             0.0
Investment, Identifier [Axis]: Micronics Filtration Holdings Inc, Preferred Stock, Series A, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [23],[32],[42]               55 55 55 55 55 55 55  
Amortized cost [23],[32],[42]               $ 0.6              
Fair value [2],[23],[32],[42]               (0.1)              
Investment, Identifier [Axis]: Micronics Filtration Holdings Inc, Preferred Stock, Series B                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value 0.0             (0.4)             0.0
Investment, Identifier [Axis]: Micronics Filtration Holdings Inc, Preferred Stock, Series B PIK                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value 0.0             $ (11.9)             0.0
Investment, Identifier [Axis]: Micronics Filtration Holdings Inc, Preferred Stock, Series B PIK, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [23],[32],[42]               112,780 112,780 112,780 112,780 112,780 112,780 112,780  
Amortized cost [23],[32],[42]               $ 0.0              
Fair value [2],[23],[32],[42]               $ (11.9)              
Investment, Identifier [Axis]: Micronics Filtration Holdings Inc, Preferred Stock, Series B, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [23],[32],[42]               23 23 23 23 23 23 23  
Amortized cost [23],[32],[42]               $ 0.2              
Fair value [2],[23],[32],[42]               (0.4)              
Investment, Identifier [Axis]: Micronics Filtration Holdings Inc, Preferred Stock, Series C PIK                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ (6.2)             0.0
Investment, Identifier [Axis]: Micronics Filtration Holdings Inc, Preferred Stock, Series C PIK, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [23],[32],[42]               54,000 54,000 54,000 54,000 54,000 54,000 54,000  
Amortized cost [23],[32],[42]               $ 0.0              
Fair value [2],[23],[32],[42]               $ (6.2)              
Investment, Identifier [Axis]: Misys Ltd                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [24],[32],[36]               7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25%  
Base rate floor [24],[32],[36]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[24],[32],[36]               $ 21.8              
Amortized cost [24],[32],[36]               20.5              
Fair value [2],[24],[32],[36]               $ (21.8)              
Investment, Identifier [Axis]: Misys Ltd | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 46.6                            
Amortized cost 44.6                            
Fair value $ (35.1)                            
Investment, Identifier [Axis]: Misys Ltd 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 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 $ 2.3             $ 41.2              
Amortized cost 2.2             38.8              
Fair value $ (2.0)             $ (41.2)              
Investment, Identifier [Axis]: Misys Ltd, Preferred Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 10.25% 10.25% 10.25% 10.25% 10.25% 10.25% 10.25%                
Investment, Identifier [Axis]: Misys Ltd, Preferred Stock | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Base rate floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Number of shares | shares 25,265,621 25,265,621 25,265,621 25,265,621 25,265,621 25,265,621 25,265,621                
Amortized cost $ 24.8                            
Fair value $ (21.1)                            
Investment, Identifier [Axis]: Misys Ltd, Preferred Stock | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 10.25% 10.25% 10.25% 10.25% 10.25% 10.25% 10.25%                
Investment, Identifier [Axis]: Misys Ltd, Preferred Stock, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 10.25% [12],[15],[29] 10.25% [12],[15],[29] 10.25% [12],[15],[29] 10.25% [12],[15],[29] 10.25% [12],[15],[29] 10.25% [12],[15],[29] 10.25% [12],[15],[29] 102500.00% [7],[24],[32] 102500.00% [7],[24],[32] 102500.00% [7],[24],[32] 102500.00% [7],[24],[32] 102500.00% [7],[24],[32] 102500.00% [7],[24],[32] 102500.00% [7],[24],[32]  
Base rate floor [15],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Number of shares | shares 65,200,765 [15],[29] 65,200,765 [15],[29] 65,200,765 [15],[29] 65,200,765 [15],[29] 65,200,765 [15],[29] 65,200,765 [15],[29] 65,200,765 [15],[29] 79,782,377 [24],[32] 79,782,377 [24],[32] 79,782,377 [24],[32] 79,782,377 [24],[32] 79,782,377 [24],[32] 79,782,377 [24],[32] 79,782,377 [24],[32]  
Amortized cost $ 61.1 [15],[29]             $ 73.5 [24],[32]              
Fair value $ (61.1) [1],[15],[29]             $ (78.9) [2],[24],[32]              
Investment, Identifier [Axis]: Misys Ltd, Preferred Stock, Software & Services | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 10.25% [12],[15],[29] 10.25% [12],[15],[29] 10.25% [12],[15],[29] 10.25% [12],[15],[29] 10.25% [12],[15],[29] 10.25% [12],[15],[29] 10.25% [12],[15],[29] 102500.00% [7],[24],[32] 102500.00% [7],[24],[32] 102500.00% [7],[24],[32] 102500.00% [7],[24],[32] 102500.00% [7],[24],[32] 102500.00% [7],[24],[32] 102500.00% [7],[24],[32]  
Investment, Identifier [Axis]: Misys Ltd, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25%                
Base rate floor [15],[29],[37] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[29],[37] $ 16.3                            
Amortized cost [15],[29],[37] 15.6                            
Fair value [3],[15],[29],[37] $ (12.3)                            
Investment, Identifier [Axis]: Monitronics International Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Base rate floor               1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50%  
Principal amount               $ 35.5              
Amortized cost               32.9              
Fair value               $ (35.6)              
Investment, Identifier [Axis]: Monitronics International Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 35.5                            
Amortized cost 33.7                            
Fair value $ (33.7)                            
Investment, Identifier [Axis]: Monitronics International Inc, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[37] 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%                
Base rate floor [15],[18],[37] 1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30%                
Principal amount [15],[17],[18],[37] $ 18.6                            
Amortized cost [15],[18],[37] 17.7                            
Fair value [3],[15],[18],[37] $ (12.5)                            
Investment, Identifier [Axis]: Monitronics International Inc, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [15] 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50%                
Principal amount [15],[17] $ 46.1                            
Amortized cost [15] 44.3                            
Fair value [3],[15] $ (42.3)                            
Investment, Identifier [Axis]: Monitronics International Inc, Commercial & Professional Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [4] 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50%                
Principal amount [4],[17] $ 23.9                            
Amortized cost [4] 23.9                            
Fair value [3],[4] $ (21.9)                            
Investment, Identifier [Axis]: Monitronics International Inc, Senior Secured Loans—First Lien, Commercial & Professional Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[36],[43]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base rate floor [32],[36],[43]               1.30% 1.30% 1.30% 1.30% 1.30% 1.30% 1.30%  
Principal amount [6],[32],[36],[43]               $ 18.8              
Amortized cost [32],[36],[43]               17.2              
Fair value [2],[32],[36],[43]               $ (17.7)              
Investment, Identifier [Axis]: Monitronics International Inc, Senior Secured Loans—First Lien, Commercial & Professional Services -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Base rate floor [32]               1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50%  
Principal amount [6],[32]               $ 47.3              
Amortized cost [32]               44.8              
Fair value [2],[32]               $ (45.1)              
Investment, Identifier [Axis]: Monitronics International Inc, Senior Secured Loans—First Lien, Commercial & Professional Services -3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Base rate floor [5]               1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50%  
Principal amount [5],[6]               $ 22.7              
Amortized cost [5]               22.7              
Fair value [2],[5]               $ (21.6)              
Investment, Identifier [Axis]: Motion Recruitment Partners LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 24.8             $ 25.0              
Amortized cost 24.5             24.7              
Fair value $ (24.6)             $ (24.7)              
Investment, Identifier [Axis]: Motion Recruitment Partners LLC, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[16],[18] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [15],[16],[18] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[16],[17],[18] $ 64.0                            
Amortized cost [15],[16],[18] 64.0                            
Fair value [3],[15],[16],[18] $ (63.6)                            
Investment, Identifier [Axis]: Motion Recruitment Partners LLC, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[19],[40] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [15],[19],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[19],[40] $ 59.4                            
Amortized cost [15],[19],[40] 55.8                            
Fair value [3],[15],[19],[40] $ (59.0)                            
Investment, Identifier [Axis]: Motion Recruitment Partners LLC, Commercial & Professional Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 59.6                            
Amortized cost [4] 59.6                            
Fair value [3],[4] $ (59.2)                            
Investment, Identifier [Axis]: Motion Recruitment Partners LLC, Senior Secured Loans—First Lien, Commercial & Professional Services - 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [10],[32],[38],[39],[43]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base rate floor [10],[32],[38],[39],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[10],[32],[38],[39],[43]               $ 119.9              
Amortized cost [10],[32],[38],[39],[43]               115.5              
Fair value [2],[10],[32],[38],[39],[43]               $ (118.4)              
Investment, Identifier [Axis]: Motion Recruitment Partners LLC, Senior Secured Loans—First Lien, Commercial & Professional Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 4.8              
Amortized cost [32]               4.5              
Fair value [2],[32]               $ (4.7)              
Investment, Identifier [Axis]: Motion Recruitment Partners LLC, Senior Secured Loans—First Lien, Commercial & Professional Services -3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 59.6              
Amortized cost [5]               59.6              
Fair value [2],[5]               (58.9)              
Investment, Identifier [Axis]: My Community Homes PropCo 2, Private Equity | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 34.7                            
Fair value $ (32.5)                            
Investment, Identifier [Axis]: My Community Homes PropCo 2, Private Equity, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [15],[28],[29],[30] 84,291,667 84,291,667 84,291,667 84,291,667 84,291,667 84,291,667 84,291,667                
Amortized cost [15],[28],[29],[30] $ 84.3                            
Fair value [3],[15],[28],[29],[30] (79.0)                            
Investment, Identifier [Axis]: My Community Homes SFR PropCo 2, Private Equity                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (79.0)             $ (33.0)             0.0
Investment, Identifier [Axis]: My Community Homes SFR PropCo 2, Private Equity, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [6],[23],[24],[31],[32]               33,000,000 33,000,000 33,000,000 33,000,000 33,000,000 33,000,000 33,000,000  
Amortized cost [23],[24],[31],[32]               $ 33.0              
Fair value [2],[23],[24],[31],[32]               $ (33.0)              
Investment, Identifier [Axis]: NBG Home                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 67.7              
Amortized cost [32]               67.6              
Fair value [2],[32]               $ (53.3)              
Investment, Identifier [Axis]: NBG Home 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[32]               12.75% 12.75% 12.75% 12.75% 12.75% 12.75% 12.75%  
Base rate floor [20],[23],[32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[20],[23],[32]               $ 31.4              
Amortized cost [20],[23],[32]               28.2              
Fair value [2],[20],[23],[32]               $ (8.5)              
Investment, Identifier [Axis]: NBG Home 1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[32]               12.75% 12.75% 12.75% 12.75% 12.75% 12.75% 12.75%  
Investment, Identifier [Axis]: NBG Home, Common Stock, Consumer Durables & Apparel                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 1,903 [15],[28] 1,903 [15],[28] 1,903 [15],[28] 1,903 [15],[28] 1,903 [15],[28] 1,903 [15],[28] 1,903 [15],[28] 1,903 [23],[32] 1,903 [23],[32] 1,903 [23],[32] 1,903 [23],[32] 1,903 [23],[32] 1,903 [23],[32] 1,903 [23],[32]  
Amortized cost $ 2.4 [15],[28]             $ 2.6 [23],[32]              
Fair value $ 0.0 [1],[15],[28]             $ 0.0 [2],[23],[32]              
Investment, Identifier [Axis]: NBG Home, Consumer Durables & Apparel 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[25],[28] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [15],[25],[28] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[25],[28] $ 75.9                            
Amortized cost [15],[25],[28] 69.9                            
Fair value [3],[15],[25],[28] $ (21.2)                            
Investment, Identifier [Axis]: NBG Home, Consumer Durables & Apparel 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 12.75% 12.75% 12.75% 12.75% 12.75% 12.75% 12.75%                
Base rate floor [15],[25],[28] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[25],[28] $ 35.8                            
Amortized cost [15],[25],[28] 28.2                            
Fair value [3],[15],[25],[28] 0.0                            
Investment, Identifier [Axis]: NCI Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%  
Interest rate, paid in kind [32]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 78.8              
Amortized cost [32]               77.7              
Fair value [2],[32]               $ (72.0)              
Investment, Identifier [Axis]: NCI Inc | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32]               2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%  
Investment, Identifier [Axis]: NCI Inc 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value (28.1)             $ 0.0              
Investment, Identifier [Axis]: NCI Inc, Class A-1 Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value [59] $ 0.0             0.0              
Investment, Identifier [Axis]: NCI Inc, Class A-1 Common Stock, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [15],[28],[30] 42,923 42,923 42,923 42,923 42,923 42,923 42,923                
Amortized cost [15],[28],[30] $ 0.0                            
Fair value [1],[15],[28],[30] 0.0                            
Investment, Identifier [Axis]: NCI Inc, Class B-1 Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value [59] $ 0.0             0.0              
Investment, Identifier [Axis]: NCI Inc, Class B-1 Common Stock, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [15],[28],[30] 30,121 30,121 30,121 30,121 30,121 30,121 30,121                
Amortized cost [15],[28],[30] $ 0.0                            
Fair value [1],[15],[28],[30] 0.0                            
Investment, Identifier [Axis]: NCI Inc, Class C Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value [59] $ (20.2)             0.0              
Investment, Identifier [Axis]: NCI Inc, Class C Common Stock, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [15],[28],[30] 49,406 49,406 49,406 49,406 49,406 49,406 49,406                
Amortized cost [15],[28],[30] $ 20.2                            
Fair value [1],[15],[28],[30] (20.2)                            
Investment, Identifier [Axis]: NCI Inc, Class I-1 Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value [59] $ 0.0             $ 0.0              
Investment, Identifier [Axis]: NCI Inc, Class I-1 Common Stock, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [15],[28],[30] 42,923 42,923 42,923 42,923 42,923 42,923 42,923                
Amortized cost [15],[28],[30] $ 0.0                            
Fair value [1],[15],[28],[30] $ 0.0                            
Investment, Identifier [Axis]: NCI Inc, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%                
Base rate floor [15],[30] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[30] $ 28.1                            
Amortized cost [15],[30] 28.7                            
Fair value [3],[15],[30] $ (28.1)                            
Investment, Identifier [Axis]: NCI Inc, Software & Services | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15] 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%                
Investment, Identifier [Axis]: NEP Broadcasting LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 6.8             $ 6.8              
Amortized cost 6.7             6.7              
Fair value $ (5.1)             $ (6.7)              
Investment, Identifier [Axis]: NPD Group Inc/The, Consumer Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 0.1                            
Amortized cost [15] 0.1                            
Fair value [3],[15] $ (0.1)                            
Investment, Identifier [Axis]: NPD Group Inc/The, Consumer Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50%                
Interest rate, paid in kind [12],[15] 2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 19.2                            
Amortized cost [15] 19.2                            
Fair value [3],[15] $ (19.2)                            
Investment, Identifier [Axis]: NPD Group Inc/The, Consumer Services 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15] 2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80%                
Investment, Identifier [Axis]: NPD Group Inc/The, Consumer Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 0.9                            
Amortized cost [4] 0.9                            
Fair value [3],[4] $ (0.9)                            
Investment, Identifier [Axis]: Net Documents, Senior Secured Loans—First Lien, Software & Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 24.6              
Amortized cost [32]               24.4              
Fair value [2],[32]               $ (24.3)              
Investment, Identifier [Axis]: Net Documents, Senior Secured Loans—First Lien, Software & Services -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 0.9              
Amortized cost [32]               0.9              
Fair value [2],[32]               $ (0.9)              
Investment, Identifier [Axis]: Net Documents, Senior Secured Loans—First Lien, Software & Services -3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 2.1              
Amortized cost [5]               2.1              
Fair value [2],[5]               $ (2.0)              
Investment, Identifier [Axis]: Net Documents, Senior Secured Loans—First Lien, Software & Services -4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 7.4              
Amortized cost [5]               7.3              
Fair value [2],[5]               $ (7.3)              
Investment, Identifier [Axis]: Net Documents, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 33.0                            
Amortized cost [15] 32.8                            
Fair value [3],[15] $ (32.0)                            
Investment, Identifier [Axis]: Net Documents, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 3.0                            
Amortized cost [4] 2.9                            
Fair value [3],[4] $ (2.9)                            
Investment, Identifier [Axis]: New Era Technology Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 34.3             $ 10.0              
Amortized cost 33.8             10.0              
Fair value $ (33.7)             $ (10.0)              
Investment, Identifier [Axis]: New Era Technology Inc, Senior Secured Loans—First Lien, Software & Services - 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 13.8              
Amortized cost [5]               13.8              
Fair value [2],[5]               $ (13.7)              
Investment, Identifier [Axis]: New Era Technology Inc, Senior Secured Loans—First Lien, Software & Services - 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 3.1              
Amortized cost [5]               3.1              
Fair value [2],[5]               $ (3.1)              
Investment, Identifier [Axis]: New Era Technology Inc, Senior Secured Loans—First Lien, Software & Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [9],[10],[32],[38],[39]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [9],[10],[32],[38],[39]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[9],[10],[32],[38],[39]               $ 82.5              
Amortized cost [9],[10],[32],[38],[39]               78.6              
Fair value [2],[9],[10],[32],[38],[39]               $ (82.1)              
Investment, Identifier [Axis]: New Era Technology Inc, Senior Secured Loans—First Lien, Software & Services -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 1.6              
Amortized cost [32]               1.5              
Fair value [2],[32]               $ (1.6)              
Investment, Identifier [Axis]: New Era Technology Inc, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[14],[15],[16],[19],[40] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [14],[16],[19],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [14],[16],[17],[19],[40] $ 51.1                            
Amortized cost [14],[16],[19],[40] 49.4                            
Fair value [3],[14],[16],[19],[40] $ (50.2)                            
Investment, Identifier [Axis]: New Era Technology Inc, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 2.6                            
Amortized cost [15] 2.5                            
Fair value [3],[15] $ (2.5)                            
Investment, Identifier [Axis]: New Era Technology Inc, Software & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 2.1                            
Amortized cost [4] 2.1                            
Fair value [3],[4] $ (2.1)                            
Investment, Identifier [Axis]: NewStar Clarendon 2014-1A Class D | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 17.80% 17.80% 17.80% 17.80% 17.80% 17.80% 17.80%                
Principal amount $ 30.0                            
Amortized cost 9.3                            
Fair value (12.7)                            
Investment, Identifier [Axis]: NewStar Clarendon 2014-1A Class D 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               18.30% 18.30% 18.30% 18.30% 18.30% 18.30% 18.30%  
Investment, Identifier [Axis]: NewStar Clarendon 2014-1A Class D 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount               $ 30.0              
Amortized cost               9.3              
Fair value               (15.3)              
Investment, Identifier [Axis]: NewStar Clarendon 2014-1A Class D, Diversified Financials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount 8.3 [15],[17],[29]             8.3 [6],[24],[32]              
Amortized cost 2.5 [15],[29]             2.5 [24],[32]              
Fair value $ (3.5) [3],[15],[29]             $ (4.2) [2],[24],[32]              
Investment, Identifier [Axis]: Nine West Holdings Inc, Common Stock, Consumer Durables & Apparel                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 5,451 [15],[28] 5,451 [15],[28] 5,451 [15],[28] 5,451 [15],[28] 5,451 [15],[28] 5,451 [15],[28] 5,451 [15],[28] 5,451 [23],[32] 5,451 [23],[32] 5,451 [23],[32] 5,451 [23],[32] 5,451 [23],[32] 5,451 [23],[32] 5,451 [23],[32]  
Amortized cost $ 6.4 [15],[28]             $ 6.5 [23],[32]              
Fair value $ 0.0 [1],[15],[28]             $ 0.0 [2],[23],[32]              
Investment, Identifier [Axis]: Novotech Pty Ltd 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 24.4                            
Amortized cost 23.9                            
Fair value $ (23.6)                            
Investment, Identifier [Axis]: Novotech Pty Ltd 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount           $ 33.7                  
Amortized cost $ 24.8                            
Fair value $ (22.1)                            
Investment, Identifier [Axis]: Novotech Pty Ltd, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12],[29] 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%                
Base rate floor [4],[29] 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount [4],[17],[29] $ 5.7                            
Amortized cost [4],[29] 5.6                            
Fair value [3],[4],[29] $ (5.5)                            
Investment, Identifier [Axis]: OEConnection LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 8.25% 8.25% 8.25% 8.25% 8.25% 8.25% 8.25%  
Base rate floor 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%  
Principal amount $ 50.0             $ 50.0              
Amortized cost 50.0             50.0              
Fair value $ (48.4)             $ (49.1)              
Investment, Identifier [Axis]: OEConnection LLC, Senior Secured Loans—Second Lien, Software & Services - 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%  
Base rate floor [32]               0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount [6],[32]               $ 49.0              
Amortized cost [32]               49.0              
Fair value [2],[32]               $ (48.1)              
Investment, Identifier [Axis]: OEConnection LLC, Senior Secured Loans—Second Lien, Software & Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[43]               8.25% 8.25% 8.25% 8.25% 8.25% 8.25% 8.25%  
Base rate floor [32],[43]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount [6],[32],[43]               $ 27.0              
Amortized cost [32],[43]               26.6              
Fair value [2],[32],[43]               $ (26.5)              
Investment, Identifier [Axis]: OEConnection LLC, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%                
Base rate floor [15],[18] 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount [15],[17],[18] $ 76.1                            
Amortized cost [15],[18] 75.7                            
Fair value [3],[15],[18] $ (73.6)                            
Investment, Identifier [Axis]: Omnimax International Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[9],[10],[32],[39],[43]               7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25%  
Base rate floor [8],[9],[10],[32],[39],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[8],[9],[10],[32],[39],[43]               $ 218.5              
Amortized cost [8],[9],[10],[32],[39],[43]               209.2              
Fair value [2],[8],[9],[10],[32],[39],[43]               (217.0)              
Investment, Identifier [Axis]: Omnimax International Inc, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[14],[15],[16],[18],[40] 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%                
Base rate floor [13],[14],[15],[16],[18],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[14],[15],[16],[17],[18],[40] $ 183.6                            
Amortized cost [13],[14],[15],[16],[18],[40] 176.6                            
Fair value [3],[13],[14],[15],[16],[18],[40] $ (175.0)                            
Investment, Identifier [Axis]: One Call Care Management Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value [58]               $ 0.0             (4.7)
Investment, Identifier [Axis]: One Call Care Management Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%                
Principal amount $ 25.6                            
Amortized cost 25.0                            
Fair value $ (20.9)                            
Investment, Identifier [Axis]: One Call Care Management Inc | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%                
Investment, Identifier [Axis]: One Call Care Management Inc 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[36]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [31],[32],[36]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[31],[32],[36]               $ 5.0              
Amortized cost [31],[32],[36]               4.7              
Fair value $ 0.0 [60]             $ (5.0) [2],[31],[32],[36],[60]             0.0
Investment, Identifier [Axis]: One Call Care Management Inc 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 4.9                            
Amortized cost 5.0                            
Fair value (4.1)                            
Investment, Identifier [Axis]: One Call Care Management Inc 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [30],[32]               8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%  
Principal amount [6],[31],[32]               $ 23.5              
Amortized cost [31],[32]               21.6              
Fair value $ 0.0 [60]             $ (23.5) [2],[31],[32],[57],[60]             0.0 [57]
Investment, Identifier [Axis]: One Call Care Management Inc 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00%                
Interest rate, paid in kind               8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%  
Base rate floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount $ 2.1             $ 23.5              
Amortized cost 1.9             22.9              
Fair value $ (2.1)             $ (23.5)              
Investment, Identifier [Axis]: One Call Care Management Inc 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [30],[32]               8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%  
Investment, Identifier [Axis]: One Call Care Management Inc 2 | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind               8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%  
Investment, Identifier [Axis]: One Call Care Management Inc 3 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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               $ 5.0              
Amortized cost               5.0              
Fair value               (5.0)              
Investment, Identifier [Axis]: One Call Care Management Inc, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value [58]               0.0             (2.4)
Investment, Identifier [Axis]: One Call Care Management Inc, Common Stock | 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                
Amortized cost $ 2.2                            
Fair value (1.9)                            
Investment, Identifier [Axis]: One Call Care Management Inc, Common Stock 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0 [60]             $ (2.4) [57],[60]             0.0 [57]
Investment, Identifier [Axis]: One Call Care Management Inc, Common Stock 1 | 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  
Amortized cost               $ 2.2              
Fair value               $ (2.4)              
Investment, Identifier [Axis]: One Call Care Management Inc, Common Stock, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 34,872 [15],[28] 34,872 [15],[28] 34,872 [15],[28] 34,872 [15],[28] 34,872 [15],[28] 34,872 [15],[28] 34,872 [15],[28] 34,872 [23],[31],[32] 34,872 [23],[31],[32] 34,872 [23],[31],[32] 34,872 [23],[31],[32] 34,872 [23],[31],[32] 34,872 [23],[31],[32] 34,872 [23],[31],[32]  
Amortized cost $ 2.1 [15],[28]             $ 2.1 [23],[31],[32]              
Fair value $ (1.9) [1],[15],[28]             (2.4) [2],[23],[31],[32]              
Investment, Identifier [Axis]: One Call Care Management Inc, Health Care Equipment & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[30],[37] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [15],[37] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17],[37] $ 4.9                            
Amortized cost [15],[37] 4.7                            
Fair value [3],[15],[37] $ (4.1)                            
Investment, Identifier [Axis]: One Call Care Management Inc, Health Care Equipment & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%                
Principal amount [15],[17] $ 25.6                            
Amortized cost [15] 23.9                            
Fair value [3],[15] $ (20.9)                            
Investment, Identifier [Axis]: One Call Care Management Inc, Health Care Equipment & Services 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%                
Investment, Identifier [Axis]: One Call Care Management Inc, Preferred Stock A                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0 [60]             $ (26.1) [57],[60]             0.0 [57]
Investment, Identifier [Axis]: One Call Care Management Inc, Preferred Stock A | 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                
Amortized cost $ 23.7                            
Fair value $ (20.6)                            
Investment, Identifier [Axis]: One Call Care Management Inc, Preferred Stock A 2 | 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  
Amortized cost               $ 23.7              
Fair value               (26.1)              
Investment, Identifier [Axis]: One Call Care Management Inc, Preferred Stock A 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value [58]               $ 0.0             (25.5)
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 371,992 [15],[28] 371,992 [15],[28] 371,992 [15],[28] 371,992 [15],[28] 371,992 [15],[28] 371,992 [15],[28] 371,992 [15],[28] 371,992 [23],[31],[32] 371,992 [23],[31],[32] 371,992 [23],[31],[32] 371,992 [23],[31],[32] 371,992 [23],[31],[32] 371,992 [23],[31],[32] 371,992 [23],[31],[32]  
Amortized cost $ 22.8 [15],[28]             $ 22.8 [23],[31],[32]              
Fair value $ (20.5) [1],[15],[28]             (26.1) [2],[23],[31],[32]              
Investment, Identifier [Axis]: One Call Care Management Inc, Preferred Stock B                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%                
Fair value $ 0.0 [60]             $ (9.2) [57],[60]             0.0 [57]
Investment, Identifier [Axis]: One Call Care Management Inc, Preferred Stock B | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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                
Amortized cost $ 8.7                            
Fair value $ (7.7)                            
Investment, Identifier [Axis]: One Call Care Management Inc, Preferred Stock B | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%                
Investment, Identifier [Axis]: One Call Care Management Inc, Preferred Stock B 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind               9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%  
Fair value [58]               $ 0.0             (10.6)
Investment, Identifier [Axis]: One Call Care Management Inc, Preferred Stock B 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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  
Amortized cost               $ 8.8              
Fair value               $ (9.2)              
Investment, Identifier [Axis]: One Call Care Management Inc, Preferred Stock B 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind               9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%  
Investment, Identifier [Axis]: One Call Care Management Inc, Preferred Stock B, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 9.00% [12],[15] 9.00% [12],[15] 9.00% [12],[15] 9.00% [12],[15] 9.00% [12],[15] 9.00% [12],[15] 9.00% [12],[15] 9.00% [7],[31],[32] 9.00% [7],[31],[32] 9.00% [7],[31],[32] 9.00% [7],[31],[32] 9.00% [7],[31],[32] 9.00% [7],[31],[32] 9.00% [7],[31],[32]  
Number of shares | shares 7,672,347 [15] 7,672,347 [15] 7,672,347 [15] 7,672,347 [15] 7,672,347 [15] 7,672,347 [15] 7,672,347 [15] 7,672,347 [31],[32] 7,672,347 [31],[32] 7,672,347 [31],[32] 7,672,347 [31],[32] 7,672,347 [31],[32] 7,672,347 [31],[32] 7,672,347 [31],[32]  
Amortized cost $ 8.0 [15]             $ 8.0 [31],[32]              
Fair value $ (7.7) [1],[15]             $ (9.2) [2],[31],[32]              
Investment, Identifier [Axis]: One Call Care Management Inc, Preferred Stock B, Health Care Equipment & Services | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 9.00% [12],[15] 9.00% [12],[15] 9.00% [12],[15] 9.00% [12],[15] 9.00% [12],[15] 9.00% [12],[15] 9.00% [12],[15] 9.00% [7],[31],[32] 9.00% [7],[31],[32] 9.00% [7],[31],[32] 9.00% [7],[31],[32] 9.00% [7],[31],[32] 9.00% [7],[31],[32] 9.00% [7],[31],[32]  
Investment, Identifier [Axis]: Ontic Engineering & Manufacturing Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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               $ 2.1              
Amortized cost               1.9              
Fair value               (2.1)              
Investment, Identifier [Axis]: Opendoor Labs Inc, Structured Mezzanine, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [15],[17],[29] $ 71.1                            
Amortized cost [15],[29] 71.1                            
Fair value [3],[15],[29] (66.4)                            
Investment, Identifier [Axis]: Opendoor Labs Inc, Structured Mezzanine, Real Estate 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [6],[24],[32]               71.1              
Amortized cost [24],[32]               71.1              
Fair value [2],[24],[32]               (71.1)              
Investment, Identifier [Axis]: Opendoor Labs Inc, Structured Mezzanine, Real Estate 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [5],[6],[24]               88.9              
Amortized cost [5],[24]               88.9              
Fair value [2],[5],[24]               (88.9)              
Investment, Identifier [Axis]: Orchard Marine Limited, Class B Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value 0.0             $ 0.0             0.0
Investment, Identifier [Axis]: Orchard Marine Limited, Class B Common Stock, Transportation                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [6],[23],[24],[32],[42]               1,964 1,964 1,964 1,964 1,964 1,964 1,964  
Amortized cost [23],[24],[32],[42]               $ 3.1              
Fair value [2],[23],[24],[32],[42]               0.0              
Investment, Identifier [Axis]: Orchard Marine Limited, Series A Preferred Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ (64.6)             (24.6)
Investment, Identifier [Axis]: Orchard Marine Limited, Series A Preferred Stock, Transportation                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [6],[23],[24],[32],[42]               62,976 62,976 62,976 62,976 62,976 62,976 62,976  
Amortized cost [23],[24],[32],[42]               $ 62.0              
Fair value [2],[23],[24],[32],[42]               $ (64.6)              
Investment, Identifier [Axis]: Oxford Global Resources LLC, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[14],[18],[19],[40] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [13],[14],[15],[18],[19],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[14],[15],[17],[18],[19],[40] $ 94.5                            
Amortized cost [13],[14],[15],[18],[19],[40] 93.7                            
Fair value [3],[13],[14],[15],[18],[19],[40] $ (94.1)                            
Investment, Identifier [Axis]: Oxford Global Resources LLC, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 3.5                            
Amortized cost [15] 3.5                            
Fair value [3],[15] $ (3.5)                            
Investment, Identifier [Axis]: Oxford Global Resources LLC, Commercial & Professional Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 8.3                            
Amortized cost [4] 8.3                            
Fair value [3],[4] $ (8.3)                            
Investment, Identifier [Axis]: Oxford Global Resources LLC, Commercial & Professional Services 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 4.1                            
Amortized cost [4] 4.1                            
Fair value [3],[4] (4.1)                            
Investment, Identifier [Axis]: Oxford Global Resources LLC, Senior Secured Loans—First Lien, Commercial & Professional Services - 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 15.3              
Amortized cost [5]               15.3              
Fair value [2],[5]               $ (15.3)              
Investment, Identifier [Axis]: Oxford Global Resources LLC, Senior Secured Loans—First Lien, Commercial & Professional Services - 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 3.7              
Amortized cost [5]               3.7              
Fair value [2],[5]               $ (3.7)              
Investment, Identifier [Axis]: Oxford Global Resources LLC, Senior Secured Loans—First Lien, Commercial & Professional Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[9],[38],[39],[43]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [8],[9],[38],[39],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[8],[9],[38],[39],[43]               $ 88.4              
Amortized cost [8],[9],[38],[39],[43]               87.6              
Fair value [2],[8],[9],[38],[39],[43]               $ (88.2)              
Investment, Identifier [Axis]: Oxford Global Resources LLC, Senior Secured Loans—First Lien, Commercial & Professional Services -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 4.0              
Amortized cost [32]               4.0              
Fair value [2],[32]               $ (4.0)              
Investment, Identifier [Axis]: P2 Energy Solutions Inc., Senior Secured Loans—First Lien, Software & Services - 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 4.6              
Amortized cost [32]               4.3              
Fair value [2],[32]               $ (4.2)              
Investment, Identifier [Axis]: P2 Energy Solutions Inc., Senior Secured Loans—First Lien, Software & Services - 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[10],[32],[38],[39],[43]               6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%  
Base rate floor [8],[9],[10],[32],[33],[39],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[8],[9],[10],[32],[33],[39],[43]               $ 249.1              
Amortized cost [8],[9],[10],[32],[33],[39],[43]               232.7              
Fair value [2],[8],[9],[10],[32],[33],[39],[43]               $ (232.0)              
Investment, Identifier [Axis]: P2 Energy Solutions Inc., Senior Secured Loans—First Lien, Software & Services - 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 10.6              
Amortized cost [5]               10.6              
Fair value [2],[5]               (9.9)              
Investment, Identifier [Axis]: PRG III LLC, Preferred Stock, Series A PIK                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (105.7)             $ (17.4)              
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 [15],[28],[30] 434,250 [15],[28],[30] 434,250 [15],[28],[30] 434,250 [15],[28],[30] 434,250 [15],[28],[30] 434,250 [15],[28],[30] 434,250 [15],[28],[30] 434,250 [23],[31],[32] 434,250 [23],[31],[32] 434,250 [23],[31],[32] 434,250 [23],[31],[32] 434,250 [23],[31],[32] 434,250 [23],[31],[32] 434,250 [23],[31],[32]  
Amortized cost $ 18.1 [15],[28],[30]             $ 18.1 [23],[31],[32]              
Fair value (105.7) [1],[15],[28],[30]             (17.4) [2],[23],[31],[32]              
Investment, Identifier [Axis]: PRG III LLC, Preferred Stock, Series B PIK                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ 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 [15],[28],[30] 140 [15],[28],[30] 140 [15],[28],[30] 140 [15],[28],[30] 140 [15],[28],[30] 140 [15],[28],[30] 140 [15],[28],[30] 140 [23],[31],[32] 140 [23],[31],[32] 140 [23],[31],[32] 140 [23],[31],[32] 140 [23],[31],[32] 140 [23],[31],[32] 140 [23],[31],[32]  
Amortized cost $ 0.0 [15],[28],[30]             $ 0.0 [23],[31],[32]              
Fair value $ 0.0 [1],[15],[28],[30]             $ 0.0 [2],[23],[31],[32]              
Investment, Identifier [Axis]: PSKW LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [9],[10],[32],[33],[38]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [9],[10],[32],[33],[38]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[9],[10],[32],[33],[38]               $ 294.7              
Amortized cost [9],[10],[32],[33],[38]               283.5              
Fair value [2],[9],[10],[32],[33],[38]               $ (294.7)              
Investment, Identifier [Axis]: PSKW LLC (dba ConnectiveRx), Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[14],[15],[16],[19],[34] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [14],[15],[16],[19],[34] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [14],[15],[16],[17],[19],[34] $ 291.8                            
Amortized cost [14],[15],[16],[19],[34] 282.8                            
Fair value [3],[14],[15],[16],[19],[34] $ (291.8)                            
Investment, Identifier [Axis]: Pantherx Specialty LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 15.9                            
Amortized cost 14.8                            
Fair value $ (14.6)                            
Investment, Identifier [Axis]: Paradigm Acquisition Corp | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 2.5             $ 2.5              
Amortized cost 2.5             2.5              
Fair value $ (2.4)             $ (2.5)              
Investment, Identifier [Axis]: Parata Systems | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               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%  
Principal amount               $ 57.9              
Amortized cost               57.7              
Fair value               $ (58.0)              
Investment, Identifier [Axis]: Parata Systems, Senior Secured Loans—First Lien, Health Care Equipment & Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[39],[43]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [32],[39],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[39],[43]               $ 73.9              
Amortized cost [32],[39],[43]               73.4              
Fair value [2],[32],[39],[43]               $ (74.1)              
Investment, Identifier [Axis]: Parata Systems, Senior Secured Loans—First Lien, Health Care Equipment & Services -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 22.0              
Amortized cost [5]               22.0              
Fair value [2],[5]               $ (22.1)              
Investment, Identifier [Axis]: Parata Systems, Senior Secured Loans—First Lien, Health Care Equipment & Services -3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 5.5              
Amortized cost [5]               5.5              
Fair value [2],[5]               $ (5.5)              
Investment, Identifier [Axis]: Parts Town LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 49.4                            
Amortized cost 48.3                            
Fair value $ (47.8)                            
Investment, Identifier [Axis]: Parts Town LLC, Retailing 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [15],[19] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17],[19] $ 37.1                            
Amortized cost [15],[19] 36.8                            
Fair value [3],[15],[19] $ (35.9)                            
Investment, Identifier [Axis]: Parts Town LLC, Retailing 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 63.2                            
Amortized cost [15] 62.7                            
Fair value [3],[15] $ (61.1)                            
Investment, Identifier [Axis]: Parts Town LLC, Senior Secured Loans—First Lien, Retailing - 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[32]               $ 87.4              
Amortized cost [32]               86.6              
Fair value [2],[32]               $ (86.6)              
Investment, Identifier [Axis]: Parts Town LLC, Senior Secured Loans—First Lien, Retailing - 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 63.9              
Amortized cost [5]               63.9              
Fair value [2],[5]               $ (63.3)              
Investment, Identifier [Axis]: PartsSource Inc, Health Care Equipment & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 65.1                            
Amortized cost [15] 64.5                            
Fair value [3],[15] $ (62.9)                            
Investment, Identifier [Axis]: PartsSource Inc, Health Care Equipment & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 4.3                            
Amortized cost [4] 4.3                            
Fair value [3],[4] $ (4.1)                            
Investment, Identifier [Axis]: PartsSource Inc, Health Care Equipment & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 22.9                            
Amortized cost [4] 22.7                            
Fair value [3],[4] $ (22.1)                            
Investment, Identifier [Axis]: PartsSource Inc, Senior Secured Loans—First Lien, Health Care Equipment & Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[32]               $ 65.8              
Amortized cost [32]               65.0              
Fair value [2],[32]               $ (64.7)              
Investment, Identifier [Axis]: PartsSource Inc, Senior Secured Loans—First Lien, Health Care Equipment & Services -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 4.3              
Amortized cost [5]               4.2              
Fair value [2],[5]               $ (4.2)              
Investment, Identifier [Axis]: PartsSource Inc, Senior Secured Loans—First Lien, Health Care Equipment & Services -3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 22.9              
Amortized cost [5]               22.6              
Fair value [2],[5]               $ (22.5)              
Investment, Identifier [Axis]: Peraton Corp                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[36]               3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75%  
Base rate floor [32],[36]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[32],[36]               $ 9.0              
Amortized cost [32],[36]               8.7              
Fair value [2],[32],[36]               $ (9.0)              
Investment, Identifier [Axis]: Peraton Corp | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 8.8                            
Amortized cost 8.4                            
Fair value $ (8.6)                            
Investment, Identifier [Axis]: Peraton Corp 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 21.5                            
Amortized cost 21.3                            
Fair value $ (21.2)                            
Investment, Identifier [Axis]: Peraton Corp, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%                
Base rate floor [15],[34] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[34] $ 175.0                            
Amortized cost [15],[34] 166.2                            
Fair value [3],[15],[34] $ (174.7)                            
Investment, Identifier [Axis]: Peraton Corp, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 130.4                            
Amortized cost [15] 124.8                            
Fair value [3],[15] $ (128.8)                            
Investment, Identifier [Axis]: Peraton Corp, Senior Secured Loans—Second Lien, Capital Goods - 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[33]               8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%  
Base rate floor [32],[33]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[33]               $ 175.0              
Amortized cost [32],[33]               165.3              
Fair value [2],[32],[33]               $ (178.5)              
Investment, Identifier [Axis]: Peraton Corp, Senior Secured Loans—Second Lien, Capital Goods - 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               7.75% 7.75% 7.75% 7.75% 7.75% 7.75% 7.75%  
Base rate floor [32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[32]               $ 156.4              
Amortized cost [32]               149.9              
Fair value [2],[32]               $ (158.7)              
Investment, Identifier [Axis]: Performance Health Holdings Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [10],[32],[43]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [10],[32],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[10],[32],[43]               $ 120.7              
Amortized cost [10],[32],[43]               119.5              
Fair value [2],[10],[32],[43]               $ (120.2)              
Investment, Identifier [Axis]: Performance Health Holdings Inc, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[16],[18],[40] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [15],[16],[18],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[16],[17],[18],[40] $ 108.3                            
Amortized cost [15],[16],[18],[40] 107.4                            
Fair value [3],[15],[16],[18],[40] (105.4)                            
Investment, Identifier [Axis]: Petrochoice Holdings Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               8.75% 8.75% 8.75% 8.75% 8.75% 8.75% 8.75%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 65.0              
Amortized cost [32]               64.4              
Fair value [2],[32]               $ (57.6)              
Investment, Identifier [Axis]: Petroplex Acidizing Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [20],[23],[32],[42]               8.25% 8.25% 8.25% 8.25% 8.25% 8.25% 8.25%  
Interest rate, paid in kind [20],[23],[32],[42]               1.80% 1.80% 1.80% 1.80% 1.80% 1.80% 1.80%  
Base rate floor [20],[23],[32],[42]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[20],[23],[32],[42]               $ 27.0              
Amortized cost [20],[23],[32],[42]               22.0              
Fair value 0.0             $ (9.7) [2],[20],[23],[32],[42]             (4.5)
Investment, Identifier [Axis]: Petroplex Acidizing Inc | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[32],[42]               1.80% 1.80% 1.80% 1.80% 1.80% 1.80% 1.80%  
Investment, Identifier [Axis]: Petroplex Acidizing Inc, Preferred Stock A                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ 0.0             0.0
Investment, Identifier [Axis]: Petroplex Acidizing Inc, Preferred Stock A, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [23],[32],[42]               25,138,631 25,138,631 25,138,631 25,138,631 25,138,631 25,138,631 25,138,631  
Amortized cost [23],[32],[42]               $ 4.9              
Fair value [2],[23],[32],[42]               0.0              
Investment, Identifier [Axis]: Petroplex Acidizing Inc, Trade Claim, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [15],[28] 646,309 646,309 646,309 646,309 646,309 646,309 646,309                
Amortized cost [15],[28] $ 0.6                            
Fair value [1],[15],[28] (0.6)                            
Investment, Identifier [Axis]: Petroplex Acidizing Inc, Warrant                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ 0.0             0.0
Investment, Identifier [Axis]: Petroplex Acidizing Inc, Warrant, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [23],[32],[42]               8 8 8 8 8 8 8  
Amortized cost [23],[32],[42]               $ 0.0              
Fair value [2],[23],[32],[42]               $ 0.0              
Investment, Identifier [Axis]: Plaskolite, LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 1.1                            
Amortized cost 1.1                            
Fair value $ (1.0)                            
Investment, Identifier [Axis]: Polyconcept North America Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[36]               4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 4.50%  
Base rate floor [32],[36]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[36]               $ 22.8              
Amortized cost [32],[36]               22.6              
Fair value [2],[32],[36]               $ (22.7)              
Investment, Identifier [Axis]: Polyconcept North America Inc | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[36]               4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 4.50%  
Investment, Identifier [Axis]: Polyconcept North America Inc 2/16/24                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32]               11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%  
Principal amount [6],[32]               $ 10.0              
Amortized cost [32]               9.9              
Fair value [2],[32]               $ (10.0)              
Investment, Identifier [Axis]: Polyconcept North America Inc 2/16/24 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32]               11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%  
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 [15] 30,000 [15] 30,000 [15] 30,000 [15] 30,000 [15] 30,000 [15] 30,000 [15] 30,000 [23],[32] 30,000 [23],[32] 30,000 [23],[32] 30,000 [23],[32] 30,000 [23],[32] 30,000 [23],[32] 30,000 [23],[32]  
Amortized cost $ 3.0 [15]             $ 3.0 [23],[32]              
Fair value $ (10.3) [1],[15]             $ (4.3) [2],[23],[32]              
Investment, Identifier [Axis]: Precision Global Corp | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 8.9             $ 9.0              
Amortized cost 8.7             8.7              
Fair value $ (8.8)             $ (8.7)              
Investment, Identifier [Axis]: Premium Credit Ltd | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 | £                       £ 49.4      
Amortized cost               $ 63.9              
Fair value               $ (67.0)              
Investment, Identifier [Axis]: Premium Credit Ltd 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [24],[32]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base rate floor [24],[32]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | € [6],[24],[32]                     € 55.9        
Amortized cost [24],[32]               $ 72.6              
Fair value [2],[24],[32]               $ (75.7)              
Investment, Identifier [Axis]: Pretium Packaging LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 39.9             $ 39.9              
Amortized cost 39.7             39.7              
Fair value $ (31.6)             $ (39.5)              
Investment, Identifier [Axis]: Pretium Packaging LLC 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 1.6             $ 1.6              
Amortized cost 1.6             1.6              
Fair value $ (1.3)             $ (1.6)              
Investment, Identifier [Axis]: Pretium Partners LLC P1, Structured Mezzanine | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80%                
Interest rate, paid in kind 5.30% 5.30% 5.30% 5.30% 5.30% 5.30% 5.30%                
Principal amount $ 29.6                            
Amortized cost 28.6                            
Fair value $ (28.3)                            
Investment, Identifier [Axis]: Pretium Partners LLC P1, Structured Mezzanine | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 5.30% 5.30% 5.30% 5.30% 5.30% 5.30% 5.30%                
Investment, Identifier [Axis]: Pretium Partners LLC P1, Structured Mezzanine 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80%  
Interest rate, paid in kind               5.30% 5.30% 5.30% 5.30% 5.30% 5.30% 5.30%  
Investment, Identifier [Axis]: Pretium Partners LLC P1, Structured Mezzanine 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount               $ 18.9              
Amortized cost               18.6              
Fair value               $ (19.1)              
Investment, Identifier [Axis]: Pretium Partners LLC P1, Structured Mezzanine 1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind               5.30% 5.30% 5.30% 5.30% 5.30% 5.30% 5.30%  
Investment, Identifier [Axis]: Pretium Partners LLC P1, Structured Mezzanine, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [7],[24],[32]               5.30% 5.30% 5.30% 5.30% 5.30% 5.30% 5.30%  
Principal amount [6],[24],[32]               $ 6.7              
Amortized cost [24],[32]               6.2              
Fair value [2],[24],[32]               $ (6.8)              
Investment, Identifier [Axis]: Pretium Partners LLC P1, Structured Mezzanine, Real Estate | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [7],[24],[32]               5.30% 5.30% 5.30% 5.30% 5.30% 5.30% 5.30%  
Investment, Identifier [Axis]: Pretium Partners LLC P2, Private Equity | 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 $ 16.2                            
Fair value (13.7)                            
Investment, Identifier [Axis]: Pretium Partners LLC P2, Private Equity, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [6],[23],[24],[32]               16,772,368 16,772,368 16,772,368 16,772,368 16,772,368 16,772,368 16,772,368  
Amortized cost [23],[24],[32]               $ 16.4              
Fair value [2],[23],[24],[32]               (16.4)              
Investment, Identifier [Axis]: Pretium Partners LLC P2, Term Loan, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount 33.5 [15],[17],[29]             33.5 [6],[24],[32]              
Amortized cost 33.0 [15],[29]             32.9 [24],[32]              
Fair value $ (32.9) [3],[15],[29]             $ (32.9) [2],[24],[32]              
Investment, Identifier [Axis]: Prime ST LLC, Private Equity, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 5,666,079 [15],[28],[29],[30] 5,666,079 [15],[28],[29],[30] 5,666,079 [15],[28],[29],[30] 5,666,079 [15],[28],[29],[30] 5,666,079 [15],[28],[29],[30] 5,666,079 [15],[28],[29],[30] 5,666,079 [15],[28],[29],[30] 5,983,135 [6],[23],[24],[31],[32] 5,983,135 [6],[23],[24],[31],[32] 5,983,135 [6],[23],[24],[31],[32] 5,983,135 [6],[23],[24],[31],[32] 5,983,135 [6],[23],[24],[31],[32] 5,983,135 [6],[23],[24],[31],[32] 5,983,135 [6],[23],[24],[31],[32]  
Amortized cost $ 7.4 [15],[28],[29],[30]             $ 7.7 [23],[24],[31],[32]              
Fair value $ 0.0 [3],[15],[28],[29],[30]             $ (9.1) [2],[23],[24],[31],[32]              
Investment, Identifier [Axis]: Prime ST LLC, Structured Mezzanine, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 6.00% [12],[15],[29],[30] 6.00% [12],[15],[29],[30] 6.00% [12],[15],[29],[30] 6.00% [12],[15],[29],[30] 6.00% [12],[15],[29],[30] 6.00% [12],[15],[29],[30] 6.00% [12],[15],[29],[30] 6.00% [7],[24],[31],[32] 6.00% [7],[24],[31],[32] 6.00% [7],[24],[31],[32] 6.00% [7],[24],[31],[32] 6.00% [7],[24],[31],[32] 6.00% [7],[24],[31],[32] 6.00% [7],[24],[31],[32]  
Principal amount $ 55.5 [15],[17],[29],[30]             $ 52.4 [6],[24],[31],[32]              
Amortized cost 53.7 [15],[29],[30]             50.4 [24],[31],[32]              
Fair value $ (43.5) [3],[15],[29],[30]             $ (52.4) [2],[24],[31],[32]              
Investment, Identifier [Axis]: Prime ST LLC, Structured Mezzanine, Real Estate | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 6.00% [12],[15],[29],[30] 6.00% [12],[15],[29],[30] 6.00% [12],[15],[29],[30] 6.00% [12],[15],[29],[30] 6.00% [12],[15],[29],[30] 6.00% [12],[15],[29],[30] 6.00% [12],[15],[29],[30] 6.00% [7],[24],[31],[32] 6.00% [7],[24],[31],[32] 6.00% [7],[24],[31],[32] 6.00% [7],[24],[31],[32] 6.00% [7],[24],[31],[32] 6.00% [7],[24],[31],[32] 6.00% [7],[24],[31],[32]  
Investment, Identifier [Axis]: Prime St LLC, Private Equity                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ (9.1)             (3.9)
Investment, Identifier [Axis]: Prime St LLC, Structured Mezzanine                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value (43.5)             (52.4)             (22.8)
Investment, Identifier [Axis]: Production Resource Group LLC 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value (152.5)             (133.3)             0.0
Investment, Identifier [Axis]: Production Resource Group LLC 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value (0.1)             (0.1)             0.0
Investment, Identifier [Axis]: Production Resource Group LLC 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value (68.1)             (64.4)             0.0
Investment, Identifier [Axis]: Production Resource Group LLC 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (31.3)             (20.2)             0.0
Investment, Identifier [Axis]: Production Resource Group LLC, Media & Entertainment 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[30] 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%                
Interest rate, paid in kind [12],[15],[30] 3.10% 3.10% 3.10% 3.10% 3.10% 3.10% 3.10%                
Base rate floor [15],[30] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[30] $ 62.7                            
Amortized cost [15],[30] 59.9                            
Fair value [3],[15],[30] $ (64.6)                            
Investment, Identifier [Axis]: Production Resource Group LLC, Media & Entertainment 1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15],[30] 3.10% 3.10% 3.10% 3.10% 3.10% 3.10% 3.10%                
Investment, Identifier [Axis]: Production Resource Group LLC, Media & Entertainment 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[30] 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00%                
Interest rate, paid in kind [12],[15],[30] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [15],[30] 0.30% 0.30% 0.30% 0.30% 0.30% 0.30% 0.30%                
Principal amount [15],[17],[30] $ 149.6                            
Amortized cost [15],[30] 143.9                            
Fair value [3],[15],[30] $ (152.5)                            
Investment, Identifier [Axis]: Production Resource Group LLC, Media & Entertainment 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15],[30] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Investment, Identifier [Axis]: Production Resource Group LLC, Media & Entertainment 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[30] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [15],[30] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[30] $ 0.1                            
Amortized cost [15],[30] 0.1                            
Fair value [3],[15],[30] $ (0.1)                            
Investment, Identifier [Axis]: Production Resource Group LLC, Media & Entertainment 3 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[30] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Investment, Identifier [Axis]: Production Resource Group LLC, Media & Entertainment 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[30] 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%                
Interest rate, paid in kind [12],[15],[30] 3.10% 3.10% 3.10% 3.10% 3.10% 3.10% 3.10%                
Base rate floor [15],[30] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[30] $ 34.4                            
Amortized cost [15],[30] 34.3                            
Fair value [3],[15],[30] $ (34.8)                            
Investment, Identifier [Axis]: Production Resource Group LLC, Media & Entertainment 4 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15],[30] 3.10% 3.10% 3.10% 3.10% 3.10% 3.10% 3.10%                
Investment, Identifier [Axis]: Production Resource Group LLC, Preferred Stock, Series A PIK                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               (17.4)             0.0
Investment, Identifier [Axis]: Production Resource Group LLC, Preferred Stock, Series B PIK                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               $ 0.0             0.0
Investment, Identifier [Axis]: Production Resource Group LLC, Senior Secured Loans—First Lien, Media & Entertainment -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [31],[32]               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Interest rate, paid in kind [31],[32]               3.10% 3.10% 3.10% 3.10% 3.10% 3.10% 3.10%  
Base rate floor [31],[32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[31],[32]               $ 64.4              
Amortized cost [31],[32]               60.2              
Fair value [2],[31],[32]               $ (64.4)              
Investment, Identifier [Axis]: Production Resource Group LLC, Senior Secured Loans—First Lien, Media & Entertainment -1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [31],[32]               3.10% 3.10% 3.10% 3.10% 3.10% 3.10% 3.10%  
Investment, Identifier [Axis]: Production Resource Group LLC, Senior Secured Loans—First Lien, Media & Entertainment -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [31],[32]               3.00% 3.00% 3.00% 3.00% 3.00% 3.00% 3.00%  
Interest rate, paid in kind [31],[32]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [31],[32]               0.30% 0.30% 0.30% 0.30% 0.30% 0.30% 0.30%  
Principal amount [6],[31],[32]               $ 133.3              
Amortized cost [31],[32]               124.9              
Fair value [2],[31],[32]               $ (133.3)              
Investment, Identifier [Axis]: Production Resource Group LLC, Senior Secured Loans—First Lien, Media & Entertainment -2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [31],[32]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Investment, Identifier [Axis]: Production Resource Group LLC, Senior Secured Loans—First Lien, Media & Entertainment -3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [31],[32]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [31],[32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[31],[32]               $ 0.1              
Amortized cost [31],[32]               0.1              
Fair value [2],[31],[32]               $ (0.1)              
Investment, Identifier [Axis]: Production Resource Group LLC, Senior Secured Loans—First Lien, Media & Entertainment -3 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [31],[32]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Investment, Identifier [Axis]: Production Resource Group LLC, Senior Secured Loans—First Lien, Media & Entertainment -4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [31],[32]               7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%  
Interest rate, paid in kind [31],[32]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base rate floor [31],[32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[31],[32]               $ 20.2              
Amortized cost [31],[32]               20.1              
Fair value [2],[31],[32]               $ (20.2)              
Investment, Identifier [Axis]: Production Resource Group LLC, Senior Secured Loans—First Lien, Media & Entertainment -4 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [31],[32]               3.10% 3.10% 3.10% 3.10% 3.10% 3.10% 3.10%  
Investment, Identifier [Axis]: Production Resource Group LLC, Senior Secured Loans—First Lien, Media & Entertainment -5                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5],[31]               7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%  
Interest rate, paid in kind [5],[31]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base rate floor [5],[31]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6],[31]               $ 10.1              
Amortized cost [5],[31]               10.1              
Fair value [2],[5],[31]               $ (10.1)              
Investment, Identifier [Axis]: Production Resource Group LLC, Senior Secured Loans—First Lien, Media & Entertainment -5 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [5],[31]               3.10% 3.10% 3.10% 3.10% 3.10% 3.10% 3.10%  
Investment, Identifier [Axis]: Project Marron 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount           $ 81.8                  
Amortized cost $ 56.4                            
Fair value $ (52.0)                            
Investment, Identifier [Axis]: Project Marron 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount             $ 52.5                
Amortized cost $ 40.1                            
Fair value (36.3)                            
Investment, Identifier [Axis]: Project Marron B+575 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               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%  
Principal amount                         $ 3.2    
Amortized cost               $ 2.3              
Fair value               $ (2.2)              
Investment, Identifier [Axis]: Project Marron B+625 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               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%  
Principal amount                         $ 63.6    
Amortized cost               $ 43.9              
Fair value               $ (43.6)              
Investment, Identifier [Axis]: Project Marron C+625 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               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%  
Principal amount                           $ 52.5  
Amortized cost               $ 39.9              
Fair value               $ (39.1)              
Investment, Identifier [Axis]: Propulsion Acquisition LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [9],[32],[33],[38],[43]               7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%  
Base rate floor [9],[32],[33],[38],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[9],[32],[33],[38],[43]               $ 60.5              
Amortized cost [9],[32],[33],[38],[43]               56.8              
Fair value [2],[9],[32],[33],[38],[43]               (61.1)              
Investment, Identifier [Axis]: Proserv Acquisition LLC, Class A Common Units                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (1.1)             $ (0.1)             (9.0)
Investment, Identifier [Axis]: Proserv Acquisition LLC, Class A Common Units, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 2,635,005 [15],[28],[29],[41] 2,635,005 [15],[28],[29],[41] 2,635,005 [15],[28],[29],[41] 2,635,005 [15],[28],[29],[41] 2,635,005 [15],[28],[29],[41] 2,635,005 [15],[28],[29],[41] 2,635,005 [15],[28],[29],[41] 2,635,005 [23],[24],[32],[42] 2,635,005 [23],[24],[32],[42] 2,635,005 [23],[24],[32],[42] 2,635,005 [23],[24],[32],[42] 2,635,005 [23],[24],[32],[42] 2,635,005 [23],[24],[32],[42] 2,635,005 [23],[24],[32],[42]  
Amortized cost $ 33.5 [15],[28],[29],[41]             $ 33.4 [23],[24],[32],[42]              
Fair value (1.1) [1],[15],[28],[29],[41]             (0.1) [2],[23],[24],[32],[42]              
Investment, Identifier [Axis]: Proserv Acquisition LLC, Class A Preferred Units                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (9.5)             $ (9.3)             (9.5)
Investment, Identifier [Axis]: Proserv Acquisition LLC, Class A Preferred Units, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 837,780 [15],[28],[29],[41] 837,780 [15],[28],[29],[41] 837,780 [15],[28],[29],[41] 837,780 [15],[28],[29],[41] 837,780 [15],[28],[29],[41] 837,780 [15],[28],[29],[41] 837,780 [15],[28],[29],[41] 837,780 [23],[24],[32],[42] 837,780 [23],[24],[32],[42] 837,780 [23],[24],[32],[42] 837,780 [23],[24],[32],[42] 837,780 [23],[24],[32],[42] 837,780 [23],[24],[32],[42] 837,780 [23],[24],[32],[42]  
Amortized cost $ 5.4 [15],[28],[29],[41]             $ 5.4 [23],[24],[32],[42]              
Fair value $ (9.5) [1],[15],[28],[29],[41]             $ (9.3) [2],[23],[24],[32],[42]              
Investment, Identifier [Axis]: Pure Fishing Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 9.8                            
Amortized cost 9.7                            
Fair value $ (6.6)                            
Investment, Identifier [Axis]: Pure Fishing Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               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%  
Principal amount               $ 9.9              
Amortized cost               9.8              
Fair value               $ (9.6)              
Investment, Identifier [Axis]: Pure Fishing Inc 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[39],[43]               8.38% 8.38% 8.38% 8.38% 8.38% 8.38% 8.38%  
Base rate floor [32],[39],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[39],[43]               $ 177.0              
Amortized cost [32],[39],[43]               170.6              
Fair value [2],[32],[39],[43]               $ (168.1)              
Investment, Identifier [Axis]: Pure Fishing Inc 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 26.5             $ 46.8              
Amortized cost 24.2             42.0              
Fair value $ (14.8)             $ (44.5)              
Investment, Identifier [Axis]: Pure Fishing Inc, Consumer Durables & Apparel 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[37] 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 4.50%                
Base rate floor [15],[37] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount [15],[17],[37] $ 33.7                            
Amortized cost [15],[37] 33.2                            
Fair value [3],[15],[37] $ (22.6)                            
Investment, Identifier [Axis]: Pure Fishing Inc, Consumer Durables & Apparel 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 8.38% 8.38% 8.38% 8.38% 8.38% 8.38% 8.38%                
Base rate floor [15],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[40] $ 100.0                            
Amortized cost [15],[40] 95.3                            
Fair value [3],[15],[40] $ (56.1)                            
Investment, Identifier [Axis]: Pure Gym Ltd, Private Equity | 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                
Amortized cost $ 39.4                            
Fair value $ (39.2)                            
Investment, Identifier [Axis]: Qdoba Restaurant Corp                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[36],[39]               7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%  
Base rate floor [32],[36],[39]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[36],[39]               $ 10.9              
Amortized cost [32],[36],[39]               10.8              
Fair value [2],[32],[36],[39]               $ (10.8)              
Investment, Identifier [Axis]: Qdoba Restaurant Corp 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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               $ 3.5              
Amortized cost               3.3              
Fair value               $ (3.4)              
Investment, Identifier [Axis]: Quorum Health Corp, Trade Claim, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 8,301,000 [15],[28] 8,301,000 [15],[28] 8,301,000 [15],[28] 8,301,000 [15],[28] 8,301,000 [15],[28] 8,301,000 [15],[28] 8,301,000 [15],[28] 8,301,000 [23],[32] 8,301,000 [23],[32] 8,301,000 [23],[32] 8,301,000 [23],[32] 8,301,000 [23],[32] 8,301,000 [23],[32] 8,301,000 [23],[32]  
Amortized cost $ 0.7 [15],[28]             $ 0.7 [23],[32]              
Fair value $ (0.9) [1],[15],[28]             $ (0.9) [2],[23],[32]              
Investment, Identifier [Axis]: Quorum Health Corp, Trust Initial Funding Units, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 143,400 [15],[28] 143,400 [15],[28] 143,400 [15],[28] 143,400 [15],[28] 143,400 [15],[28] 143,400 [15],[28] 143,400 [15],[28] 143,400 [23],[32] 143,400 [23],[32] 143,400 [23],[32] 143,400 [23],[32] 143,400 [23],[32] 143,400 [23],[32] 143,400 [23],[32]  
Amortized cost $ 0.2 [15],[28]             $ 0.2 [23],[32]              
Fair value $ (0.2) [1],[15],[28]             $ (0.2) [2],[23],[32]              
Investment, Identifier [Axis]: RSC Insurance Brokerage Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 18.8             $ 19.0              
Amortized cost 18.8             19.0              
Fair value $ (18.5)             $ (19.2)              
Investment, Identifier [Axis]: RSC Insurance Brokerage Inc, Senior Secured Loans—First Lien, Insurance -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[9],[10],[32],[33],[39],[43]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [8],[9],[10],[32],[33],[39],[43]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[8],[9],[10],[32],[33],[39],[43]               $ 277.8              
Amortized cost [8],[9],[10],[32],[33],[39],[43]               268.1              
Fair value [2],[8],[9],[10],[32],[33],[39],[43]               $ (280.6)              
Investment, Identifier [Axis]: RSC Insurance Brokerage Inc, Senior Secured Loans—First Lien, Insurance -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[32]               $ 4.1              
Amortized cost [32]               4.0              
Fair value [2],[32]               $ (4.1)              
Investment, Identifier [Axis]: RSC Insurance Brokerage Inc, Senior Secured Loans—First Lien, Insurance -3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 16.1              
Amortized cost [5]               16.1              
Fair value [2],[5]               $ (16.3)              
Investment, Identifier [Axis]: RSC Insurance Brokerage Inc, Senior Secured Loans—First Lien, Insurance -4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 3.6              
Amortized cost [5]               3.6              
Fair value [2],[5]               $ (3.6)              
Investment, Identifier [Axis]: RSC Insurance Brokerage Inc, Insurance 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[14],[15],[16],[34],[40] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [13],[14],[15],[16],[34],[40] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[14],[15],[16],[17],[34],[40] $ 240.0                            
Amortized cost [13],[14],[15],[16],[34],[40] 234.3                            
Fair value [3],[13],[14],[15],[16],[34],[40] $ (236.0)                            
Investment, Identifier [Axis]: RSC Insurance Brokerage Inc, Insurance 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 7.7                            
Amortized cost [4] 7.6                            
Fair value [3],[4] $ (7.6)                            
Investment, Identifier [Axis]: Radwell International LLC/PA, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 6.53% 6.53% 6.53% 6.53% 6.53% 6.53% 6.53%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 1.0                            
Amortized cost [15] 1.0                            
Fair value [3],[15] $ (1.0)                            
Investment, Identifier [Axis]: Radwell International LLC/PA, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%                
Base rate floor [13],[14],[16],[19] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[14],[16],[17],[19] $ 92.1                            
Amortized cost [13],[14],[16],[19] 92.1                            
Fair value [3],[13],[14],[16],[19] $ (92.1)                            
Investment, Identifier [Axis]: Radwell International LLC/PA, Capital Goods 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 6.9                            
Amortized cost [4] 6.9                            
Fair value [3],[4] $ (6.9)                            
Investment, Identifier [Axis]: Reliant Rehab Hospital Cincinnati LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [9],[10],[32],[33],[39],[43]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [9],[10],[32],[33],[39],[43]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount [6],[9],[10],[32],[33],[39],[43]               $ 126.8              
Amortized cost [9],[10],[32],[33],[39],[43]               120.7              
Fair value [2],[9],[10],[32],[33],[39],[43]               $ (124.1)              
Investment, Identifier [Axis]: Reliant Rehab Hospital Cincinnati LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 33.6                            
Amortized cost 32.7                            
Fair value $ (26.7)                            
Investment, Identifier [Axis]: Reliant Rehab Hospital Cincinnati LLC 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               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%  
Principal amount               $ 15.6              
Amortized cost               15.2              
Fair value               $ (15.3)              
Investment, Identifier [Axis]: Reliant Rehab Hospital Cincinnati LLC, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[14],[15],[16],[18],[34],[40] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [14],[15],[16],[18],[34],[40] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount [14],[15],[16],[17],[18],[34],[40] $ 106.1                            
Amortized cost [14],[15],[16],[18],[34],[40] 101.1                            
Fair value [3],[14],[15],[16],[18],[34],[40] $ (84.2)                            
Investment, Identifier [Axis]: Revere Superior Holdings Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 19.6             $ 19.8              
Amortized cost 19.6             19.8              
Fair value $ (19.6)             $ (19.9)              
Investment, Identifier [Axis]: Revere Superior Holdings Inc, Senior Secured Loans—First Lien, Software & Services - 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[39]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [32],[39]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[39]               $ 23.0              
Amortized cost [32],[39]               22.4              
Fair value [2],[32],[39]               $ (23.3)              
Investment, Identifier [Axis]: Revere Superior Holdings Inc, Senior Secured Loans—First Lien, Software & Services - 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 3.3              
Amortized cost [32]               3.3              
Fair value [2],[32]               $ (3.4)              
Investment, Identifier [Axis]: Revere Superior Holdings Inc, Senior Secured Loans—First Lien, Software & Services - 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 3.2              
Amortized cost [5]               3.2              
Fair value [2],[5]               $ (3.2)              
Investment, Identifier [Axis]: Revere Superior Holdings Inc, Senior Secured Loans—First Lien, Software & Services - 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 7.4              
Amortized cost [5]               7.4              
Fair value [2],[5]               $ (7.5)              
Investment, Identifier [Axis]: Revere Superior Holdings Inc, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15],[40] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [15],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[40] $ 33.5                            
Amortized cost [15],[40] 32.9                            
Fair value [3],[15],[40] $ (33.5)                            
Investment, Identifier [Axis]: Revere Superior Holdings Inc, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 1.5                            
Amortized cost [15] 1.5                            
Fair value [3],[15] $ (1.5)                            
Investment, Identifier [Axis]: Revere Superior Holdings Inc, Software & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 1.7                            
Amortized cost [4] 1.7                            
Fair value [3],[4] $ (1.7)                            
Investment, Identifier [Axis]: Ridgeback Resources Inc, Common Stock, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 1,969,418 [15],[29],[53],[54] 1,969,418 [15],[29],[53],[54] 1,969,418 [15],[29],[53],[54] 1,969,418 [15],[29],[53],[54] 1,969,418 [15],[29],[53],[54] 1,969,418 [15],[29],[53],[54] 1,969,418 [15],[29],[53],[54] 1,969,418 [11],[23],[24],[32],[52] 1,969,418 [11],[23],[24],[32],[52] 1,969,418 [11],[23],[24],[32],[52] 1,969,418 [11],[23],[24],[32],[52] 1,969,418 [11],[23],[24],[32],[52] 1,969,418 [11],[23],[24],[32],[52] 1,969,418 [11],[23],[24],[32],[52]  
Amortized cost $ 6.4 [15],[29],[53],[54]             $ 9.1 [11],[23],[24],[32],[52]              
Fair value $ (8.6) [1],[15],[29],[53],[54]             $ (9.9) [2],[11],[23],[24],[32],[52]              
Investment, Identifier [Axis]: Rise Baking Company 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 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 $ 0.5             $ 1.0              
Amortized cost 0.5             1.0              
Fair value $ (0.5)             $ (1.0)              
Investment, Identifier [Axis]: Rise Baking Company 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 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 $ 30.4             $ 30.7              
Amortized cost 29.8             30.0              
Fair value $ (29.2)             $ (30.1)              
Investment, Identifier [Axis]: Rise Baking Company 3 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 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 $ 1.4             $ 0.9              
Amortized cost 1.4             0.9              
Fair value $ (1.4)             $ (0.9)              
Investment, Identifier [Axis]: Rise Baking Company, Senior Secured Loans—First Lien, Food, Beverage & Tobacco -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 2.8              
Amortized cost [32]               2.6              
Fair value [2],[32]               $ (2.7)              
Investment, Identifier [Axis]: Rise Baking Company, Senior Secured Loans—First Lien, Food, Beverage & Tobacco -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [9],[39]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [9],[39]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[9],[39]               $ 28.8              
Amortized cost [9],[39]               28.1              
Fair value [2],[9],[39]               $ (28.2)              
Investment, Identifier [Axis]: Rise Baking Company, Senior Secured Loans—First Lien, Food, Beverage & Tobacco -3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 2.5              
Amortized cost [5]               2.5              
Fair value [2],[5]               (2.5)              
Investment, Identifier [Axis]: Rise Baking Company, Food, Beverage & Tobacco 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 1.4                            
Amortized cost [15] 1.3                            
Fair value [3],[15] $ (1.3)                            
Investment, Identifier [Axis]: Rise Baking Company, Food, Beverage & Tobacco 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[14],[40] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [14],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [14],[17],[40] $ 28.5                            
Amortized cost [14],[40] 28.0                            
Fair value [3],[14],[40] $ (27.4)                            
Investment, Identifier [Axis]: Rise Baking Company, Food, Beverage & Tobacco 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 3.9                            
Amortized cost [4] 3.9                            
Fair value [3],[4] (3.7)                            
Investment, Identifier [Axis]: Roemanu LLC (FKA Toorak Capital Partners LLC), Private Equity                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (261.2)             (199.3)              
Investment, Identifier [Axis]: Roemanu LLC (FKA Toorak Capital Partners LLC), Private Equity | 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 $ 50.2                            
Fair value $ (47.3)                            
Investment, Identifier [Axis]: Roemanu LLC (FKA Toorak Capital Partners LLC), Private Equity, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [15],[30] 220,778,388 220,778,388 220,778,388 220,778,388 220,778,388 220,778,388 220,778,388                
Amortized cost [15],[30] $ 236.4                            
Fair value [3],[15],[30] (261.2)                            
Investment, Identifier [Axis]: Roemanu LLC (FKA Toorak Capital Partners LLC), Structured Mezzanine                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ (22.0)              
Investment, Identifier [Axis]: SAMBA Safety Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 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 $ 27.1             $ 27.4              
Amortized cost 26.9             27.1              
Fair value $ (26.8)             $ (27.2)              
Investment, Identifier [Axis]: SAMBA Safety Inc, Senior Secured Loans—First Lien, Software & Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 2.4              
Amortized cost [5]               2.4              
Fair value [2],[5]               $ (2.4)              
Investment, Identifier [Axis]: SAMBA Safety Inc, Senior Secured Loans—First Lien, Software & Services -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 6.1              
Amortized cost [5]               6.1              
Fair value [2],[5]               $ (6.0)              
Investment, Identifier [Axis]: SAMBA Safety Inc, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%                
Base rate floor [40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [17],[40] $ 6.1                            
Amortized cost [40] 6.0                            
Fair value [3],[40] $ (6.0)                            
Investment, Identifier [Axis]: SAMBA Safety Inc, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 2.4                            
Amortized cost [4] 2.4                            
Fair value [3],[4] $ (2.4)                            
Investment, Identifier [Axis]: SG Residential Mortgage Trust 2022-2, Structured Mezzanine | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Base rate floor 5.40% 5.40% 5.40% 5.40% 5.40% 5.40% 5.40%                
Principal amount $ 4.6                            
Amortized cost 3.8                            
Fair value $ (3.7)                            
Investment, Identifier [Axis]: SI Group Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 1.5                            
Amortized cost 1.5                            
Fair value $ (1.2)                            
Investment, Identifier [Axis]: SIRVA Worldwide Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[36]               9.50% 9.50% 9.50% 9.50% 9.50% 9.50% 9.50%  
Base rate floor [32],[36]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount [6],[32],[36]               $ 6.5              
Amortized cost [32],[36]               5.4              
Fair value [2],[32],[36]               $ (5.7)              
Investment, Identifier [Axis]: SIRVA Worldwide Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 10.3                            
Amortized cost 8.7                            
Fair value $ (8.9)                            
Investment, Identifier [Axis]: SIRVA Worldwide Inc 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 6.9             $ 7.1              
Amortized cost 6.6             6.7              
Fair value $ (6.1)             $ (6.4)              
Investment, Identifier [Axis]: SIRVA Worldwide Inc 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               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%  
Principal amount               $ 3.8              
Amortized cost               3.1              
Fair value               $ (3.3)              
Investment, Identifier [Axis]: Safe-Guard Products International LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [38],[39],[43]               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Base rate floor [38],[39],[43]               0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Principal amount [6],[38],[39],[43]               $ 45.1              
Amortized cost [38],[39],[43]               42.5              
Fair value [2],[38],[39],[43]               $ (45.1)              
Investment, Identifier [Axis]: Safe-Guard Products International LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 71.7                            
Amortized cost 72.1                            
Fair value $ (71.7)                            
Investment, Identifier [Axis]: Safe-Guard Products International LLC 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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               $ 75.5              
Amortized cost               76.0              
Fair value               $ (75.5)              
Investment, Identifier [Axis]: Safe-Guard Products International LLC, Diversified Financials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[18] 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%                
Base rate floor [18] 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount [17],[18] $ 0.1                            
Amortized cost [18] 0.1                            
Fair value [3],[18] (0.1)                            
Investment, Identifier [Axis]: Saluda Grade Alternative Mortgage Trust 2022-BC2, Structured Mezzanine, Real Estate 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [15],[17],[29] 5.7                            
Amortized cost [15],[29] 5.7                            
Fair value [3],[15],[29] (5.7)                            
Investment, Identifier [Axis]: Saluda Grade Alternative Mortgage Trust 2022-BC2, Structured Mezzanine, Real Estate 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [15],[17],[29] 3.4                            
Amortized cost [15],[29] 2.3                            
Fair value [3],[15],[29] $ (2.4)                            
Investment, Identifier [Axis]: Saluda Grade Alternative Mortgage Trust 2022-BC2, Term Loan | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 7.30% 7.30% 7.30% 7.30% 7.30% 7.30% 7.30%                
Principal amount $ 24.0                            
Amortized cost 23.7                            
Fair value (23.7)                            
Investment, Identifier [Axis]: Saluda Grade Alternative Mortgage Trust 2022-BC2, Term Loan, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [15],[17],[29] 10.5                            
Amortized cost [15],[29] 10.5                            
Fair value [3],[15],[29] $ (10.3)                            
Investment, Identifier [Axis]: SavATree LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 39.6             $ 40.0              
Amortized cost 39.2             39.7              
Fair value $ (38.9)             $ (39.7)              
Investment, Identifier [Axis]: SavATree LLC, Senior Secured Loans—First Lien, Consumer Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[32]               $ 1.9              
Amortized cost [32]               1.8              
Fair value [2],[32]               $ (1.9)              
Investment, Identifier [Axis]: SavATree LLC, Senior Secured Loans—First Lien, Consumer Services -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 7.6              
Amortized cost [5]               7.6              
Fair value [2],[5]               $ (7.6)              
Investment, Identifier [Axis]: SavATree LLC, Senior Secured Loans—First Lien, Consumer Services -3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 6.3              
Amortized cost [5]               6.3              
Fair value [2],[5]               $ (6.3)              
Investment, Identifier [Axis]: SavATree LLC, Consumer Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[15] 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 5.5                            
Amortized cost [15] 5.5                            
Fair value [3],[15] $ (5.4)                            
Investment, Identifier [Axis]: SavATree LLC, Consumer Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 4.0                            
Amortized cost [4] 4.0                            
Fair value [3],[4] $ (3.9)                            
Investment, Identifier [Axis]: SavATree LLC, Consumer Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [4],[12] 5.25% 5.25% 5.25% 5.25% 5.25% 5.25% 5.25%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 6.3                            
Amortized cost [4] 6.3                            
Fair value [3],[4] $ (6.2)                            
Investment, Identifier [Axis]: Sealane Trade Finance | 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                
Amortized cost $ 1.1                            
Fair value $ (0.2)                            
Investment, Identifier [Axis]: Sealane Trade Finance L+375                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75%  
Investment, Identifier [Axis]: Sealane Trade Finance L+375 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Base rate floor               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount               $ 5.0              
Amortized cost               5.0              
Fair value               $ (5.0)              
Investment, Identifier [Axis]: Sealane Trade Finance L+963                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               9.63% 9.63% 9.63% 9.63% 9.63% 9.63% 9.63%  
Investment, Identifier [Axis]: Sealane Trade Finance L+963 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Base rate floor               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount               $ 11.2              
Amortized cost               11.2              
Fair value               $ (11.2)              
Investment, Identifier [Axis]: Sequa Corp                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[36],[39]               10.75% 10.75% 10.75% 10.75% 10.75% 10.75% 10.75%  
Interest rate, paid in kind [32],[36],[39]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base rate floor [32],[36],[39]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[36],[39]               $ 5.9              
Amortized cost [32],[36],[39]               5.7              
Fair value [2],[32],[36],[39]               $ (5.9)              
Investment, Identifier [Axis]: Sequa Corp | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32],[36],[39]               6.80% 6.80% 6.80% 6.80% 6.80% 6.80% 6.80%  
Investment, Identifier [Axis]: Sequa Corp 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               10.75% 10.75% 10.75% 10.75% 10.75% 10.75% 10.75%  
Interest rate, paid in kind               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%  
Principal amount               $ 39.1              
Amortized cost               33.9              
Fair value               $ (39.1)              
Investment, Identifier [Axis]: Sequa Corp 1 | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind               6.80% 6.80% 6.80% 6.80% 6.80% 6.80% 6.80%  
Investment, Identifier [Axis]: Sequa Corp 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%  
Interest rate, paid in kind               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%  
Principal amount               $ 45.4              
Amortized cost               43.9              
Fair value               $ (45.8)              
Investment, Identifier [Axis]: Sequa Corp 2 | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Investment, Identifier [Axis]: Sequa Corp, Fair Value Hierarchy, Senior Secured Loans—First Lien, Capital Goods -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[36],[39]               6.75% 6.75% 6.75% 6.75% 6.75% 6.75% 6.75%  
Interest rate, paid in kind [32],[36],[39]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base rate floor [32],[36],[39]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[36],[39]               $ 16.0              
Amortized cost [32],[36],[39]               15.4              
Fair value [2],[32],[36],[39]               $ (16.2)              
Investment, Identifier [Axis]: Sequa Corp, Fair Value Hierarchy, Senior Secured Loans—First Lien, Capital Goods -1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32],[36],[39]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Investment, Identifier [Axis]: Sequa Corp, Fair Value Hierarchy, Senior Secured Loans—First Lien, Capital Goods -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%  
Interest rate, paid in kind [32]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 16.4              
Amortized cost [32]               16.0              
Fair value [2],[32]               $ (17.2)              
Investment, Identifier [Axis]: Sequa Corp, Fair Value Hierarchy, Senior Secured Loans—First Lien, Capital Goods -2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32]               9.50% 9.50% 9.50% 9.50% 9.50% 9.50% 9.50%  
Investment, Identifier [Axis]: Sequel Youth & Family Services LLC, Senior Secured Loans—First Lien, Health Care Equipment & Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [20],[23],[32]               8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%  
Base rate floor [20],[23],[32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[20],[23],[32]               $ 170.0              
Amortized cost [20],[23],[32]               106.4              
Fair value [2],[20],[23],[32]               $ (51.6)              
Investment, Identifier [Axis]: Sequel Youth & Family Services LLC, Senior Secured Loans—First Lien, Health Care Equipment & Services -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [20],[23],[32]               7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%  
Base rate floor [20],[23],[32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[20],[23],[32]               $ 29.2              
Amortized cost [20],[23],[32]               19.3              
Fair value [2],[20],[23],[32]               $ (8.9)              
Investment, Identifier [Axis]: Sequel Youth & Family Services LLC, Senior Secured Loans—First Lien, Health Care Equipment & Services -3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 36.0              
Amortized cost [32]               36.0              
Fair value [2],[32]               $ (36.0)              
Investment, Identifier [Axis]: Sequel Youth & Family Services LLC, Senior Secured Loans—First Lien, Health Care Equipment & Services -4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 6.0              
Amortized cost [5]               6.0              
Fair value [2],[5]               $ (6.0)              
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 [28],[51] 900,000 900,000 900,000 900,000 900,000 900,000 900,000                
Amortized cost [28],[51] $ 0.0                            
Fair value [1],[28],[51] 0.0                            
Investment, Identifier [Axis]: Sequel Youth & Family Services LLC, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [15],[17],[25],[28] 57.2                            
Amortized cost [15],[25],[28] 8.9                            
Fair value [3],[15],[25],[28] $ (0.3)                            
Investment, Identifier [Axis]: SitusAMC Holdings Corp                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[9],[32]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [8],[9],[32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[8],[9],[32]               $ 95.4              
Amortized cost [8],[9],[32]               94.5              
Fair value [2],[8],[9],[32]               $ (94.4)              
Investment, Identifier [Axis]: SitusAMC Holdings Corp | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 39.5                            
Amortized cost 38.7                            
Fair value $ (38.1)                            
Investment, Identifier [Axis]: SitusAMC Holdings Corp, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[14],[15] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [13],[14],[19] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[14],[17],[19] $ 55.2                            
Amortized cost [13],[14],[19] 54.7                            
Fair value [3],[13],[14],[19] $ (53.2)                            
Investment, Identifier [Axis]: Solera LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[36]               8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%  
Base rate floor [32],[36]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[36]               $ 312.4              
Amortized cost [32],[36]               295.8              
Fair value [2],[32],[36]               $ (317.6)              
Investment, Identifier [Axis]: Solera LLC, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%                
Base rate floor [15],[37] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[37] $ 312.4                            
Amortized cost [15],[37] 297.3                            
Fair value [3],[15],[37] $ (307.7)                            
Investment, Identifier [Axis]: Solina France SASU, Food, Beverage & Tobacco                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [15],[29],[40] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount [15],[17],[29],[40] $ 40.0                            
Amortized cost [15],[29],[40] 38.8                            
Fair value [3],[15],[29],[40] (39.1)                            
Investment, Identifier [Axis]: Sorenson Communications LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[32],[36],[38],[42],[43]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [8],[32],[36],[38],[42],[43]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[8],[32],[36],[38],[42],[43]               $ 59.9              
Amortized cost [8],[32],[36],[38],[42],[43]               56.9              
Fair value [61] $ 0.0             (60.1) [2],[8],[32],[36],[38],[42],[43]              
Investment, Identifier [Axis]: Sorenson Communications LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 20.0                            
Amortized cost 19.3                            
Fair value (19.1)                            
Investment, Identifier [Axis]: Sorenson Communications LLC 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value [62]               (60.1)             0.0
Investment, Identifier [Axis]: Sorenson Communications LLC 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               0.0             0.0
Investment, Identifier [Axis]: Sorenson Communications LLC, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0 [61]             $ (67.5) [61],[62]             0.0 [62]
Investment, Identifier [Axis]: Sorenson Communications LLC, Common Stock, Telecommunication Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 42,731 [15],[28],[53],[54] 42,731 [15],[28],[53],[54] 42,731 [15],[28],[53],[54] 42,731 [15],[28],[53],[54] 42,731 [15],[28],[53],[54] 42,731 [15],[28],[53],[54] 42,731 [15],[28],[53],[54] 89,959 [11],[23],[32],[42],[52] 89,959 [11],[23],[32],[42],[52] 89,959 [11],[23],[32],[42],[52] 89,959 [11],[23],[32],[42],[52] 89,959 [11],[23],[32],[42],[52] 89,959 [11],[23],[32],[42],[52] 89,959 [11],[23],[32],[42],[52]  
Amortized cost $ 7.1 [15],[28],[53],[54]             $ 42.5 [11],[23],[32],[42],[52]              
Fair value $ 0.0 [1],[15],[28],[53],[54]             (67.5) [2],[11],[23],[32],[42],[52]              
Investment, Identifier [Axis]: Sorenson Communications LLC, Telecommunication Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[18],[19],[37] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [13],[18],[19],[37] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [13],[17],[18],[19],[37] $ 33.6                            
Amortized cost [13],[18],[19],[37] 31.9                            
Fair value [3],[13],[18],[19],[37] (32.2)                            
Investment, Identifier [Axis]: Sorenson Communications LLC, Telecommunication Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [15],[17],[28],[53],[54] 9.9                            
Amortized cost [15],[28],[53],[54] 8.9                            
Fair value [3],[15],[28],[53],[54] (9.3)                            
Investment, Identifier [Axis]: Sorenson Communications LLC, Telecommunication Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [15],[17],[28],[53],[54] 40.3                            
Amortized cost [15],[28],[53],[54] 32.0                            
Fair value [3],[15],[28],[53],[54] (34.1)                            
Investment, Identifier [Axis]: Sound United LLC 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               0.0             (14.9)
Investment, Identifier [Axis]: Sound United LLC 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               0.0             (20.9)
Investment, Identifier [Axis]: Sound United LLC, Class A Units                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               0.0             0.0
Investment, Identifier [Axis]: Sound United LLC, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ (77.5)             (29.3)
Investment, Identifier [Axis]: Sound United LLC, Common Stock, Consumer Durables & Apparel                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 532,768 [15],[28] 532,768 [15],[28] 532,768 [15],[28] 532,768 [15],[28] 532,768 [15],[28] 532,768 [15],[28] 532,768 [15],[28] 12,857,143 [31],[32] 12,857,143 [31],[32] 12,857,143 [31],[32] 12,857,143 [31],[32] 12,857,143 [31],[32] 12,857,143 [31],[32] 12,857,143 [31],[32]  
Amortized cost $ 0.7 [15],[28]             $ 17.3 [31],[32]              
Fair value $ (7.0) [1],[15],[28]             (77.5) [2],[31],[32]              
Investment, Identifier [Axis]: Sound United LLC, Series I Units                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               0.0             0.0
Investment, Identifier [Axis]: Sound United LLC, Series II Units                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               $ 0.0             0.0
Investment, Identifier [Axis]: Source Code LLC, Senior Secured Loans—First Lien, Software & Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[9],[38]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base rate floor [8],[9],[38]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[8],[9],[38]               $ 53.3              
Amortized cost [8],[9],[38]               52.3              
Fair value [2],[8],[9],[38]               $ (52.2)              
Investment, Identifier [Axis]: Source Code LLC, Senior Secured Loans—First Lien, Software & Services -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 15.3              
Amortized cost [5]               15.0              
Fair value [2],[5]               $ (15.0)              
Investment, Identifier [Axis]: Source Code LLC, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12],[13],[14],[19] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [13],[14],[19] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[14],[17],[19] $ 52.8                            
Amortized cost [13],[14],[19] 51.9                            
Fair value [3],[13],[14],[19] $ (51.3)                            
Investment, Identifier [Axis]: Source Code LLC, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 15.3                            
Amortized cost [4] 15.0                            
Fair value [3],[4] $ (14.8)                            
Investment, Identifier [Axis]: Spins LLC, FSK CLO, Senior Secured Loans—First Lien, Software & Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[33],[38],[39]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [32],[33],[38],[39]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[33],[38],[39]               $ 60.7              
Amortized cost [32],[33],[38],[39]               57.3              
Fair value [2],[32],[33],[38],[39]               $ (61.3)              
Investment, Identifier [Axis]: Spins LLC, FSK CLO, Senior Secured Loans—First Lien, Software & Services -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 7.9              
Amortized cost [5]               7.9              
Fair value [2],[5]               $ (7.9)              
Investment, Identifier [Axis]: Spins LLC, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [15],[19],[34],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[19],[34],[40] $ 68.2                            
Amortized cost [15],[19],[34],[40] 65.4                            
Fair value [3],[15],[19],[34],[40] $ (68.2)                            
Investment, Identifier [Axis]: Spins LLC, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 16.5                            
Amortized cost [4] 16.5                            
Fair value [3],[4] $ (16.5)                            
Investment, Identifier [Axis]: Spins LLC, Software & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 7.9                            
Amortized cost [4] 7.9                            
Fair value [3],[4] $ (7.9)                            
Investment, Identifier [Axis]: Staples Canada                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [24],[32]               7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%  
Base rate floor [24],[32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[24],[32]                           $ 35.8  
Amortized cost [24],[32]               $ 28.0              
Fair value [2],[24],[32]               $ (29.1)              
Investment, Identifier [Axis]: Staples Canada | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 57.0                            
Fair value $ (55.6)                            
Investment, Identifier [Axis]: Staples Canada 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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                           $ 87.0  
Amortized cost               $ 67.1              
Fair value               $ (70.8)              
Investment, Identifier [Axis]: Staples Canada, Retailing                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 7.00% 7.00% 7.00% 7.00% 7.00% 7.00% 7.00%                
Base rate floor [15],[29] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[29]             $ 30.5                
Amortized cost [15],[29] $ 23.9                            
Fair value [3],[15],[29] $ (22.9)                            
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 23,500,000 [29],[55] 23,500,000 [29],[55] 23,500,000 [29],[55] 23,500,000 [29],[55] 23,500,000 [29],[55] 23,500,000 [29],[55] 23,500,000 [29],[55] 23,500,000 [6],[24],[56] 23,500,000 [6],[24],[56] 23,500,000 [6],[24],[56] 23,500,000 [6],[24],[56] 23,500,000 [6],[24],[56] 23,500,000 [6],[24],[56] 23,500,000 [6],[24],[56]  
Amortized cost $ 23.5 [29],[55]             $ 23.5 [24],[56]              
Fair value $ (23.8) [3],[29],[55]             (24.3) [2],[24],[56]              
Investment, Identifier [Axis]: Star Mountain Strategic Credit Income Fund IV LP, Private Equity | 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 $ 42.5                            
Fair value $ (44.0)                            
Investment, Identifier [Axis]: Strategic Credit Opportunities Partners, LLC 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               $ (1,396.2)             (712.5)
Investment, Identifier [Axis]: Stuart Weitzman Inc, Common Stock, Consumer Durables & Apparel                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 5,451 [15],[28] 5,451 [15],[28] 5,451 [15],[28] 5,451 [15],[28] 5,451 [15],[28] 5,451 [15],[28] 5,451 [15],[28] 5,451 [23],[32] 5,451 [23],[32] 5,451 [23],[32] 5,451 [23],[32] 5,451 [23],[32] 5,451 [23],[32] 5,451 [23],[32]  
Amortized cost $ 0.0 [15],[28]             $ 0.0 [23],[32]              
Fair value $ 0.0 [1],[15],[28]             $ 0.0 [2],[23],[32]              
Investment, Identifier [Axis]: Summit Interconnect Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 19.5             $ 10.1              
Amortized cost 19.3             10.0              
Fair value $ (18.4)             $ (10.0)              
Investment, Identifier [Axis]: Summit Interconnect Inc, Senior Secured Loans—First Lien, Capital Goods-1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[9],[32],[38],[43]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [8],[9],[32],[38],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[8],[9],[32],[38],[43]               $ 107.9              
Amortized cost [8],[9],[32],[38],[43]               106.8              
Fair value [2],[8],[9],[32],[38],[43]               $ (106.9)              
Investment, Identifier [Axis]: Summit Interconnect Inc, Senior Secured Loans—First Lien, Capital Goods-2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 48.7              
Amortized cost [5]               48.7              
Fair value [2],[5]               $ (48.2)              
Investment, Identifier [Axis]: Summit Interconnect Inc, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [13],[14],[15],[18],[19],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[14],[15],[17],[18],[19],[40] $ 136.5                            
Amortized cost [13],[14],[15],[18],[19],[40] 135.4                            
Fair value [3],[13],[14],[15],[18],[19],[40] $ (128.7)                            
Investment, Identifier [Axis]: Summit Interconnect Inc, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 9.4                            
Amortized cost [4] 9.4                            
Fair value [3],[4] (8.9)                            
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [20],[23],[32],[42]               4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00%  
Interest rate, paid in kind [20],[23],[32],[42]               2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80%  
Base rate floor [20],[23],[32],[42]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[20],[23],[32],[42]               $ 14.6              
Amortized cost [20],[23],[32],[42]               13.7              
Fair value [2],[20],[23],[32],[42]               $ (8.3)              
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[32],[42]               2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80%  
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value [61] (0.5)             $ (6.0)              
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value 0.0 [61]             (8.3) [61]             0.0
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value [62]               (6.0)             0.0
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value [61] $ (2.0)             $ 0.0              
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc, Senior Secured Loans, First Lien                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[42]               3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75%  
Interest rate, paid in kind [32],[42]               3.80% 3.80% 3.80% 3.80% 3.80% 3.80% 3.80%  
Base rate floor [32],[42]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[42]               $ 5.8              
Amortized cost [32],[42]               5.7              
Fair value [2],[32],[42]               $ (6.0)              
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc, Senior Secured Loans, First Lien | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32],[42]               3.80% 3.80% 3.80% 3.80% 3.80% 3.80% 3.80%  
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value [62]               $ 0.0             0.0
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc, Common Stock, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [23],[32],[33],[42],[52]               262,516 262,516 262,516 262,516 262,516 262,516 262,516  
Amortized cost [23],[32],[33],[42],[52]               $ 6.9              
Fair value [2],[23],[32],[33],[42],[52]               0.0              
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Interest rate, paid in kind [12] 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%                
Base rate floor [15],[41] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount [15],[17],[41] $ 2.0                            
Amortized cost [15],[41] 2.0                            
Fair value [3],[15],[41] $ (2.0)                            
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc, Software & Services 1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%                
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75%                
Interest rate, paid in kind [12] 3.80% 3.80% 3.80% 3.80% 3.80% 3.80% 3.80%                
Base rate floor [15],[25],[28],[41] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[25],[28],[41] $ 6.1                            
Amortized cost [15],[25],[28],[41] 5.8                            
Fair value [3],[15],[25],[28],[41] $ (0.5)                            
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc, Software & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Interest rate, paid in kind [12] 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%                
Base rate floor [4],[41] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount [4],[17],[41] $ 1.2                            
Amortized cost [4],[41] 1.2                            
Fair value [3],[4],[41] $ (1.2)                            
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc, Software & Services 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 4.00% 4.00% 4.00% 4.00% 4.00% 4.00% 4.00%                
Interest rate, paid in kind [12] 2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80%                
Base rate floor [15],[25],[28],[41] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[25],[28],[41] $ 15.1                            
Amortized cost [15],[25],[28],[41] 13.5                            
Fair value [3],[15],[25],[28],[41] $ 0.0                            
Investment, Identifier [Axis]: Sungard Availability Services Capital Inc, Software & Services 4 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 2.80% 2.80% 2.80% 2.80% 2.80% 2.80% 2.80%                
Investment, Identifier [Axis]: Sungard Availbaility Services Capital Inc, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ 0.0              
Investment, Identifier [Axis]: Sweeping Corp of America Inc, Commercial & Professional Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [15],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[40] $ 72.2                            
Amortized cost [15],[40] 70.2                            
Fair value [3],[15],[40] $ (72.2)                            
Investment, Identifier [Axis]: Sweeping Corp of America Inc, Commercial & Professional Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 1.0                            
Amortized cost [15] 1.0                            
Fair value [3],[15] $ (1.0)                            
Investment, Identifier [Axis]: Sweeping Corp of America Inc, Commercial & Professional Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 4.7                            
Amortized cost [4] 4.7                            
Fair value [3],[4] $ (4.7)                            
Investment, Identifier [Axis]: Sweeping Corp of America Inc, Senior Secured Loans—First Lien, Commercial & Professional Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[39]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [32],[39]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[39]               $ 55.8              
Amortized cost [32],[39]               53.3              
Fair value [2],[32],[39]               $ (56.3)              
Investment, Identifier [Axis]: Sweeping Corp of America Inc, Senior Secured Loans—First Lien, Commercial & Professional Services -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32]               $ 1.8              
Amortized cost [32]               1.8              
Fair value [2],[32]               $ (1.8)              
Investment, Identifier [Axis]: Sweeping Corp of America Inc, Senior Secured Loans—First Lien, Commercial & Professional Services -3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 17.2              
Amortized cost [5]               17.2              
Fair value [2],[5]               $ (17.3)              
Investment, Identifier [Axis]: Sweeping Corp of America Inc, Senior Secured Loans—First Lien, Commercial & Professional Services -4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 3.9              
Amortized cost [5]               3.9              
Fair value [2],[5]               $ (3.9)              
Investment, Identifier [Axis]: Swift Worldwide Resources Holdco Ltd, Common Stock, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 1,250,000 [15],[28] 1,250,000 [15],[28] 1,250,000 [15],[28] 1,250,000 [15],[28] 1,250,000 [15],[28] 1,250,000 [15],[28] 1,250,000 [15],[28] 1,250,000 [23],[32] 1,250,000 [23],[32] 1,250,000 [23],[32] 1,250,000 [23],[32] 1,250,000 [23],[32] 1,250,000 [23],[32] 1,250,000 [23],[32]  
Amortized cost $ 1.2 [15],[28]             $ 1.2 [23],[32]              
Fair value $ (1.0) [1],[15],[28]             $ (1.1) [2],[23],[32]              
Investment, Identifier [Axis]: TIBCO Software Inc, Preferred Stock, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15] 12.00% 12.00% 12.00% 12.00% 12.00% 12.00% 12.00%                
Base rate floor [15] 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Number of shares | shares [15] 133,186,150 133,186,150 133,186,150 133,186,150 133,186,150 133,186,150 133,186,150                
Amortized cost [15] $ 127.3                            
Fair value [1],[15] $ (129.6)                            
Investment, Identifier [Axis]: TIBCO Software Inc, Preferred Stock, Software & Services | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15] 12.00% 12.00% 12.00% 12.00% 12.00% 12.00% 12.00%                
Investment, Identifier [Axis]: TIBCO Software Inc, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 4.50% 4.50% 4.50% 4.50% 4.50% 4.50% 4.50%                
Base rate floor [15],[37] 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount [15],[17],[37] $ 39.9                            
Amortized cost [15],[37] 36.4                            
Fair value [3],[15],[37] (35.7)                            
Investment, Identifier [Axis]: TIBCO Software Inc, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [15],[17],[37] 1.0                            
Amortized cost [15],[37] 0.8                            
Fair value [3],[15],[37] $ (0.8)                            
Investment, Identifier [Axis]: Tangoe LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [10],[32],[33],[39],[43]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base rate floor [10],[32],[33],[39],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[10],[32],[33],[39],[43]               $ 190.2              
Amortized cost [10],[32],[33],[39],[43]               171.5              
Fair value [2],[10],[32],[33],[39],[43]               $ (147.2)              
Investment, Identifier [Axis]: Tangoe LLC, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [15],[34],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[34],[40] $ 179.5                            
Amortized cost [15],[34],[40] 165.3                            
Fair value [3],[15],[34],[40] $ (147.2)                            
Investment, Identifier [Axis]: Tangoe LLC, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 12.50% 12.50% 12.50% 12.50% 12.50% 12.50% 12.50%                
Principal amount [15],[17],[34],[40] $ 3.3                            
Amortized cost [15],[34],[40] 3.3                            
Fair value [3],[15],[34],[40] $ (2.6)                            
Investment, Identifier [Axis]: Tangoe LLC, Software & Services 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 12.50% 12.50% 12.50% 12.50% 12.50% 12.50% 12.50%                
Investment, Identifier [Axis]: TeamSystem SpA, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [15],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | € [15],[17],[29]       € 19.8                      
Amortized cost [15],[29] $ 18.9                            
Fair value [3],[15],[29] (21.4)                            
Investment, Identifier [Axis]: Tekfor HoldCo (formerly Amtek Global Technology Pte Ltd), Automobiles & Components                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount | € [15],[17],[28],[29],[30]       € 36.7                      
Amortized cost [15],[28],[29],[30] 40.1                            
Fair value [3],[15],[28],[29],[30] (3.9)                            
Investment, Identifier [Axis]: ThermaSys Corp                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[32],[42]               11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%  
Base rate floor [20],[23],[32],[42]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[20],[23],[32],[42]               $ 8.5              
Amortized cost [20],[23],[32],[42]               8.3              
Fair value $ (8.6)             $ (3.5) [2],[20],[23],[32],[42]             (3.9)
Investment, Identifier [Axis]: ThermaSys Corp | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [20],[23],[32],[42]               11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%  
Investment, Identifier [Axis]: ThermaSys Corp, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%                
Base rate floor [15],[25],[28],[41] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[25],[28],[41] $ 9.7                            
Amortized cost [15],[25],[28],[41] 8.3                            
Fair value [3],[15],[25],[28],[41] $ (8.6)                            
Investment, Identifier [Axis]: ThermaSys Corp, Capital Goods | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 11.00% 11.00% 11.00% 11.00% 11.00% 11.00% 11.00%                
Investment, Identifier [Axis]: ThermaSys Corp, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ 0.0             0.0
Investment, Identifier [Axis]: ThermaSys Corp, Common Stock, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 17,383,026 [15],[28],[41],[53] 17,383,026 [15],[28],[41],[53] 17,383,026 [15],[28],[41],[53] 17,383,026 [15],[28],[41],[53] 17,383,026 [15],[28],[41],[53] 17,383,026 [15],[28],[41],[53] 17,383,026 [15],[28],[41],[53] 17,383,026 [23],[32],[42],[52] 17,383,026 [23],[32],[42],[52] 17,383,026 [23],[32],[42],[52] 17,383,026 [23],[32],[42],[52] 17,383,026 [23],[32],[42],[52] 17,383,026 [23],[32],[42],[52] 17,383,026 [23],[32],[42],[52]  
Amortized cost $ 10.2 [15],[28],[41],[53]             $ 10.2 [23],[32],[42],[52]              
Fair value 0.0 [1],[15],[28],[41],[53]             0.0 [2],[23],[32],[42],[52]              
Investment, Identifier [Axis]: ThermaSys Corp, Preferred Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ 0.0             0.0
Investment, Identifier [Axis]: ThermaSys Corp, Preferred Stock, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 1,529 [15],[28],[41] 1,529 [15],[28],[41] 1,529 [15],[28],[41] 1,529 [15],[28],[41] 1,529 [15],[28],[41] 1,529 [15],[28],[41] 1,529 [15],[28],[41] 1,529 [23],[32],[42] 1,529 [23],[32],[42] 1,529 [23],[32],[42] 1,529 [23],[32],[42] 1,529 [23],[32],[42] 1,529 [23],[32],[42] 1,529 [23],[32],[42]  
Amortized cost $ 1.7 [15],[28],[41]             $ 1.7 [23],[32],[42]              
Fair value $ 0.0 [1],[15],[28],[41]             $ 0.0 [2],[23],[32],[42]              
Investment, Identifier [Axis]: ThreeSixty Group, Retailing 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%                
Interest rate, paid in kind [12] 2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%                
Base rate floor [15],[18],[40] 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50%                
Principal amount [15],[17],[18],[40] $ 46.1                            
Amortized cost [15],[18],[40] 46.1                            
Fair value [3],[15],[18],[40] $ (45.1)                            
Investment, Identifier [Axis]: ThreeSixty Group, Retailing 1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%                
Investment, Identifier [Axis]: ThreeSixty Group, Retailing 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%                
Interest rate, paid in kind [12] 2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%                
Base rate floor [15],[40] 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50%                
Principal amount [15],[17],[40] $ 45.9                            
Amortized cost [15],[40] 45.9                            
Fair value [3],[15],[40] $ (44.8)                            
Investment, Identifier [Axis]: ThreeSixty Group, Retailing 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%                
Investment, Identifier [Axis]: ThreeSixty Group, Senior Secured Loans—First Lien, Retailing -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[39]               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Interest rate, paid in kind [32],[39]               2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%  
Base rate floor [32],[39]               1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50%  
Principal amount [6],[32],[39]               $ 48.5              
Amortized cost [32],[39]               48.4              
Fair value [2],[32],[39]               $ (47.7)              
Investment, Identifier [Axis]: ThreeSixty Group, Senior Secured Loans—First Lien, Retailing -1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32],[39]               2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%  
Investment, Identifier [Axis]: ThreeSixty Group, Senior Secured Loans—First Lien, Retailing -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[39]               5.00% 5.00% 5.00% 5.00% 5.00% 5.00% 5.00%  
Interest rate, paid in kind [32],[39]               2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%  
Base rate floor [32],[39]               1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50%  
Principal amount [6],[32],[39]               $ 48.3              
Amortized cost [32],[39]               48.1              
Fair value [2],[32],[39]               $ (47.4)              
Investment, Identifier [Axis]: ThreeSixty Group, Senior Secured Loans—First Lien, Retailing -2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [32],[39]               2.50% 2.50% 2.50% 2.50% 2.50% 2.50% 2.50%  
Investment, Identifier [Axis]: Time Manufacturing Co | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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             € 29.5        
Amortized cost $ 32.4             $ 32.7              
Fair value $ (29.4)             $ (32.9)              
Investment, Identifier [Axis]: Time Manufacturing Co, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 45.4                            
Amortized cost [15] 44.5                            
Fair value [3],[15] $ (42.7)                            
Investment, Identifier [Axis]: Time Manufacturing Co, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 7.3                            
Amortized cost [15] 7.3                            
Fair value [3],[15] $ (6.9)                            
Investment, Identifier [Axis]: Time Manufacturing Co, Capital Goods 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount | € [15],[17]       € 13.7                      
Amortized cost [15] $ 14.4                            
Fair value [3],[15] $ (13.8)                            
Investment, Identifier [Axis]: Time Manufacturing Co, Capital Goods 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 14.8                            
Amortized cost [4] 14.8                            
Fair value [3],[4] (13.9)                            
Investment, Identifier [Axis]: Time Manufacturing Co, Senior Secured Loans—First Lien, Capital Goods - 5                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount | € [5],[6]                     € 15.0        
Amortized cost [5]               $ 17.0              
Fair value [2],[5]               $ (17.2)              
Investment, Identifier [Axis]: Time Manufacturing Co, Senior Secured Loans—First Lien, Capital Goods -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base rate floor [32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[32]               $ 45.8              
Amortized cost [32]               44.8              
Fair value [2],[32]               $ (44.8)              
Investment, Identifier [Axis]: Time Manufacturing Co, Senior Secured Loans—First Lien, Capital Goods -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base rate floor [32]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [6],[32]               $ 5.3              
Amortized cost [32]               5.3              
Fair value [2],[32]               $ (5.3)              
Investment, Identifier [Axis]: Time Manufacturing Co, Senior Secured Loans—First Lien, Capital Goods -3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 13.7              
Amortized cost [5]               13.7              
Fair value [2],[5]               $ (13.6)              
Investment, Identifier [Axis]: Time Manufacturing Co, Senior Secured Loans—First Lien, Capital Goods -4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base rate floor [5]               0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%  
Principal amount [5],[6]               $ 4.5              
Amortized cost [5]               4.5              
Fair value [2],[5]               (4.5)              
Investment, Identifier [Axis]: Toorak Capital Funding LLC, Membership Interest                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             $ (1.7)             (6.6)
Investment, Identifier [Axis]: Toorak Capital Funding LLC, Membership Interest, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [6],[23],[24],[31],[32]               1,723,140 1,723,140 1,723,140 1,723,140 1,723,140 1,723,140 1,723,140  
Amortized cost [23],[24],[31],[32]               $ 1.9              
Fair value [2],[23],[24],[31],[32]               (1.7)              
Investment, Identifier [Axis]: Toorak Capital LLC, Membership Interest                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               $ (199.3)             (235.9)
Investment, Identifier [Axis]: Toorak Capital Partners LLC, Private Equity 1 | 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               $ 50.2              
Fair value               $ (50.4)              
Investment, Identifier [Axis]: Toorak Capital Partners LLC, Private Equity, Real Estate                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [6],[31],[32]               158,139,270 158,139,270 158,139,270 158,139,270 158,139,270 158,139,270 158,139,270  
Amortized cost [31],[32]               $ 158.1              
Fair value [2],[31],[32]               (199.3)              
Investment, Identifier [Axis]: Toorak Capital Partners LLC, Structured Mezzanine                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value               $ (22.0)             0.0
Investment, Identifier [Axis]: Toorak Capital Partners LLC, Structured Mezzanine, Real Estate 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [7],[31],[32]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Principal amount [6],[31],[32]               $ 22.0              
Amortized cost [31],[32]               22.0              
Fair value [2],[31],[32]               $ (22.0)              
Investment, Identifier [Axis]: Toorak Capital Partners LLC, Structured Mezzanine, Real Estate 1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [7],[31],[32]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Investment, Identifier [Axis]: Toorak Capital Partners LLC, Structured Mezzanine, Real Estate 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [5],[7],[31]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Principal amount [5],[6],[31]               $ 8.0              
Amortized cost [5],[31]               8.0              
Fair value [2],[5],[31]               $ (8.0)              
Investment, Identifier [Axis]: Toorak Capital Partners LLC, Structured Mezzanine, Real Estate 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [5],[7],[31]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Investment, Identifier [Axis]: Total Safety US Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 11.2             $ 11.8              
Amortized cost 10.1             10.4              
Fair value $ (10.6)             $ (11.7)              
Investment, Identifier [Axis]: Transaction Services Group Ltd | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 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           $ 124.1             $ 162.0    
Amortized cost $ 85.3             $ 110.9              
Fair value $ (82.6)             $ (115.2)              
Investment, Identifier [Axis]: Transaction Services Group Ltd, Senior Secured Loans—First Lien, Software & Services -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [24],[32]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base rate floor [24],[32]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount [6],[24],[32]               $ 13.9              
Amortized cost [24],[32]               17.7              
Fair value [2],[24],[32]               $ (18.3)              
Investment, Identifier [Axis]: Transaction Services Group Ltd, Senior Secured Loans—First Lien, Software & Services -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [24],[32]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base rate floor [24],[32]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | £ [6]                       £ 80.3      
Amortized cost               $ 55.7              
Fair value [2]               $ (57.0)              
Investment, Identifier [Axis]: Transaction Services Group Ltd, Senior Secured Loans—First Lien, Software & Services -3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [24],[32]               6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%  
Base rate floor [24],[32]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount [6],[24],[32]                         $ 126.2    
Amortized cost [24],[32]               $ 122.2              
Fair value [2],[24],[32]               (123.1)              
Investment, Identifier [Axis]: Transaction Services Group Ltd, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [15],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount [15],[17],[29]           $ 48.3                  
Amortized cost [15],[29] $ 34.2                            
Fair value [3],[15],[29] $ (32.1)                            
Investment, Identifier [Axis]: Transaction Services Group Ltd, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 5.50% 5.50% 5.50% 5.50% 5.50% 5.50% 5.50%                
Base rate floor [15],[18],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount [15],[17],[18],[29] $ 126.2                            
Amortized cost [15],[18],[29] 122.9                            
Fair value [3],[15],[18],[29] (123.5)                            
Investment, Identifier [Axis]: TruckPro LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [6],[32],[36]               9.2              
Amortized cost [32],[36]               9.2              
Fair value [2],[32],[36]               $ (10.0)              
Investment, Identifier [Axis]: TruckPro LLC, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Principal amount [15],[17],[37] 9.2                            
Amortized cost [15],[37] 9.2                            
Fair value [3],[15],[37] $ (9.1)                            
Investment, Identifier [Axis]: Ultra Electronics Holdings PLC, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75%                
Base rate floor [15],[29],[37] 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount [15],[17],[29],[37] $ 1.8                            
Amortized cost [15],[29],[37] 1.8                            
Fair value [3],[15],[29],[37] $ (1.7)                            
Investment, Identifier [Axis]: Ultra Electronics Holdings PLC, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 3.75% 3.75% 3.75% 3.75% 3.75% 3.75% 3.75%                
Base rate floor [15],[29],[37] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | € [15],[17],[29],[37]       € 1.4                      
Amortized cost [15],[29],[37] $ 1.6                            
Fair value [3],[15],[29],[37] $ (1.4)                            
Investment, Identifier [Axis]: Ultra Electronics Holdings PLC, Capital Goods 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 7.25% 7.25% 7.25% 7.25% 7.25% 7.25% 7.25%                
Base rate floor [15],[29] 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount [15],[17],[29] $ 62.9                            
Amortized cost [15],[29] 61.1                            
Fair value [3],[15],[29] $ (58.2)                            
Investment, Identifier [Axis]: Ultra Electronics Holdings PLC, Capital Goods 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%                
Interest rate, paid in kind [12] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor [15],[29] 0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%                
Principal amount [15],[17],[29] $ 58.2                            
Amortized cost [15],[29] 56.5                            
Fair value [3],[15],[29] $ (53.4)                            
Investment, Identifier [Axis]: Ultra Electronics Holdings PLC, Capital Goods 4 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%                
Investment, Identifier [Axis]: Ultra Electronics Holdings PLC, Private Equity, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [15],[28],[29] 683,240,044 683,240,044 683,240,044 683,240,044 683,240,044 683,240,044 683,240,044                
Amortized cost [15],[28],[29] $ 7.2                            
Fair value [1],[15],[28],[29] $ (6.7)                            
Investment, Identifier [Axis]: Ultra Electronics Holdings PLC, Private Equity, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [15],[28],[29] 1,272,105 1,272,105 1,272,105 1,272,105 1,272,105 1,272,105 1,272,105                
Amortized cost [15],[28],[29] $ 1.3                            
Fair value [1],[15],[28],[29] $ (1.2)                            
Investment, Identifier [Axis]: Unifrax I LLC / Unifrax Holding Co | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 2.8                            
Amortized cost 2.7                            
Fair value $ (2.5)                            
Investment, Identifier [Axis]: Valeo Foods Group Ltd | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount | £         £ 9.3                    
Amortized cost $ 11.8                            
Fair value $ (9.9)                            
Investment, Identifier [Axis]: Valeo Foods Group Ltd, Food, Beverage & Tobacco 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%                
Base rate floor [15],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | € [15],[17],[29]       € 3.8                      
Amortized cost [15],[29] $ 4.0                            
Fair value [3],[15],[29] $ (3.6)                            
Investment, Identifier [Axis]: Valeo Foods Group Ltd, Food, Beverage & Tobacco 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%                
Base rate floor [4],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | € [4],[17],[29]       € 2.3                      
Amortized cost [4],[29] $ 3.1                            
Fair value [3],[4],[29] $ (2.8)                            
Investment, Identifier [Axis]: Valeo Foods Group Ltd, Senior Secured Loans—Second Lien, Food, Beverage & Tobacco -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [24],[32]               8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00%  
Base rate floor [24],[32]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | £ [6],[24],[32]                       £ 9.3      
Amortized cost [24],[32]               $ 12.3              
Fair value [2],[24],[32]               $ (12.2)              
Investment, Identifier [Axis]: Valeo Foods Group Ltd, Senior Secured Loans—Second Lien, Food, Beverage & Tobacco -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5],[24]               7.50% 7.50% 7.50% 7.50% 7.50% 7.50% 7.50%  
Base rate floor [5],[24]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | € [5],[6],[24]                     € 6.2        
Amortized cost [5],[24]               $ 7.2              
Fair value [2],[5],[24]               $ (6.8)              
Investment, Identifier [Axis]: Vantage Specialty Chemicals Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [32],[36]               8.25% 8.25% 8.25% 8.25% 8.25% 8.25% 8.25%  
Base rate floor [32],[36]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[32],[36]               $ 0.8              
Amortized cost [32],[36]               0.7              
Fair value [2],[32],[36]               $ (0.7)              
Investment, Identifier [Axis]: Vantage Specialty Chemicals Inc, Materials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 8.25% 8.25% 8.25% 8.25% 8.25% 8.25% 8.25%                
Base rate floor [15],[37] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[37] $ 0.8                            
Amortized cost [15],[37] 0.7                            
Fair value [3],[15],[37] $ (0.7)                            
Investment, Identifier [Axis]: Varsity Brands Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 4.0                            
Amortized cost 3.8                            
Fair value $ (3.8)                            
Investment, Identifier [Axis]: Versatile Processing Group Inc, Class A - 2 Units, Materials                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 3,637,500 [28],[53] 3,637,500 [28],[53] 3,637,500 [28],[53] 3,637,500 [28],[53] 3,637,500 [28],[53] 3,637,500 [28],[53] 3,637,500 [28],[53] 3,637,500 [23],[52] 3,637,500 [23],[52] 3,637,500 [23],[52] 3,637,500 [23],[52] 3,637,500 [23],[52] 3,637,500 [23],[52] 3,637,500 [23],[52]  
Amortized cost $ 3.6 [28],[53]             $ 3.6 [23],[52]              
Fair value $ 0.0 [1],[28],[53]             0.0 [2],[23],[52]              
Investment, Identifier [Axis]: Version1 Software Ltd 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Interest rate, paid in kind 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | €       € 2.5                      
Amortized cost $ 2.5                            
Fair value $ (2.5)                            
Investment, Identifier [Axis]: Version1 Software Ltd 1 | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 1.70% 1.70% 1.70% 1.70% 1.70% 1.70% 1.70%                
Investment, Identifier [Axis]: Version1 Software Ltd 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Interest rate, paid in kind 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | £         £ 4.0                    
Amortized cost $ 4.7                            
Fair value $ (4.7)                            
Investment, Identifier [Axis]: Version1 Software Ltd 2 | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 1.70% 1.70% 1.70% 1.70% 1.70% 1.70% 1.70%                
Investment, Identifier [Axis]: Version1 Software Ltd, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Interest rate, paid in kind [12] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor [4],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | € [4],[17],[29]       € 2.4                      
Amortized cost [4],[29] $ 2.4                            
Fair value [3],[4],[29] $ (2.3)                            
Investment, Identifier [Axis]: Version1 Software Ltd, Software & Services | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 1.70% 1.70% 1.70% 1.70% 1.70% 1.70% 1.70%                
Investment, Identifier [Axis]: VetCor Professional Practices LLC, Health Care Equipment & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 82.3                            
Amortized cost [15] 81.5                            
Fair value [3],[15] $ (80.9)                            
Investment, Identifier [Axis]: VetCor Professional Practices LLC, Health Care Equipment & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 1.8                            
Amortized cost [15] 1.7                            
Fair value [3],[15] $ (1.8)                            
Investment, Identifier [Axis]: VetCor Professional Practices LLC, Health Care Equipment & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 11.0                            
Amortized cost [4] 10.9                            
Fair value [3],[4] $ (10.8)                            
Investment, Identifier [Axis]: VetCor Professional Practices LLC, Health Care Equipment & Services 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 5.75% 5.75% 5.75% 5.75% 5.75% 5.75% 5.75%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 4.9                            
Amortized cost [4] 4.9                            
Fair value [3],[4] (4.8)                            
Investment, Identifier [Axis]: Warren Resources Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value (18.6)             $ (18.7) [57]             0.0 [57]
Investment, Identifier [Axis]: Warren Resources Inc 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [31],[32]               9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%  
Interest rate, paid in kind [31],[32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Base rate floor [31],[32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[31],[32]               $ 18.7              
Amortized cost [31],[32]               17.4              
Fair value [2],[31],[32]               (18.7)              
Investment, Identifier [Axis]: Warren Resources Inc, Common Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ (29.2)             $ (20.4)             $ 0.0
Investment, Identifier [Axis]: Warren Resources Inc, Common Stock, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares 3,483,788 [15],[28],[30] 3,483,788 [15],[28],[30] 3,483,788 [15],[28],[30] 3,483,788 [15],[28],[30] 3,483,788 [15],[28],[30] 3,483,788 [15],[28],[30] 3,483,788 [15],[28],[30] 3,483,788 [23],[31],[32] 3,483,788 [23],[31],[32] 3,483,788 [23],[31],[32] 3,483,788 [23],[31],[32] 3,483,788 [23],[31],[32] 3,483,788 [23],[31],[32] 3,483,788 [23],[31],[32]  
Amortized cost $ 12.8 [15],[28],[30]             $ 12.8 [23],[31],[32]              
Fair value $ (29.2) [1],[15],[28],[30]             $ (20.4) [2],[23],[31],[32]              
Investment, Identifier [Axis]: Warren Resources Inc, Energy                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 9.00% 9.00% 9.00% 9.00% 9.00% 9.00% 9.00%                
Interest rate, paid in kind [12] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Base rate floor [15],[30] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[30] $ 18.6                            
Amortized cost [15],[30] 17.8                            
Fair value [3],[15],[30] $ (18.6)                            
Investment, Identifier [Axis]: Warren Resources Inc, Energy | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Investment, Identifier [Axis]: Watchfire Enterprises Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               8.25% 8.25% 8.25% 8.25% 8.25% 8.25% 8.25%  
Base rate floor               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount               $ 9.3              
Amortized cost               9.3              
Fair value               $ (9.3)              
Investment, Identifier [Axis]: Wealth Enhancement Group LLC, Diversified Financials 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [15],[29] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17],[29] $ 31.1                            
Amortized cost [15],[29] 31.0                            
Fair value [3],[15],[29] $ (30.7)                            
Investment, Identifier [Axis]: Wealth Enhancement Group LLC, Diversified Financials 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [4],[29] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17],[29] $ 3.3                            
Amortized cost [4],[29] 3.3                            
Fair value [3],[4],[29] $ (3.2)                            
Investment, Identifier [Axis]: Wealth Enhancement Group LLC, Diversified Financials 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [4],[29] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17],[29] $ 2.1                            
Amortized cost [4],[29] 2.1                            
Fair value [3],[4],[29] $ (2.0)                            
Investment, Identifier [Axis]: Wealth Enhancement Group LLC, Senior Secured Loans—First Lien, Diversified Financials - 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [24],[32]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [24],[32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[24],[32]               $ 15.1              
Amortized cost [24],[32]               15.0              
Fair value [2],[24],[32]               $ (15.1)              
Investment, Identifier [Axis]: Wealth Enhancement Group LLC, Senior Secured Loans—First Lien, Diversified Financials -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Base rate floor [24],[32]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[24],[32]               $ 0.7              
Amortized cost [24],[32]               0.7              
Fair value [2],[24],[32]               $ (0.7)              
Investment, Identifier [Axis]: Wealth Enhancement Group LLC, Senior Secured Loans—First Lien, Diversified Financials -3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5],[24]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [5],[24]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6],[24]               $ 13.2              
Amortized cost [5],[24]               13.2              
Fair value [2],[5],[24]               $ (13.2)              
Investment, Identifier [Axis]: Wealth Enhancement Group LLC, Senior Secured Loans—First Lien, Diversified Financials -4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5],[24]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [5],[24]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6],[24]               $ 1.0              
Amortized cost [5],[24]               1.0              
Fair value [2],[5],[24]               $ (1.0)              
Investment, Identifier [Axis]: West Corp 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 12.1                            
Amortized cost 12.0                            
Fair value $ (11.2)                            
Investment, Identifier [Axis]: West Corp 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 2.5                            
Amortized cost 2.5                            
Fair value $ (2.3)                            
Investment, Identifier [Axis]: West Corp L+350 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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               $ 2.6              
Amortized cost               2.5              
Fair value               $ (2.4)              
Investment, Identifier [Axis]: West Corp L+400 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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               $ 12.4              
Amortized cost               12.2              
Fair value               $ (11.8)              
Investment, Identifier [Axis]: Wittur Holding GmbH                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [24],[32]               8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%  
Interest rate, paid in kind [24],[32]               0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Base rate floor [24],[32]               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | € [6],[24],[32]                     € 112.8        
Amortized cost [24],[32]               $ 120.9              
Fair value [2],[24],[32]               $ (120.9)              
Investment, Identifier [Axis]: Wittur Holding GmbH | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%                
Interest rate, paid in kind 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%                
Principal amount | €       € 121.1                      
Amortized cost $ 132.4                            
Fair value $ (92.0)                            
Investment, Identifier [Axis]: Wittur Holding GmbH | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [24],[32]               0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Investment, Identifier [Axis]: Wittur Holding GmbH | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Investment, Identifier [Axis]: Wittur Holding GmbH 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate               8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%  
Interest rate, paid in kind               0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Base rate floor               0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%  
Principal amount | €                     € 120.5        
Amortized cost               $ 131.5              
Fair value               $ (129.3)              
Investment, Identifier [Axis]: Wittur Holding GmbH 1 | Maximum | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind               0.50% 0.50% 0.50% 0.50% 0.50% 0.50% 0.50%  
Investment, Identifier [Axis]: Wittur Holding GmbH, Capital Goods                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 8.50% 8.50% 8.50% 8.50% 8.50% 8.50% 8.50%                
Interest rate, paid in kind [12] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Base rate floor [15],[29] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Principal amount | € [15],[17],[29]       € 113.4                      
Amortized cost [15],[29] $ 122.5                            
Fair value [3],[15],[29] $ (86.1)                            
Investment, Identifier [Axis]: Wittur Holding GmbH, Capital Goods | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Investment, Identifier [Axis]: Woolpert Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 53.0             $ 53.5              
Amortized cost 52.6             53.0              
Fair value $ (51.6)             $ (54.3)              
Investment, Identifier [Axis]: Woolpert Inc, Capital Goods 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [13],[14],[18],[19],[40] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [13],[14],[17],[18],[19],[40] $ 91.0                            
Amortized cost [13],[14],[18],[19],[40] 85.1                            
Fair value [3],[13],[14],[18],[19],[40] $ (88.6)                            
Investment, Identifier [Axis]: Woolpert Inc, Capital Goods 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 68.5                            
Amortized cost [15] 68.5                            
Fair value [3],[15] $ (66.7)                            
Investment, Identifier [Axis]: Woolpert Inc, Capital Goods 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 3.7                            
Amortized cost [4] 3.7                            
Fair value [3],[4] $ (3.6)                            
Investment, Identifier [Axis]: Woolpert Inc, Revolving Credit Facility, Senior Secured Loans—First Lien, Capital Goods -1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[9],[32],[38],[39],[43]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [8],[9],[32],[38],[39],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[8],[9],[32],[38],[39],[43]               $ 139.2              
Amortized cost [8],[9],[32],[38],[39],[43]               132.5              
Fair value [2],[8],[9],[32],[38],[39],[43]               $ (141.2)              
Investment, Identifier [Axis]: Woolpert Inc, Revolving Credit Facility, Senior Secured Loans—First Lien, Capital Goods -2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [5]               6.00% 6.00% 6.00% 6.00% 6.00% 6.00% 6.00%  
Base rate floor [5]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [5],[6]               $ 25.6              
Amortized cost [5]               25.6              
Fair value [2],[5]               $ (25.9)              
Investment, Identifier [Axis]: Worldwise Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 64.7                            
Amortized cost 61.7                            
Fair value $ (59.8)                            
Investment, Identifier [Axis]: Worldwise Inc, Class A Private Equity, Household & Personal Products                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [15],[28] 32,109 32,109 32,109 32,109 32,109 32,109 32,109                
Amortized cost [15],[28] $ 1.6                            
Fair value [1],[15],[28] $ (1.6)                            
Investment, Identifier [Axis]: Worldwise Inc, Class B Private Equity, Household & Personal Products                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [15],[28] 32,109 32,109 32,109 32,109 32,109 32,109 32,109                
Amortized cost [15],[28] $ 1.6                            
Fair value [1],[15],[28] $ (0.4)                            
Investment, Identifier [Axis]: Worldwise Inc, Household & Personal Products 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 26.3                            
Amortized cost [15] 26.3                            
Fair value [3],[15] $ (24.4)                            
Investment, Identifier [Axis]: Worldwise Inc, Household & Personal Products 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 20.0                            
Amortized cost [15] 19.8                            
Fair value [3],[15] $ (18.5)                            
Investment, Identifier [Axis]: Worldwise Inc, Household & Personal Products 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [15] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [15],[17] $ 7.4                            
Amortized cost [15] 7.4                            
Fair value [3],[15] $ (6.8)                            
Investment, Identifier [Axis]: Worldwise Inc, Household & Personal Products 4                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 15.5                            
Amortized cost [4] 15.5                            
Fair value [3],[4] $ (14.4)                            
Investment, Identifier [Axis]: Worldwise Inc, Household & Personal Products 5                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%                
Base rate floor [4] 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%                
Principal amount [4],[17] $ 6.8                            
Amortized cost [4] 6.8                            
Fair value [3],[4] $ (6.3)                            
Investment, Identifier [Axis]: Yak Access LLC | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 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 $ 0.8             $ 0.8              
Amortized cost 0.6             0.6              
Fair value $ (0.3)             $ (0.7)              
Investment, Identifier [Axis]: Yak Access LLC 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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 $ 0.2                            
Amortized cost 0.2                            
Fair value $ (0.2)                            
Investment, Identifier [Axis]: Zendesk Inc, Software & Services 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Interest rate, paid in kind [12] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor [15] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [15],[17] $ 58.1                            
Amortized cost [15] 57.5                            
Fair value [3],[15] $ (57.5)                            
Investment, Identifier [Axis]: Zendesk Inc, Software & Services 1 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50%                
Investment, Identifier [Axis]: Zendesk Inc, Software & Services 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Interest rate, paid in kind [12] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 14.5                            
Amortized cost [4] 14.4                            
Fair value [3],[4] $ (14.4)                            
Investment, Identifier [Axis]: Zendesk Inc, Software & Services 2 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50%                
Investment, Identifier [Axis]: Zendesk Inc, Software & Services 3                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Interest rate, paid in kind [12] 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%                
Base rate floor [4] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17] $ 6.0                            
Amortized cost [4] 6.0                            
Fair value [3],[4] $ (5.9)                            
Investment, Identifier [Axis]: Zendesk Inc, Software & Services 3 | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12] 3.50% 3.50% 3.50% 3.50% 3.50% 3.50% 3.50%                
Investment, Identifier [Axis]: Zeta Interactive Holdings Corp, Common Stock | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares               1,766,696 1,766,696 1,766,696 1,766,696 1,766,696 1,766,696 1,766,696  
Amortized cost               $ 15.1              
Fair value               $ (14.9)              
Investment, Identifier [Axis]: Zeta Interactive Holdings Corp, Common Stock, Software & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Number of shares | shares [23],[32],[36]               3,610,212 3,610,212 3,610,212 3,610,212 3,610,212 3,610,212 3,610,212  
Amortized cost [23],[32],[36]               $ 30.8              
Fair value [2],[23],[32],[36]               (30.4)              
Investment, Identifier [Axis]: athenahealth Inc | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Principal amount $ 5.5                            
Amortized cost 4.8                            
Fair value (4.1)                            
Investment, Identifier [Axis]: athenahealth Inc 1                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             0.0              
Investment, Identifier [Axis]: athenahealth Inc 1 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 7.1                            
Amortized cost 6.4                            
Fair value (6.4)                            
Investment, Identifier [Axis]: athenahealth Inc 2                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Fair value $ 0.0             0.0              
Investment, Identifier [Axis]: athenahealth Inc 2 | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount $ 0.9                            
Amortized cost 0.9                            
Fair value $ (0.8)                            
Investment, Identifier [Axis]: athenahealth Inc, Preferred Stock                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 10.80% 10.80% 10.80% 10.80% 10.80% 10.80% 10.80%                
Fair value $ (231.2)             $ 0.0              
Investment, Identifier [Axis]: athenahealth Inc, Preferred Stock | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
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                
Amortized cost $ 47.5                            
Fair value $ (43.2)                            
Investment, Identifier [Axis]: athenahealth Inc, Preferred Stock | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind 10.80% 10.80% 10.80% 10.80% 10.80% 10.80% 10.80%                
Investment, Identifier [Axis]: athenahealth Inc, Preferred Stock, Health Care Equipment & Services                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15],[41] 10.80% 10.80% 10.80% 10.80% 10.80% 10.80% 10.80%                
Number of shares | shares [15],[41] 267,493 267,493 267,493 267,493 267,493 267,493 267,493                
Amortized cost [15],[41] $ 262.2                            
Fair value [1],[15],[41] $ (231.2)                            
Investment, Identifier [Axis]: athenahealth Inc, Preferred Stock, Health Care Equipment & Services | Maximum                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Interest rate, paid in kind [12],[15],[41] 10.80% 10.80% 10.80% 10.80% 10.80% 10.80% 10.80%                
Investment, Identifier [Axis]: hibu Inc                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [8],[9],[32],[38],[39],[43]               6.25% 6.25% 6.25% 6.25% 6.25% 6.25% 6.25%  
Base rate floor [8],[9],[32],[38],[39],[43]               1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00%  
Principal amount [6],[8],[9],[32],[38],[39],[43]               $ 101.6              
Amortized cost [8],[9],[32],[38],[39],[43]               96.6              
Fair value [2],[8],[9],[32],[38],[39],[43]               $ (104.6)              
Investment, Identifier [Axis]: iNova Pharmaceuticals (Australia) Pty Limited | Credit Opportunities Partners JV, LLC                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate 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%                
Principal amount           $ 34.2                  
Amortized cost $ 22.5                            
Fair value $ (22.6)                            
Investment, Identifier [Axis]: iNova Pharmaceuticals (Australia) Pty Limited, Pharmaceuticals, Biotechnology & Life Sciences                              
Investment Company, Nonconsolidated Subsidiary [Line Items]                              
Variable rate [12] 6.50% 6.50% 6.50% 6.50% 6.50% 6.50% 6.50%                
Base rate floor [4],[29] 0.80% 0.80% 0.80% 0.80% 0.80% 0.80% 0.80%                
Principal amount [4],[17],[29]           $ 3.5                  
Amortized cost [4],[29] $ 2.2                            
Fair value [3],[4],[29] $ (2.2)                            
[1] Fair value determined by the Company’s board of directors (see Note 8).
[2] Fair value determined by the Company’s board of directors (see Note 8).
[3] Listed investments may be treated as debt for GAAP or tax purposes.
[4] Security is an unfunded commitment. Reflects the stated spread at the time of commitment, but may not be the actual rate received upon funding.
[5] Security is an unfunded commitment. Reflects the stated spread at the time of commitment, but may not be the actual rate received upon funding.
[6] Denominated in U.S. dollars unless otherwise noted.
[7] 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, 2020, the three-month London Interbank Offered Rate, or LIBOR or "L", was 0.21%, the Euro Interbank Offered Rate, or EURIBOR, was (0.57)%, Canadian Dollar Offer Rate, or CDOR, was 0.48%, the Bank Bill Swap Bid Rate, or BBSY was 0.12%, the Reykjavik Interbank Offered Rate, or REIBOR, was 2.65%, the Stockholm Interbank Offered Rate, or STIBOR, was (0.05)%, the Sterling Overnight Index Average, or SONIA, was 0.19%, the Secured Overnight Financing Rate, or SOFR, was 0.05%, and the U.S. Prime Lending Rate, or Prime, was 3.25%. PIK means paid-in-kind. PIK income accruals may be adjusted based on the fair value of the underlying investment.
[8] 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).
[9] 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).
[10] 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).
[11] 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).
[12] 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.
[13] 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).
[14] 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).
[15] Security or portion thereof is pledged as collateral supporting the amounts outstanding under the Senior Secured Revolving Credit Facility (see Note 9).
[16] 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).
[17] Denominated in U.S. dollars unless otherwise noted.
[18] 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).
[19] 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).
[20] Asset is on non-accrual status.
[21] Security held within IC Arches Investments LLC, a wholly-owned subsidiary of the Company.
[22] Security held within IC II Arches Investments, LLC, a wholly-owned subsidiary of the Company.
[23] Security is non-income producing
[24] 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, 2021, 75.1% of the Company’s total assets represented qualifying assets.
[25] Asset is on non-accrual status.
[26] Security held within IC Arches Investments LLC, a wholly-owned subsidiary of the Company.
[27] Security held within IC II Arches Investments, LLC, a wholly-owned subsidiary of the Company.
[28] Security is non-income producing.
[29] 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.
[30] 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 and Other 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 LLC 133.3 19.3 (0.3)— 0.2 152.5 12.9 8.0 — — 
 Production Resource Group LLC 0.1 — — — — 0.1 — — — — 
 Production Resource Group LLC 64.4 3.7 (0.6)— 0.6 68.1 6.4 2.0 — — 
 Production Resource Group LLC 20.2 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 — — 
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 and Other Income(3)
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— — — — — — — — — — 
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 Stock 77.5 — (17.3)— (60.2)— — — — — 
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 and Other Income(3)
Warren Resources Inc, Common Stock 20.4 — — — 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 and other 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.
(5)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.
[31] 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, 2021, 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, 2021, 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 as of December 31, 2021:
Portfolio CompanyFair Value at December 31, 2020
Gross Additions(1)
Gross Reductions(2)
Net Realized Gain (Loss)Net Change in Unrealized Appreciation (Depreciation)Fair Value at December 31, 2021
Interest Income(3)
PIK Income(3)
Fee Income(3)
Dividend Income(3)
Senior Secured Loans—First Lien
Advanced Lighting Technologies Inc$12.0 $4.1 $(15.9)$(4.6)$4.4 $— $— $— $— $— 
Amtek Global Technology Pte Ltd59.7 2.4 — — (27.3)34.8 1.1 1.4 — — 
ATX Networks Corp— 46.8 — — — 46.8 1.3 — — — 
 HM Dunn Co Inc(4)
— 49.2 (7.1)(8.5)— 33.6 0.5 — — — 
 HM Dunn Co Inc(4)
— 14.0 (19.0)7.0 — 2.0 0.4 0.8 — — 
One Call Care Management Inc— 9.7 (5.1)0.1 0.3 5.0 0.3 — 0.1 — 
Production Resource Group LLC— 124.9 — — 8.4 133.3 5.4 3.8 — — 
Production Resource Group LLC— 0.1 — — — 0.1 — — — — 
Production Resource Group LLC— 60.6 (0.4)— 4.2 64.4 2.8 0.8 0.4 — 
Production Resource Group LLC— 20.2 (0.1)— 0.1 20.2 0.4 — 0.1 — 
Sound United LLC14.9 — (15.0)— 0.1 — 0.4 — — — 
 Warren Resources Inc(4)
— 19.3 (2.0)0.1 1.3 18.7 1.3 0.1 — — 
Senior Secured Loans—Second Lien
Amtek Global Technology Pte Ltd0.1 (1.8)— (10.4)12.1 — (1.9)— — — 
Sound United LLC20.9 1.7 (22.6)— — — — 1.0 — — 
Other Senior Secured Debt
Advanced Lighting Technologies Inc— — (0.7)(22.9)23.6 — — — — — 
JW Aluminum Co(4)
— 75.5 — — 5.5 81.0 6.2 — — — 
One Call Care Management Inc(4)
— 43.5 (21.9)— 1.9 23.5 0.4 1.6 — — 
Subordinated Debt
ATX Networks Corp— 4.8 — — 2.3 7.1 — — — — 
Hilding Anders32.4 — — — 14.2 46.6 — — — — 
Hilding Anders— — — — — — — — — — 
Portfolio CompanyFair Value at December 31, 2020
Gross Additions(1)
Gross Reductions(2)
Net Realized Gain (Loss)Net Change in Unrealized Appreciation (Depreciation)Fair Value at December 31, 2021
Interest Income(3)
PIK Income(3)
Fee Income(3)
Dividend Income(3)
Hilding Anders30.3 — — — (30.3)— — — — — 
Asset Based Finance
801 5th Ave, Seattle, Structure Mezzanine29.4 25.7 — — 2.1 57.2 3.6 1.3 — — 
801 5th Ave, Seattle, Private Equity10.3 9.6 — — 3.2 23.1 — — — — 
Avida Holding AB, Common Stock38.3 9.1 — — 4.9 52.3 — — — — 
Kilter Finance, Preferred Stock0.2 34.4 — — 1.5 36.1 1.3 1.2 — — 
Kilter Finance, Private Equity0.2 0.3 — — — 0.5 — — — — 
KKR Rocket Loans Aggregator LLC, Partnership Interest— 1.4 — — — 1.4 — — — 0.1 
My Community Homes SFR PropCo 2, Private Equity— 33.0 — — — 33.0 — — — — 
Prime St LLC, Private Equity3.9 4.6 — — 0.6 9.1 — — — — 
Prime St LLC, Structured Mezzanine22.8 27.6 — — 2.0 52.4 0.9 2.2 — — 
Toorak Capital Funding LLC, Membership Interest6.6 1.3 (4.9)— (1.3)1.7 — — — — 
Toorak Capital LLC, Membership Interest235.9 2.3 (50.2)10.2 1.1 199.3 — — — 18.7 
Toorak Capital Partners LLC, Structured Mezzanine— 73.0 (51.0)— — 22.0 0.2 — — — 
Credit Opportunities Partners JV, LLC
Credit Opportunities Partners JV, LLC712.5 586.4 — — 97.3 1,396.2 — — — 126.9 
Equity/Other
Advanced Lighting Technologies Inc, Common Stock— — — (16.5)16.5 — — — — — 
Advanced Lighting Technologies Inc, Warrant— — — (0.1)0.1 — — — — — 
Amtek Global Technology Pte Ltd, Common Stock— — — — — — — — — — 
Amtek Global Technology Pte Ltd, Ordinary Shares— — — — — — — — — — 
Amtek Global Technology Pte Ltd, Trade Claim— — (1.4)0.4 1.0 — — — — — 
Amtek Global Technology Pte Ltd, Private Equity— — — — — — — — — — 
ATX Networks Corp, Common Stock— — — — — — — — — — 
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(4)
— 7.1 — — — 7.1 — — — — 
 HM Dunn Co Inc, Preferred Stock, Series B(4)
— — — — — — — — — — 
 JW Aluminum Co, Common Stock(4)
— — — — — — — — — — 
 JW Aluminum Co, Preferred Stock(4)
— 177.9 — — (55.3)122.6 0.4 20.9 — — 
 One Call Care Management Inc, Common Stock(4)
— 4.5 (2.2)(0.2)0.3 2.4 — — — — 
 One Call Care Management Inc, Preferred Stock A(4)
— 48.6 (23.7)(2.1)3.3 26.1 — — — — 
 One Call Care Management Inc, Preferred Stock B(4)
— 15.7 (8.8)1.1 1.2 9.2 — 0.8 — — 
Production Resource Group LLC, Preferred Stock, Series A PIK— 18.1 — — (0.7)17.4 — — — — 
Portfolio CompanyFair Value at December 31, 2020
Gross Additions(1)
Gross Reductions(2)
Net Realized Gain (Loss)Net Change in Unrealized Appreciation (Depreciation)Fair Value at December 31, 2021
Interest Income(3)
PIK Income(3)
Fee Income(3)
Dividend Income(3)
Production Resource Group LLC, Preferred Stock, Series B PIK— — — — — — — — — — 
Sound United LLC, Class A Units— — — (1.1)1.1 — — — — — 
Sound United LLC, Common Stock29.3 — — — 48.2 77.5 — — — 20.0 
Sound United LLC, Series I Units— — — (0.5)0.5 — — — — — 
Sound United LLC, Series II Units— — — (0.5)0.5 — — — — — 
Warren Resources Inc, Common Stock— 12.8 — — 7.6 20.4 — — — — 
Total$1,259.7 $1,568.4 $(252.0)$(48.5)$156.5 $2,684.1 $25.0 $35.9 $0.6 $165.7 
[32] Security or portion thereof is pledged as collateral supporting the amounts outstanding under the Senior Secured Revolving Credit Facility (see Note 9).
[33] 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).
[34] 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).
[35] Position or portion thereof unsettled as of unsettled as of December 31, 2022.
[36] Security is classified as Level 1 or 2 in the Company's fair value hierarchy (see Note 8).
[37] Security is classified as Level 1 or 2 in the Company's fair value hierarchy (see Note 8).
[38] 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).
[39] Security or portion thereof was held within FSK CLO as of December 31, 2021.
[40] Security or portion thereof was held within FSK CLO as of December 31, 2022.
[41] 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 and Other Income(3)
Senior Secured Loans—First Lien
Affordable Care Inc $— $— $— $— $— $— $— $— $— $— 
Affordable Care Inc 59.9 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 Inc 49.2 4.7 (2.2)(0.2)(42.7)8.8 3.7 2.7 — — 
Belk Inc 21.9 0.1 — — (2.6)19.4 2.2 — — — 
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 and Other Income(3)
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 LLC 15.0 0.4 — — (0.4)15.0 1.8 — — — 
Fairway Group Holdings Corp 0.7 — — (1.0)0.3 — — — — — 
Fairway Group Holdings Corp — — — — — — — — — — 
Micronics Filtration Holdings Inc 51.0 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 Corp 3.5 — — — 5.1 8.6 — — — — 
Senior Secured Loans—Second Lien
 Belk Inc 6.7 — — — (3.4)3.3 — — — — 
 Constellis Holdings LLC 12.0 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 Equity 9.4 — (11.8)6.4 (4.0)— — — — 0.7 
 Home Partners JV, Common Stock 80.6 — (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 Equity 0.1 0.1 — — — 0.2 — — — — 
 Home Partners JV 2, Private Equity 1.6 2.9 — — 0.5 5.0 — — — — 
 Jet Edge International LLC, Preferred Stock 16.8 — (30.1)9.2 4.1 — 0.7 — — — 
 Jet Edge International LLC, Warrant 4.5 — (13.5)13.5 (4.5)— — — — 1.5 
 Jet Edge International LLC, Term Loan 75.6 — (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 Stock 64.6 0.1 (66.0)3.9 (2.6)— — — — — 
Equity/Other
Affordable Care Inc, Common Stock 52.1 — — — (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 — — — — — — — — — — 
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 and Other Income(3)
 Borden (New Dairy Opco), Common Stock 7.7 — — — (2.9)4.8 — — — — 
 Constellis Holdings LLC, Private Equity 0.2 — — — 6.1 6.3 — — — — 
 Fairway Group Holdings Corp, Common Stock — — — — — — — — — — 
 Fronton BV, Common Stock 1.4 — — — (0.4)1.0 — — — — 
 Micronics Filtration Holdings Inc, Common Stock — — (0.1)(0.5)0.6 — — — — — 
 Micronics Filtration Holdings Inc, Preferred Stock, Series A 0.1 — — (0.6)0.5 — — — — — 
 Micronics Filtration Holdings Inc, Preferred Stock, Series B 0.4 — (0.4)0.2 (0.2)— — — — — 
 Micronics Filtration Holdings Inc, Preferred Stock, Series B PIK 11.9 — (11.9)11.9 (11.9)— — — — — 
 Micronics Filtration Holdings Inc, Preferred Stock, Series C PIK 6.2 — (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 Units 0.1 0.1 — — 0.9 1.1 — — — — 
 Proserv Acquisition LLC, Class A Preferred Units 9.3 — — — 0.2 9.5 — — — — 
 Sorenson Communications LLC, Common Stock(4)
67.5 — (65.4)22.9 (25.0)— — — — — 
 Sungard Availbaility 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 and other 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.
[42] 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, 2021, 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 December 31, 2021:
Portfolio CompanyFair Value at December 31, 2020
Gross Additions(1)
Gross Reductions(2)
Net Realized Gain (Loss)Net Change in Unrealized Appreciation (Depreciation)Fair Value at December 31, 2021
Interest Income(3)
PIK Income(3)
Fee Income(3)
Dividend Income(3)
Senior Secured Loans—First Lien
Portfolio CompanyFair Value at December 31, 2020
Gross Additions(1)
Gross Reductions(2)
Net Realized Gain (Loss)Net Change in Unrealized Appreciation (Depreciation)Fair Value at December 31, 2021
Interest Income(3)
PIK Income(3)
Fee Income(3)
Dividend Income(3)
Affordable Care Inc$ $— $— $— $— $— $— $— $0.3 $— 
Affordable Care Inc— 115.5 (55.9)0.3 — 59.9 2.7 — 1.6 — 
Belk Inc— 42.6 (2.4)— 9.0 49.2 3.1 0.9 — — 
Belk Inc— 21.7 — — 0.2 21.9 1.6 — — — 
Borden (New Dairy Opco)7.6 10.6 (10.0)0.2 0.6 9.0 0.5 — — — 
Borden (New Dairy Opco)16.8 23.4 — — 1.8 42.0 2.7 — — — 
Borden Dairy Co— — — 1.3 (1.3)— — — — — 
Constellis Holdings LLC— 14.0 — — 1.0 15.0 0.9 — — — 
Fairway Group Holdings Corp— 1.1 (0.7)0.6 (0.3)0.7 0.8 — — — 
Fairway Group Holdings Corp— — — — — — — — — — 
 HM Dunn Co Inc(5)
0.3 — (0.6)— 0.3 — — — — — 
 HM Dunn Co Inc(5)
0.2 — (0.3)— 0.1 — — — — — 
Micronics Filtration Holdings Inc35.5 1.0 — — 14.5 51.0 — 1.0 — — 
 One Call Care Management Inc(5)
4.7 0.6 (4.9)— (0.4)— 0.2 — — — 
Petroplex Acidizing Inc4.5 — (0.2)— 5.4 9.7 — — — — 
 Sorenson Communications LLC(4)
— 61.8 (5.1)0.2 3.2 60.1 2.8 — — — 
 Sungard Availability Services Capital Inc(4)
— 5.7 — — 0.3 6.0 0.2 0.1 — — 
ThermaSys Corp3.9 0.4 — — (0.8)3.5 — 0.5 — — 
Senior Secured Loans—Second Lien
Belk Inc— 4.2 — — 2.5 6.7 — — — — 
Constellis Holdings LLC— 12.5 — — (0.5)12.0 0.6 0.4 — — 
Fairway Group Holdings Corp— — — — — — — — — — 
Sorenson Communications LLC— 22.0 (22.2)0.2 — — 0.4 0.9 — — 
Sungard Availability Services Capital Inc— 13.6 0.1 — (5.4)8.3 0.7 0.2 — — 
Other Senior Secured Debt
JW Aluminum Co(5)
41.8 — (39.4)— (2.4)— — — — — 
Subordinated Debt
Home Partners of America Inc— 3.5 (3.5)— — — 0.1 — — — 
Asset Based Finance
Home Partners JV, Structured Mezzanine38.5 83.4 (36.3)— 4.8 90.4 0.6 7.3 — — 
Home Partners JV, Private Equity— 5.4 — — 4.0 9.4 — — — — 
Home Partners JV, Private Equity— — — (0.6)0.6 — — — — — 
Home Partners JV, Common Stock21.5 45.9 (22.9)7.7 28.4 80.6 — — — — 
Home Partners JV 2, Structured Mezzanine— 3.4 — — 0.1 3.5 — 0.2 — — 
Home Partners JV 2, Private Equity— 0.1 — — — 0.1 — — — — 
Home Partners JV 2, Private Equity— 1.5 — — 0.1 1.6 — — — — 
Jet Edge International LLC, Preferred Stock— 20.9 — — (4.1)16.8 0.5 — — — 
Portfolio CompanyFair Value at December 31, 2020
Gross Additions(1)
Gross Reductions(2)
Net Realized Gain (Loss)Net Change in Unrealized Appreciation (Depreciation)Fair Value at December 31, 2021
Interest Income(3)
PIK Income(3)
Fee Income(3)
Dividend Income(3)
Jet Edge International LLC, Warrant— — — — 4.5 4.5 — — — — 
Jet Edge International LLC, Term Loan— 78.0 (2.1)— (0.3)75.6 2.4 0.5 — — 
Orchard Marine Limited, Class B Common Stock— — — — — — — — — — 
Orchard Marine Limited, Series A Preferred Stock24.6 — — — 40.0 64.6 — — — — 
Equity/Other
Affordable Care Inc, Common Stock— 48.1 — — 4.0 52.1 — 2.3 — — 
ASG Technologies, Common Stock42.7 — (79.4)56.0 (19.3)— — — — — 
ASG Technologies, Warrants3.5 — (10.2)3.7 3.0 — — — — — 
Belk Inc, Common Stock— — — — — — — — — — 
Borden (New Dairy Opco), Common Stock3.2 5.2 — — (0.7)7.7 — — — — 
Charlotte Russe Inc, Common Stock— — — (12.5)12.5 — — — — — 
Constellis Holdings LLC, Private Equity— 10.3 — — (10.1)0.2 — — — — 
Fairway Group Holdings Corp, Common Stock— — — — — — — — — — 
Fronton BV, Common Stock1.2 — — — 0.2 1.4 — — — — 
 HM Dunn Co Inc, Preferred Stock, Series A(5)
— — — — — — — — — — 
 HM Dunn Co Inc, Preferred Stock, Series B(5)
— — — — — — — — — — 
Home Partners of America Inc, Common Stock130.5 — (214.3)130.7 (46.9)— — — — — 
Home Partners of America Inc, Warrant2.1 — (4.4)4.1 (1.8)— — — — — 
 JW Aluminum Co, Common Stock(5)
— — — — — — — — — — 
 JW Aluminum Co, Preferred Stock(5)
93.7 — (107.3)— 13.6 — — 4.2 — — 
Micronics Filtration Holdings Inc, Common Stock— — — — — — — — — — 
Micronics Filtration Holdings Inc, Preferred Stock, Series A— — — — 0.1 0.1 — — — — 
Micronics Filtration Holdings Inc, Preferred Stock, Series B— — — — 0.4 0.4 — — — — 
Micronics Filtration Holdings Inc, Preferred Stock, Series B PIK— — — — 11.9 11.9 — — — — 
Micronics Filtration Holdings Inc, Preferred Stock, Series C PIK— — — — 6.2 6.2 — — — — 
 One Call Care Management Inc, Common Stock(5)
2.4 — (3.0)— 0.6 — — — — — 
 One Call Care Management Inc, Preferred Stock A(5)
25.5 — (32.3)— 6.8 — — — — — 
 One Call Care Management Inc, Preferred Stock B(5)
10.6 — (9.8)— (0.8)— — — — — 
Petroplex Acidizing Inc, Preferred Stock A— 0.4 — — (0.4)— — — — 0.4 
Petroplex Acidizing Inc, Warrant— — — — — — — — — — 
Proserv Acquisition LLC, Class A Common Units9.0 — (0.1)— (8.8)0.1 — — — — 
Proserv Acquisition LLC, Class A Preferred Units9.5 — — — (0.2)9.3 — — — — 
 Sorenson Communications LLC, Common Stock(4)
— 42.5 — — 25.0 67.5 — — — — 
Sungard Availability Services Capital Inc, Common Stock(4)
— 6.9 — — (6.9)— — — — — 
ThermaSys Corp, Common Stock— — — — — — — — — — 
ThermaSys Corp, Preferred Stock— — — — — — — — — — 
Total$533.8 $706.2 $(667.2)$191.9 $94.3 $859.0 $20.8 $18.5 $1.9 $0.4 
[43] 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).
[44] Security or portion thereof was held within CCT Dublin Funding Limited
[45] Security or portion thereof was held within CCT Dublin Funding Limited
[46] Security held within CCT Holdings II, LLC, a wholly-owned subsidiary of the Company.
[47] Security held within CCT Holdings II, LLC, a wholly-owned subsidiary of the Company.
[48] Security held within IC American Energy Investments, Inc., 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 FSIC II 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 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).
[53] 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).
[54] 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).
[55] Security held within FSIC Investments, Inc., a wholly-owned subsidiary of the Company.
[56] Security held within FSIC Investments, Inc., a wholly-owned subsidiary of the Company.
[57] The Company held this investment as of December 31, 2020 but it was not deemed to be an “control” of the portfolio company as of December 31, 2020. Transfers in or out have been presented at amortized cost.
[58] The Company held this investment as of December 31, 2021 but it was deemed to "control" the portfolio company as of December 31, 2021. Transfers in or out have been presented at amortized cost.
[59] 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.(5)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 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.
[61] 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.
[62] The Company held this investment as of December 31, 2020 but it was not deemed to be an “affiliated person” of the portfolio company as of December 31, 2020. Transfers in or out have been presented at amortized cost.