Quarterly report pursuant to Section 13 or 15(d)

Consolidated Schedule of Investments (Parenthetical)

v3.22.2.2
Consolidated Schedule of Investments (Parenthetical) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2022
Sep. 30, 2021
Sep. 30, 2022
Sep. 30, 2021
Dec. 31, 2021
Schedule of Investments [Line Items]          
Unrealized gain (loss) for U.S. federal income tax purposes         $ (36,800)
Net change in unrealized gain (loss)     $ (115,913) $ 134,328  
Cost for income tax purposes $ 13,000,000   13,000,000   12,800,000
Unrealized loss for U.S. federal income tax purposes         217,600
Unrealized gain for U.S. federal income tax purposes         180,800
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [1],[2],[3]     12,741,640    
Net change in unrealized gain (loss)     (115,913) 134,328  
Ending balance 12,835,918 [4],[5],[6]   12,835,918 [4],[5],[6]   12,741,640 [1],[2],[3]
Restricted investments, fair value $ 1,500,000   $ 1,500,000   $ 1,100,000
Restricted investments as a percentage of net assets 25.40%   25.40%   18.30%
Non-qualifying assets as a percent of total assets 13.50%   13.50%   9.90%
Non-qualifying asset, fair value $ 7,700   $ 7,700   $ 8,000
Non-controlled, affiliated investments          
Schedule of Investments [Line Items]          
Net change in unrealized gain (loss) 0 $ 0 0 0  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     0    
Gross Additions [7]     7,032    
Gross Reductions [8]     0    
Net change in unrealized gain (loss) 0 0 0 0  
Ending balance 7,032   7,032   0
Interest income     0    
Dividend income     0    
Other income     0    
Investment income from controlled, affiliated investments:          
Schedule of Investments [Line Items]          
Net change in unrealized gain (loss) 47,026 985 31,632 367 44,081
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     616,780 272,381 272,381
Gross Additions     315,864 [9]   474,436 [10]
Gross Reductions     (57,882) [11]   (174,119) [12]
Net change in unrealized gain (loss) 47,026 985 31,632 367 44,081
Ending balance 906,394   906,394   616,780
Interest income     5,767   5,531
Dividend income 20,303 7,128 59,136 13,469 20,394
Other income $ 195 $ 163 $ 520 480 $ 643
Investment, Identifier [Axis]: 3ES Innovation Inc. (dba Aucerna), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.75% [13],[14],[15],[16]   6.75% [13],[14],[15],[16]   6.75% [17],[18],[19],[20]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19],[20]     $ 60,340    
Ending balance $ 60,183 [13],[14],[15],[16]   $ 60,183 [13],[14],[15],[16]   $ 60,340 [17],[18],[19],[20]
Investment, Identifier [Axis]: 3ES Innovation Inc. (dba Aucerna), First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.75% [13],[14],[15],[16],[21]   6.75% [13],[14],[15],[16],[21]   6.75% [17],[18],[20],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[20],[22],[23]     $ (58)    
Ending balance $ 1,661 [13],[14],[15],[16],[21]   1,661 [13],[14],[15],[16],[21]   $ (58) [17],[18],[20],[22],[23]
Investment, Identifier [Axis]: AAM Series 1.1 Rail and Domestic Intermodal Feeder, LLC | Investment income from controlled, affiliated investments:          
Schedule of Investments [Line Items]          
Net change in unrealized gain (loss)     (5)    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     0    
Gross Additions     5    
Gross Reductions     0    
Net change in unrealized gain (loss)     (5)    
Ending balance 0   0   0
Interest income     0    
Dividend income     0    
Other income     0    
Investment, Identifier [Axis]: AAM Series 1.1 Rail and Domestic Intermodal Feeder, LLC, LLC Interest          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [14],[16],[21],[24],[25],[26] 0   0    
Investment, Identifier [Axis]: AAM Series 2.1 Aviation Feeder, LLC | Investment income from controlled, affiliated investments:          
Schedule of Investments [Line Items]          
Net change in unrealized gain (loss)     (5)    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     0    
Gross Additions     1,373    
Gross Reductions     0    
Net change in unrealized gain (loss)     (5)    
Ending balance 1,368   1,368   $ 0
Interest income     0    
Dividend income     0    
Other income     0    
Investment, Identifier [Axis]: AAM Series 2.1 Aviation Feeder, LLC, LLC Interest          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [14],[16],[21],[24],[25],[26] $ 1,368   1,368    
Investment, Identifier [Axis]: ABB/Con-cise Optical Group LLC, Second lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[27]         9.00%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[27]     $ 24,875    
Ending balance [17],[27]         $ 24,875
Investment, Identifier [Axis]: ABB/Con-cise Optical Group LLC, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 7.50% [13],[14],[15]   7.50% [13],[14],[15]   5.00% [17],[27]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[27]     $ 74,456    
Ending balance $ 67,416 [13],[14],[15]   $ 67,416 [13],[14],[15]   $ 74,456 [17],[27]
Investment, Identifier [Axis]: ABB/Con-cise Optical Group LLC, First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[15],[21] 7.50%   7.50%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[15],[21] $ 6,562   $ 6,562    
Investment, Identifier [Axis]: ASP Conair Holdings LP, Class A Units          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [18],[28],[29]     6,071    
Ending balance $ 5,480 [14],[25],[26]   $ 5,480 [14],[25],[26]   $ 6,071 [18],[28],[29]
Investment, Identifier [Axis]: Accela, Inc., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 7.50% [13],[30]   7.50% [13],[30]   7.50% [17],[27]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[27]     $ 23,990    
Ending balance $ 24,291 [13],[30]   $ 24,291 [13],[30]   $ 23,990 [17],[27]
Investment, Identifier [Axis]: Accela, Inc., First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 7.00% [13],[21],[30]   7.00% [13],[21],[30]   7.00% [17],[22]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[22]     $ 0    
Ending balance $ 1,463 [13],[21],[30]   1,463 [13],[21],[30]   $ 0 [17],[22]
Investment, Identifier [Axis]: Accelerate topco Holdings, LLC, Common Units          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [14],[25],[26] $ 14   $ 14    
Investment, Identifier [Axis]: Access CIG, LLC, Second lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 7.75% [13],[14],[15]   7.75% [13],[14],[15]   7.75% [17],[18],[27]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[27]     $ 58,466    
Ending balance $ 58,024 [13],[14],[15]   58,024 [13],[14],[15]   $ 58,466 [17],[18],[27]
Investment, Identifier [Axis]: Alera Group, Inc., First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[22],[27],[31]         5.50%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[27],[31]     $ 11,554    
Ending balance [17],[18],[22],[27],[31]         $ 11,554
Investment, Identifier [Axis]: Alera Group, Inc., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.50% [13],[14],[32]   6.50% [13],[14],[32]   5.50% [17],[18],[27]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[27]     $ 42,068    
Ending balance $ 34,640 [13],[14],[32]   $ 34,640 [13],[14],[32]   $ 42,068 [17],[18],[27]
Investment, Identifier [Axis]: AmSpec Group, Inc. (fka AmSpec Services Inc.), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.75% [13],[14],[15]   5.75% [13],[14],[15]   5.75% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 109,713    
Ending balance $ 108,589 [13],[14],[15]   $ 108,589 [13],[14],[15]   $ 109,713 [17],[18],[19]
Investment, Identifier [Axis]: AmSpec Group, Inc. (fka AmSpec Services Inc.), First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 3.75% [13],[14],[21],[33]   3.75% [13],[14],[21],[33]   3.75% [17],[18],[22],[34]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[34]     $ 3,724    
Ending balance $ 2,603 [13],[14],[21],[33]   2,603 [13],[14],[21],[33]   $ 3,724 [17],[18],[22],[34]
Investment, Identifier [Axis]: Amergin Asset Management, LLC, Class A Units          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [14],[16],[25],[26] $ 0   $ 0    
Investment, Identifier [Axis]: AmeriLife Holdings LLC, First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[21],[35],[36] 5.75%   5.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[21],[35],[36] $ (4)   $ (4)    
Investment, Identifier [Axis]: AmeriLife Holdings LLC, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[32] 5.75%   5.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[32] $ 713   $ 713    
Investment, Identifier [Axis]: AmeriLife Holdings LLC, First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[21],[35] 5.75%   5.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[21],[35] $ (1)   $ (1)    
Investment, Identifier [Axis]: Anaplan, Inc., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[37] 6.50%   6.50%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[37] $ 134,744   $ 134,744    
Investment, Identifier [Axis]: Anaplan, Inc., First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[21],[35] 6.50%   6.50%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[21],[35] $ (24)   $ (24)    
Investment, Identifier [Axis]: Apex Group Treasury, LLC, Second lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[20],[22],[31]         6.75%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[20],[22],[31]     $ 0    
Ending balance [17],[18],[20],[22],[31]         $ 0
Investment, Identifier [Axis]: Apex Group Treasury, LLC, Second lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.75% [13],[14],[15],[16]   6.75% [13],[14],[15],[16]   6.75% [17],[18],[19],[20]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19],[20]     $ 18,810    
Ending balance $ 42,381 [13],[14],[15],[16]   $ 42,381 [13],[14],[15],[16]   $ 18,810 [17],[18],[19],[20]
Investment, Identifier [Axis]: Apex Service Partners Intermediate 2, LLC, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [14],[23] 12.50%   12.50%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [14],[23] $ 46,313   $ 46,313    
Investment, Identifier [Axis]: Apex Service Partners, LLC, First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[21],[32],[36] 5.50%   5.50%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[21],[32],[36] $ 826   $ 826    
Investment, Identifier [Axis]: Apex Service Partners, LLC, First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[21],[35] 5.50%   5.50%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[21],[35] $ 0   $ 0    
Investment, Identifier [Axis]: Apptio, Inc., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.00% [13],[14],[15]   6.00% [13],[14],[15]   7.25% [17],[18]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[38]     $ 50,916    
Ending balance $ 50,916 [13],[14],[15]   $ 50,916 [13],[14],[15]   $ 50,916 [17],[18],[38]
Investment, Identifier [Axis]: Apptio, Inc., First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.00% [13],[14],[15],[21]   6.00% [13],[14],[15],[21]   7.25% [17],[18],[19],[22]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19],[22]     $ 1,112    
Ending balance $ 1,112 [13],[14],[15],[21]   $ 1,112 [13],[14],[15],[21]   $ 1,112 [17],[18],[19],[22]
Investment, Identifier [Axis]: Aptive Environmental, LLC, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [14],[39] 12.00%   12.00%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [14],[39] $ 10,268   $ 10,268    
Investment, Identifier [Axis]: Aramsco, Inc., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.25% [13],[14],[30]   5.25% [13],[14],[30]   5.25% [17],[18],[27]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[27]     $ 55,899    
Ending balance $ 55,327 [13],[14],[30]   $ 55,327 [13],[14],[30]   $ 55,899 [17],[18],[27]
Investment, Identifier [Axis]: Aramsco, Inc., First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.25% [13],[14],[21],[30]   5.25% [13],[14],[21],[30]   5.25% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ 0    
Ending balance $ 258 [13],[14],[21],[30]   $ 258 [13],[14],[21],[30]   $ 0 [17],[18],[22],[23]
Investment, Identifier [Axis]: Ardonagh Midco 2 PLC, Unsecured notes          
Schedule of Investments [Line Items]          
Basis spread, variable rate [14],[16],[39] 11.50%   11.50%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [18],[20],[40]     $ 11,620    
Ending balance $ 11,030 [14],[16],[39]   $ 11,030 [14],[16],[39]   $ 11,620 [18],[20],[40]
Investment, Identifier [Axis]: Ardonagh Midco 3 PLC, First lien senior secured EUR term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[16],[41] 7.00%   7.00%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[16],[41] $ 8,926   $ 8,926    
Investment, Identifier [Axis]: Ardonagh Midco 3 PLC, First lien senior secured GBP delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.75% [13],[14],[16],[21],[35],[36]   5.75% [13],[14],[16],[21],[35],[36]   5.50% [17],[18],[20],[22],[31]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[20],[22],[31]     $ 0    
Ending balance $ (68) [13],[14],[16],[21],[35],[36]   $ (68) [13],[14],[16],[21],[35],[36]   $ 0 [17],[18],[20],[22],[31]
Investment, Identifier [Axis]: Ardonagh Midco 3 PLC, First lien senior secured GBP term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 7.00% [13],[14],[16],[38]   7.00% [13],[14],[16],[38]   6.75% [17],[18],[20],[42]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[20],[42]     $ 117,374    
Ending balance $ 96,736 [13],[14],[16],[38]   96,736 [13],[14],[16],[38]   $ 117,374 [17],[18],[20],[42]
Investment, Identifier [Axis]: Ardonagh Midco 3 PLC, First lien senior secured USD delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[20]         5.50%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[20],[38]     $ 26,784    
Ending balance [17],[18],[20],[38]         $ 26,784
Investment, Identifier [Axis]: Ardonagh Midco 3 PLC, First lien senior secured USD term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[16],[38] 5.75%   5.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[16],[38] $ 26,583   $ 26,583    
Investment, Identifier [Axis]: Ardonagh Midco 3 PLC, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[20],[43]         6.75%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[20],[43]     $ 10,388    
Ending balance [17],[18],[20],[43]         $ 10,388
Investment, Identifier [Axis]: Armstrong Bidco Limited (dba The Access Group), First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[16],[21],[36],[39] 5.75%   5.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[16],[21],[36],[39] $ 368   $ 368    
Investment, Identifier [Axis]: Armstrong Bidco Limited (dba The Access Group), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[16],[39] 5.75%   5.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[16],[39] $ 2,139   $ 2,139    
Investment, Identifier [Axis]: Aruba Investments Holdings LLC (dba Angus Chemical Company),Second lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[38]         7.75%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[38]     $ 10,000    
Ending balance [17],[18],[38]         $ 10,000
Investment, Identifier [Axis]: Aruba Investments Holdings, LLC (dba Angus Chemical Company), Second lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[30] 7.75%   7.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[30] $ 9,725   $ 9,725    
Investment, Identifier [Axis]: Ascend Buyer, LLC (dba PPC Flexible Packaging), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.75% [13],[14],[15]   5.75% [13],[14],[15]   5.75% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 5,498    
Ending balance $ 5,443 [13],[14],[15]   $ 5,443 [13],[14],[15]   $ 5,498 [17],[18],[19]
Investment, Identifier [Axis]: Ascend Buyer, LLC (dba PPC Flexible Packaging), First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.75% [13],[14],[21],[30]   5.75% [13],[14],[21],[30]   5.75% [17],[18],[19],[22]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19],[22]     $ 88    
Ending balance $ 68 [13],[14],[21],[30]   $ 68 [13],[14],[21],[30]   $ 88 [17],[18],[19],[22]
Investment, Identifier [Axis]: Associations Finance, Inc., Preferred Stock          
Schedule of Investments [Line Items]          
Basis spread, variable rate [14],[23],[26] 12.00%   12.00%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [14],[23],[26] $ 54,020   $ 54,020    
Investment, Identifier [Axis]: Associations, Inc., First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[21],[32],[36] 6.50%   6.50%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[21],[32],[36] $ 2,796   $ 2,796    
Investment, Identifier [Axis]: Associations, Inc., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.50% [13],[14],[32]   6.50% [13],[14],[32]   6.50% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 448,102    
Ending balance $ 382,833 [13],[14],[32]   $ 382,833 [13],[14],[32]   $ 448,102 [17],[18],[19]
Investment, Identifier [Axis]: Associations, Inc., First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.50% [13],[14],[21],[35]   6.50% [13],[14],[21],[35]   6.50% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ (329)    
Ending balance $ (82) [13],[14],[21],[35]   $ (82) [13],[14],[21],[35]   $ (329) [17],[18],[22],[23]
Investment, Identifier [Axis]: Aviation Solutions Midco, LLC (dba STS Aviation), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 7.25% [13],[14],[15]   7.25% [13],[14],[15]   7.25% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 202,838    
Ending balance $ 205,709 [13],[14],[15]   $ 205,709 [13],[14],[15]   $ 202,838 [17],[18],[19]
Investment, Identifier [Axis]: AxiomSL Group, Inc., First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.00% [13],[14],[21],[35],[36]   6.00% [13],[14],[21],[35],[36]   6.00% [17],[18],[22],[23],[31]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23],[31]     $ 0    
Ending balance $ (62) [13],[14],[21],[35],[36]   $ (62) [13],[14],[21],[35],[36]   $ 0 [17],[18],[22],[23],[31]
Investment, Identifier [Axis]: AxiomSL Group, Inc., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.00% [13],[14],[30]   6.00% [13],[14],[30]   6.00% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 201,254    
Ending balance $ 197,725 [13],[14],[30]   $ 197,725 [13],[14],[30]   $ 201,254 [17],[18],[19]
Investment, Identifier [Axis]: AxiomSL Group, Inc., First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.00% [13],[14],[21],[35]   6.00% [13],[14],[21],[35]   6.00% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ (137)    
Ending balance $ (319) [13],[14],[21],[35]   $ (319) [13],[14],[21],[35]   $ (137) [17],[18],[22],[23]
Investment, Identifier [Axis]: BCPE Nucleon (DE) SPV, LP, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [38] 7.00% [13],[14]   7.00% [13],[14]   7.00% [17],[18]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[38]     $ 188,829    
Ending balance [38] $ 188,829 [13],[14]   $ 188,829 [13],[14]   $ 188,829 [17],[18]
Investment, Identifier [Axis]: BCPE Osprey Buyer, Inc. (dba PartsSource), First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.75% [13],[14],[21],[35],[36]   5.75% [13],[14],[21],[35],[36]   5.75% [17],[18],[22],[23],[31]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23],[31]     $ (133)    
Ending balance $ (315) [13],[14],[21],[35],[36]   $ (315) [13],[14],[21],[35],[36]   $ (133) [17],[18],[22],[23],[31]
Investment, Identifier [Axis]: BCPE Osprey Buyer, Inc. (dba PartsSource), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.75% [13],[14],[15]   5.75% [13],[14],[15]   5.75% [17],[18]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[38]     $ 112,227    
Ending balance $ 110,649 [13],[14],[15]   $ 110,649 [13],[14],[15]   $ 112,227 [17],[18],[38]
Investment, Identifier [Axis]: BCPE Osprey Buyer, Inc. (dba PartsSource), First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.75% [13],[14],[21],[35]   5.75% [13],[14],[21],[35]   5.75% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ (190)    
Ending balance $ (267) [13],[14],[21],[35]   $ (267) [13],[14],[21],[35]   $ (190) [17],[18],[22],[23]
Investment, Identifier [Axis]: BCPE Watson (DE) ORML, LP, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[16],[44],[45] 6.50%   6.50%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[16],[44],[45] $ 14,850   $ 14,850    
Investment, Identifier [Axis]: BCTO BSI Buyer, Inc. (dba Buildertrend), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 8.00% [13],[14],[32]   8.00% [13],[14],[32]   7.00% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 44,420    
Ending balance $ 51,889 [13],[14],[32]   $ 51,889 [13],[14],[32]   $ 44,420 [17],[18],[19]
Investment, Identifier [Axis]: BCTO BSI Buyer, Inc. (dba Buildertrend), First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 7.00% [13],[14],[21],[35]   7.00% [13],[14],[21],[35]   7.00% [17],[18],[19],[22]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19],[22]     $ 2,991    
Ending balance $ 0 [13],[14],[21],[35]   0 [13],[14],[21],[35]   $ 2,991 [17],[18],[19],[22]
Investment, Identifier [Axis]: BCTO WIW Holdings, Inc. (dba When I Work), Class A Common Stock          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [18],[28],[29]     1,300    
Ending balance 1,171 [14],[25],[26]   1,171 [14],[25],[26]   $ 1,300 [18],[28],[29]
Investment, Identifier [Axis]: BEHP Co-Investor II, L.P., Common Equity          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [14],[16],[25],[26] $ 1,270   $ 1,270    
Investment, Identifier [Axis]: BP Veraison Buyer, LLC (dba Sun World), First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.75% [13],[14],[21],[35],[36]   5.75% [13],[14],[21],[35],[36]   5.75% [17],[18],[22],[23],[31]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23],[31]     $ 0    
Ending balance $ 0 [13],[14],[21],[35],[36]   $ 0 [13],[14],[21],[35],[36]   $ 0 [17],[18],[22],[23],[31]
Investment, Identifier [Axis]: BP Veraison Buyer, LLC (dba Sun World), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.75% [13],[14],[15]   5.75% [13],[14],[15]   5.75% [17],[18],[46]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[46]     $ 68,687    
Ending balance $ 68,342 [13],[14],[15]   $ 68,342 [13],[14],[15]   $ 68,687 [17],[18],[46]
Investment, Identifier [Axis]: BP Veraison Buyer, LLC (dba Sun World), First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.75% [13],[14],[21],[35]   5.75% [13],[14],[21],[35]   5.75% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ (87)    
Ending balance $ (65) [13],[14],[21],[35]   (65) [13],[14],[21],[35]   $ (87) [17],[18],[22],[23]
Investment, Identifier [Axis]: Balrog Acquisition, Inc. (dba BakeMark), Second lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[38]         7.00%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[38]     $ 21,815    
Ending balance [17],[18],[38]         $ 21,815
Investment, Identifier [Axis]: Balrog Acquisition, Inc. (dba Bakemark), Second lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[15] 7.00%   7.00%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[15] $ 21,560   $ 21,560    
Investment, Identifier [Axis]: Bayshore Intermediate #2, L.P. (dba Boomi), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[30] 7.75%   7.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 81,095    
Ending balance $ 88,099 [13],[14],[30]   $ 88,099 [13],[14],[30]   $ 81,095 [17],[18],[19]
Investment, Identifier [Axis]: Bayshore Intermediate #2, L.P. (dba Boomi), First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.75% [13],[14],[21],[35]   6.75% [13],[14],[21],[35]   6.75% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ (156)    
Ending balance $ (156) [13],[14],[21],[35]   (156) [13],[14],[21],[35]   $ (156) [17],[18],[22],[23]
Investment, Identifier [Axis]: Black Mountain Sand Eagle Ford LLC, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[19]         8.25%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 4,808    
Ending balance [17],[18],[19]         $ 4,808
Investment, Identifier [Axis]: Blackhawk Network Holdings, Inc., Second lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 7.00% [13],[14],[15]   7.00% [13],[14],[15]   7.00% [17],[18],[27]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[27]     $ 106,400    
Ending balance $ 105,868 [13],[14],[15]   105,868 [13],[14],[15]   $ 106,400 [17],[18],[27]
Investment, Identifier [Axis]: Blend Labs, Inc., Common Stock          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [18],[28],[29]     515    
Ending balance [18],[28],[29]         $ 515
Investment, Identifier [Axis]: Blend Labs, Inc., Common stock          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [14],[25],[47] $ 160   $ 160    
Investment, Identifier [Axis]: Blend Labs, Inc., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 7.50% [13],[14],[30]   7.50% [13],[14],[30]   7.50% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 66,150    
Ending balance $ 66,319 [13],[14],[30]   $ 66,319 [13],[14],[30]   $ 66,150 [17],[18],[19]
Investment, Identifier [Axis]: Blend Labs, Inc., First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 7.50% [13],[14],[21],[35]   7.50% [13],[14],[21],[35]   7.50% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ (150)    
Ending balance $ (131) [13],[14],[21],[35]   (131) [13],[14],[21],[35]   $ (150) [17],[18],[22],[23]
Investment, Identifier [Axis]: Blend Labs, Inc., Warrants          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [18],[28],[29]     380    
Ending balance $ 22 [14],[25],[26]   $ 22 [14],[25],[26]   $ 380 [18],[28],[29]
Investment, Identifier [Axis]: Bracket Intermediate Holding Corp., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 4.25% [13],[14],[15],[48]   4.25% [13],[14],[15],[48]   4.25% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 514    
Ending balance $ 485 [13],[14],[15],[48]   $ 485 [13],[14],[15],[48]   $ 514 [17],[18],[19]
Investment, Identifier [Axis]: Bracket Intermediate Holding Corp., Second lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 8.13% [13],[14],[15]   8.13% [13],[14],[15]   8.13% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 26,119    
Ending balance $ 25,134 [13],[14],[15]   $ 25,134 [13],[14],[15]   $ 26,119 [17],[18],[19]
Investment, Identifier [Axis]: Brightway Holdings, LLC, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.50% [13],[14],[30]   6.50% [13],[14],[30]   6.50% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 26,507    
Ending balance $ 26,174 [13],[14],[30]   $ 26,174 [13],[14],[30]   $ 26,507 [17],[18],[19]
Investment, Identifier [Axis]: Brightway Holdings, LLC, First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.50% [13],[21],[35]   6.50% [13],[21],[35]   6.50% [17],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[22],[23]     $ (39)    
Ending balance $ (63) [13],[21],[35]   (63) [13],[21],[35]   $ (39) [17],[22],[23]
Investment, Identifier [Axis]: Brooklyn Lender Co-Invest 2, L.P. (dba Boomi), Common Units          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [14],[25],[26] 7,379   7,379    
Investment, Identifier [Axis]: Brooklyn Lender Co-Invest 2, L.P., Common Units          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [18],[28],[29]     7,504    
Ending balance [18],[28],[29]         7,504
Investment, Identifier [Axis]: CD&R Value Building Partners I, L.P. (dba Belron), LP Interest          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [14],[16],[25],[26] $ 32,614   32,614    
Investment, Identifier [Axis]: CD&R Value Building Partners I, L.P., LP Interest          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [18],[20],[28],[29]     $ 33,000    
Ending balance [18],[20],[28],[29]         $ 33,000
Investment, Identifier [Axis]: CIBT Global, Inc., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.25% [13],[14],[15],[49]   5.25% [13],[14],[15],[49]   5.25% [17],[18],[19],[50]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19],[50]     $ 531    
Ending balance $ 507 [13],[14],[15],[49]   $ 507 [13],[14],[15],[49]   $ 531 [17],[18],[19],[50]
Investment, Identifier [Axis]: CIBT Global, Inc., Second lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 7.75% [13],[14],[15],[49]   7.75% [13],[14],[15],[49]   7.75% [17],[18],[50],[51]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[50],[51]     $ 15,919    
Ending balance $ 10,506 [13],[14],[15],[49]   $ 10,506 [13],[14],[15],[49]   $ 15,919 [17],[18],[50],[51]
Investment, Identifier [Axis]: CP PIK DEBT ISSUER, LLC (dba CivicPlus, LLC), Unsecured notes          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[45] 11.75%   11.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[45] $ 16,399   $ 16,399    
Investment, Identifier [Axis]: CSC MKG Topco LLC. (dba Medical Knowledge Group), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[30] 5.75%   5.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[30] $ 1,246   $ 1,246    
Investment, Identifier [Axis]: Centrify Corporation, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.00% [13],[14],[30]   6.00% [13],[14],[30]   5.75% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 65,564    
Ending balance $ 64,737 [13],[14],[30]   $ 64,737 [13],[14],[30]   $ 65,564 [17],[18],[19]
Investment, Identifier [Axis]: Centrify Corporation, First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.00% [13],[14],[21],[30]   6.00% [13],[14],[21],[30]   5.75% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ (136)    
Ending balance $ 3,238 [13],[14],[21],[30]   3,238 [13],[14],[21],[30]   $ (136) [17],[18],[22],[23]
Investment, Identifier [Axis]: Chapford SMA Partnership, L.P. | Non-controlled, affiliated investments          
Schedule of Investments [Line Items]          
Net change in unrealized gain (loss)     0    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     0    
Gross Additions     7,032    
Gross Reductions     0    
Net change in unrealized gain (loss)     0    
Ending balance 7,032   7,032   $ 0
Interest income     0    
Dividend income     0    
Other income     0    
Investment, Identifier [Axis]: Chapford SMA Partnership, L.P., LP Interest          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [14],[16],[21],[25],[26],[44],[52] $ 7,032   7,032    
Investment, Identifier [Axis]: CivicPlus, LLC, First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[22],[31]         6.00%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[31]     $ 0    
Ending balance [17],[18],[22],[31]         $ 0
Investment, Identifier [Axis]: CivicPlus, LLC, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.75% [13],[14],[30]   6.75% [13],[14],[30]   6.00% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 14,094    
Ending balance $ 34,460 [13],[14],[30]   $ 34,460 [13],[14],[30]   $ 14,094 [17],[18],[19]
Investment, Identifier [Axis]: CivicPlus, LLC, First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.25% [13],[14],[21],[35]   6.25% [13],[14],[21],[35]   6.00% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ (13)    
Ending balance $ (7) [13],[14],[21],[35]   $ (7) [13],[14],[21],[35]   $ (13) [17],[18],[22],[23]
Investment, Identifier [Axis]: ConAir Holdings LLC, Second lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 7.50% [13],[14],[15]   7.50% [13],[14],[15]   7.50% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 187,500    
Ending balance $ 170,625 [13],[14],[15]   $ 170,625 [13],[14],[15]   $ 187,500 [17],[18],[19]
Investment, Identifier [Axis]: Confluent Medical Technologies, Inc., Second lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[32] 6.50%   6.50%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[32] $ 985   $ 985    
Investment, Identifier [Axis]: Cornerstone OnDemand, Inc., Second lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.50% [13],[14],[30]   6.50% [13],[14],[30]   6.50% [17],[18],[38]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[38]     $ 114,096    
Ending balance $ 110,910 [13],[14],[30]   $ 110,910 [13],[14],[30]   $ 114,096 [17],[18],[38]
Investment, Identifier [Axis]: Delta TopCo, Inc. (dba Infoblox, Inc.), Second lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 7.25% [13],[14],[38]   7.25% [13],[14],[38]   7.25% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 15,000    
Ending balance $ 13,875 [13],[14],[38]   $ 13,875 [13],[14],[38]   $ 15,000 [17],[18],[19]
Investment, Identifier [Axis]: Denali BuyerCo, LLC (dba Summit Companies), First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.75% [13],[14],[15],[21],[36]   5.75% [13],[14],[15],[21],[36]   6.00% [18],[19],[22],[31]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19],[22],[31]     $ 1,983    
Ending balance $ 5,876 [13],[14],[15],[21],[36]   $ 5,876 [13],[14],[15],[21],[36]   $ 1,983 [17],[18],[19],[22],[31]
Investment, Identifier [Axis]: Denali BuyerCo, LLC (dba Summit Companies), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.75% [13],[14],[15]   5.75% [13],[14],[15]   6.00% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 50,879    
Ending balance $ 42,905 [13],[14],[15]   $ 42,905 [13],[14],[15]   $ 50,879 [17],[18],[19]
Investment, Identifier [Axis]: Denali BuyerCo, LLC (dba Summit Companies), First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.75% [13],[14],[21],[35]   5.75% [13],[14],[21],[35]   6.00% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ (36)    
Ending balance $ (37) [13],[14],[21],[35]   (37) [13],[14],[21],[35]   $ (36) [17],[18],[22],[23]
Investment, Identifier [Axis]: Denali Holding LP (dba Summit Companies), Class A Units          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [18],[28],[29]     3,136    
Ending balance [18],[28],[29]         $ 3,136
Investment, Identifier [Axis]: Denali Holding, LP (dba Summit Companies), Class A Units          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [14],[25],[26] $ 4,168   $ 4,168    
Investment, Identifier [Axis]: Diagnostic Service Holdings, Inc. (dba Rayus Radiology), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[30] 5.50%   5.50%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[30] $ 992   $ 992    
Investment, Identifier [Axis]: Diamondback Acquisition, Inc. (dba Sphera), First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.50% [13],[14],[21],[35],[36]   5.50% [13],[14],[21],[35],[36]   5.50% [17],[18],[22],[23],[31]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23],[31]     $ (11)    
Ending balance $ 0 [13],[14],[21],[35],[36]   $ 0 [13],[14],[21],[35],[36]   $ (11) [17],[18],[22],[23],[31]
Investment, Identifier [Axis]: Diamondback Acquisition, Inc. (dba Sphera), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.50% [13],[14],[30]   5.50% [13],[14],[30]   5.50% [17],[18],[27]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[27]     $ 5,298    
Ending balance $ 4,078 [13],[14],[30]   4,078 [13],[14],[30]   $ 5,298 [17],[18],[27]
Investment, Identifier [Axis]: Dodge Contruction Network Holdings, LP, Class A-2 Common Units          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [14],[25],[26] $ 1,855   $ 1,855    
Investment, Identifier [Axis]: Dodge Contruction Network Holdings, LP, Series A Preferred Units          
Schedule of Investments [Line Items]          
Basis spread, variable rate [14],[23],[26] 8.25%   8.25%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [14],[23],[26] $ 45   $ 45    
Investment, Identifier [Axis]: Dodge Data & Analytics LLC, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[19]         7.50%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     33,538    
Ending balance [17],[18],[19]         $ 33,538
Investment, Identifier [Axis]: Dodge Data & Analytics LLC, First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[22],[23]         7.50%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ 0    
Ending balance [17],[18],[22],[23]         $ 0
Investment, Identifier [Axis]: Douglas Products and Packaging Company LLC, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.75% [13],[14],[30]   5.75% [13],[14],[30]   5.75% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 105,117    
Ending balance $ 104,566 [13],[14],[30]   $ 104,566 [13],[14],[30]   $ 105,117 [17],[18],[19]
Investment, Identifier [Axis]: Douglas Products and Packaging Company LLC, First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 4.75% [13],[14],[21],[33]   4.75% [13],[14],[21],[33]   4.75% [17],[18],[22],[34]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[34]     $ 5,056    
Ending balance $ 6,159 [13],[14],[21],[33]   $ 6,159 [13],[14],[21],[33]   $ 5,056 [17],[18],[22],[34]
Investment, Identifier [Axis]: EET Buyer, Inc. (dba e-Emphasys), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.25% [13],[14],[15]   5.25% [13],[14],[15]   5.75% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 4,500    
Ending balance $ 4,466 [13],[14],[15]   $ 4,466 [13],[14],[15]   $ 4,500 [17],[18],[19]
Investment, Identifier [Axis]: EET Buyer, Inc. (dba e-Emphasys), First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.25% [13],[14],[21],[35]   5.25% [13],[14],[21],[35]   5.75% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ (5)    
Ending balance $ (6) [13],[14],[21],[35]   (6) [13],[14],[21],[35]   $ (5) [17],[18],[22],[23]
Investment, Identifier [Axis]: Elliott Alto Co-Investor Aggregator L.P., LP Interest          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [14],[16],[25],[26] $ 3,134   $ 3,134    
Investment, Identifier [Axis]: Endries Acquisition, Inc., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.25% [13],[14],[37]   6.25% [13],[14],[37]   6.25% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 200,163    
Ending balance $ 238,220 [13],[14],[37]   $ 238,220 [13],[14],[37]   $ 200,163 [17],[18],[19]
Investment, Identifier [Axis]: Engage Debtco Limited, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[16] 5.75%   5.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[16] $ 975   $ 975    
Investment, Identifier [Axis]: Entertainment Benefits Group, LLC, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 4.75% [13],[14],[37]   4.75% [13],[14],[37]   8.25% [17],[18]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[46]     $ 79,838    
Ending balance $ 862 [13],[14],[37]   $ 862 [13],[14],[37]   $ 79,838 [17],[18],[46]
Investment, Identifier [Axis]: Entertainment Benefits Group, LLC, First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 4.75% [13],[14],[21],[35]   4.75% [13],[14],[21],[35]   8.25% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ (504)    
Ending balance $ 0 [13],[14],[21],[35]   0 [13],[14],[21],[35]   $ (504) [17],[18],[22],[23]
Investment, Identifier [Axis]: Evology LLC, Class B Units          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [14],[25],[26] $ 2,160   $ 2,160    
Investment, Identifier [Axis]: Evolution BuyerCo, Inc. (dba SIAA), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.25% [13],[14],[15]   6.25% [13],[14],[15]   6.25% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 141,360    
Ending balance $ 139,588 [13],[14],[15]   $ 139,588 [13],[14],[15]   $ 141,360 [17],[18],[19]
Investment, Identifier [Axis]: Evolution BuyerCo, Inc. (dba SIAA), First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.25% [13],[14],[21],[35]   6.25% [13],[14],[21],[35]   6.25% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ (134)    
Ending balance $ (187) [13],[14],[21],[35]   (187) [13],[14],[21],[35]   $ (134) [17],[18],[22],[23]
Investment, Identifier [Axis]: Evolution Parent, LP (dba SIAA), LP Interest          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [18],[28],[29]     4,284    
Ending balance $ 4,284 [14],[25],[26]   $ 4,284 [14],[25],[26]   4,284 [18],[28],[29]
Investment, Identifier [Axis]: Ex Vivo Parent Inc. (dba OB Hospitalist), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[15] 9.50%   9.50%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 56,654    
Ending balance $ 56,798 [13],[14],[15]   $ 56,798 [13],[14],[15]   $ 56,654 [17],[18],[19]
Investment, Identifier [Axis]: FR Arsenal Holdings II Corp. (dba Applied-Cleveland Holdings, Inc.), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 9.50% [13],[30]   9.50% [13],[30]   7.50% [17],[38]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[38]     $ 112,932    
Ending balance $ 103,393 [13],[30]   $ 103,393 [13],[30]   $ 112,932 [17],[38]
Investment, Identifier [Axis]: Feradyne Outdoors, LLC, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.25% [13],[14],[30]   6.25% [13],[14],[30]   6.25% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 86,956    
Ending balance $ 85,659 [13],[14],[30]   $ 85,659 [13],[14],[30]   $ 86,956 [17],[18],[19]
Investment, Identifier [Axis]: Forescout Technologies, Inc., First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[21],[35],[36] 8.00%   8.00%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[21],[35],[36] $ 0   $ 0    
Investment, Identifier [Axis]: Forescout Technologies, Inc., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[15] 9.35%   9.35%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 54,811    
Ending balance $ 101,328 [13],[14],[15]   $ 101,328 [13],[14],[15]   $ 54,811 [17],[18],[19]
Investment, Identifier [Axis]: Forescout Technologies, Inc., First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 8.50% [13],[14],[21],[35]   8.50% [13],[14],[21],[35]   8.50% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ 0    
Ending balance $ 0 [13],[14],[21],[35]   $ 0 [13],[14],[21],[35]   $ 0 [17],[18],[22],[23]
Investment, Identifier [Axis]: Fortis Solutions Group, LLC, First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.50% [13],[14],[15],[21],[36]   5.50% [13],[14],[15],[21],[36]   5.50% [17],[18],[22],[23],[31]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23],[31]     $ (13)    
Ending balance $ 273 [13],[14],[15],[21],[36]   $ 273 [13],[14],[15],[21],[36]   $ (13) [17],[18],[22],[23],[31]
Investment, Identifier [Axis]: Fortis Solutions Group, LLC, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.50% [13],[14],[15]   5.50% [13],[14],[15]   5.50% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 3,257    
Ending balance $ 4,086 [13],[14],[15]   $ 4,086 [13],[14],[15]   $ 3,257 [17],[18],[19]
Investment, Identifier [Axis]: Fortis Solutions Group, LLC, First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.50% [13],[14],[21],[38]   5.50% [13],[14],[21],[38]   5.50% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ (9)    
Ending balance $ 18 [13],[14],[21],[38]   $ 18 [13],[14],[21],[38]   $ (9) [17],[18],[22],[23]
Investment, Identifier [Axis]: Foundation Consumer Brands, LLC, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[15] 5.50%   5.50%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[15] $ 3,511   $ 3,511    
Investment, Identifier [Axis]: Fullsteam Operations, LLC, First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[15],[21],[36] 8.78%   8.78%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[15],[21],[36] $ 3,086   $ 3,086    
Investment, Identifier [Axis]: GI Ranger Intermediate, LLC (dba Rectangle Health), First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[22],[23],[31]         6.00%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23],[31]     $ (6)    
Ending balance [17],[18],[22],[23],[31]         $ (6)
Investment, Identifier [Axis]: GI Ranger Intermediate, LLC (dba Rectangle Health), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.00% [13],[14],[32]   6.00% [13],[14],[32]   6.00% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 3,937    
Ending balance $ 4,481 [13],[14],[32]   $ 4,481 [13],[14],[32]   $ 3,937 [17],[18],[19]
Investment, Identifier [Axis]: GI Ranger Intermediate, LLC (dba Rectangle Health), First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.00% [13],[14],[21],[32]   6.00% [13],[14],[21],[32]   6.00% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ (7)    
Ending balance $ 28 [13],[14],[21],[32]   $ 28 [13],[14],[21],[32]   $ (7) [17],[18],[22],[23]
Investment, Identifier [Axis]: Gainsight, Inc., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[15] 6.75%   6.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 19,254    
Ending balance $ 20,290 [13],[14],[15]   $ 20,290 [13],[14],[15]   $ 19,254 [17],[18],[19]
Investment, Identifier [Axis]: Gainsight, Inc., First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.25% [13],[14],[21],[35]   6.25% [13],[14],[21],[35]   6.00% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ (50)    
Ending balance $ (67) [13],[14],[21],[35]   $ (67) [13],[14],[21],[35]   $ (50) [17],[18],[22],[23]
Investment, Identifier [Axis]: Galls, LLC, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.75% [13],[14],[15]   6.75% [13],[14],[15]   6.75% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 98,458    
Ending balance $ 109,320 [13],[14],[15]   $ 109,320 [13],[14],[15]   $ 98,458 [17],[18],[19]
Investment, Identifier [Axis]: Galls, LLC, First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.75% [13],[14],[15],[21]   6.75% [13],[14],[15],[21]   6.75% [17],[18],[19],[22]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19],[22]     $ 9,999    
Ending balance $ 17,265 [13],[14],[15],[21]   $ 17,265 [13],[14],[15],[21]   $ 9,999 [17],[18],[19],[22]
Investment, Identifier [Axis]: Gaylord Chemical Company, L.L.C., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.50% [13],[14],[15]   6.50% [13],[14],[15]   6.50% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 151,882    
Ending balance $ 151,113 [13],[14],[15]   $ 151,113 [13],[14],[15]   $ 151,882 [17],[18],[19]
Investment, Identifier [Axis]: Gaylord Chemical Company, L.L.C., First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.50% [13],[14],[21],[35]   6.50% [13],[14],[21],[35]   6.50% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ (66)    
Ending balance $ (33) [13],[14],[21],[35]   $ (33) [13],[14],[21],[35]   $ (66) [17],[18],[22],[23]
Investment, Identifier [Axis]: Genesis Acquisition Co. (dba Procare Software), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 3.75% [13],[14],[38]   3.75% [13],[14],[38]   4.00% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 17,630    
Ending balance $ 17,494 [13],[14],[38]   $ 17,494 [13],[14],[38]   $ 17,630 [17],[18],[19]
Investment, Identifier [Axis]: Genesis Acquisition Co. (dba Procare Software), First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 3.75% [13],[14],[38]   3.75% [13],[14],[38]   4.00% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 2,564    
Ending balance $ 2,564 [13],[14],[38]   $ 2,564 [13],[14],[38]   $ 2,564 [17],[18],[19]
Investment, Identifier [Axis]: Gerson Lehrman Group, Inc., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [38] 5.25% [13],[14]   5.25% [13],[14]   5.25% [17],[18]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[38]     $ 151,895    
Ending balance [38] $ 121,939 [13],[14]   $ 121,939 [13],[14]   $ 151,895 [17],[18]
Investment, Identifier [Axis]: Gerson Lehrman Group, Inc., First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.25% [13],[14],[21],[35]   5.25% [13],[14],[21],[35]   5.25% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ 0    
Ending balance $ 0 [13],[14],[21],[35]   $ 0 [13],[14],[21],[35]   $ 0 [17],[18],[22],[23]
Investment, Identifier [Axis]: Global Music Rights, LLC, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.50% [13],[14],[15]   5.50% [13],[14],[15]   5.75% [17],[18]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 7,350    
Ending balance $ 7,407 [13],[14],[15]   $ 7,407 [13],[14],[15]   $ 7,350 [17],[18],[19]
Investment, Identifier [Axis]: Global Music Rights, LLC, First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.50% [13],[14],[21],[35]   5.50% [13],[14],[21],[35]   5.75% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ (13)    
Ending balance $ (3) [13],[14],[21],[35]   $ (3) [13],[14],[21],[35]   $ (13) [17],[18],[22],[23]
Investment, Identifier [Axis]: Gloves Buyer, Inc. (dba Protective Industrial Products), Second lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 8.25% [13],[14],[30]   8.25% [13],[14],[30]   8.25% [17],[18],[27]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[27]     $ 28,884    
Ending balance $ 28,811 [13],[14],[30]   28,811 [13],[14],[30]   $ 28,884 [17],[18],[27]
Investment, Identifier [Axis]: Gloves Holdings, LP (dba Protective Industrial Products), LP Interest          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [14],[25],[26] $ 3,478   3,478    
Investment, Identifier [Axis]: Gloves Holdings, LP (dba Protective Industrial Products), LP Interest          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [18],[28],[29]     $ 3,640    
Ending balance [18],[28],[29]         $ 3,640
Investment, Identifier [Axis]: GovBrands Intermediate, Inc., First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.50% [13],[14],[15],[21],[36]   5.50% [13],[14],[15],[21],[36]   5.50% [17],[18],[22],[27],[31]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[27],[31]     $ 2,330    
Ending balance $ 2,263 [13],[14],[15],[21],[36]   $ 2,263 [13],[14],[15],[21],[36]   $ 2,330 [17],[18],[22],[27],[31]
Investment, Identifier [Axis]: GovBrands Intermediate, Inc., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.50% [13],[14],[15]   5.50% [13],[14],[15]   5.50% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 10,392    
Ending balance $ 10,181 [13],[14],[15]   $ 10,181 [13],[14],[15]   $ 10,392 [17],[18],[19]
Investment, Identifier [Axis]: GovBrands Intermediate, Inc., First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.50% [13],[14],[15],[21]   5.50% [13],[14],[15],[21]   5.50% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ (20)    
Ending balance $ 191 [13],[14],[15],[21]   $ 191 [13],[14],[15],[21]   $ (20) [17],[18],[22],[23]
Investment, Identifier [Axis]: Granicus, Inc. First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[21],[35] 6.50%   6.50%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[21],[35] $ (30)   $ (30)    
Investment, Identifier [Axis]: Granicus, Inc., First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.50% [13],[14],[15],[21],[36]   6.50% [13],[14],[15],[21],[36]   6.50% [17],[18],[19],[22],[31]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19],[31]     $ 1,501    
Ending balance $ 1,470 [13],[14],[15],[21],[36]   $ 1,470 [13],[14],[15],[21],[36]   $ 1,501 [17],[18],[19],[31]
Investment, Identifier [Axis]: Granicus, Inc., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.50% [13],[14],[38]   6.50% [13],[14],[38]   6.50% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 13,259    
Ending balance $ 13,059 [13],[14],[38]   13,059 [13],[14],[38]   $ 13,259 [17],[18],[19]
Investment, Identifier [Axis]: Granicus, Inc., First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[22],[31]         6.50%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     (21)    
Ending balance [17],[18],[22],[23]         $ (21)
Investment, Identifier [Axis]: GrowthCurve Capital Sunrise Co-Invest LP (dba Brightway), LP Interest          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [14],[25],[26] $ 632   632    
Investment, Identifier [Axis]: GrowthCurve Capital Sunrise Co-Invest LP, LP Interest          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [18],[28],[29]     $ 632    
Ending balance [18],[28],[29]         $ 632
Investment, Identifier [Axis]: Guidehouse Inc., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.50% [13],[14],[30]   5.50% [13],[14],[30]   5.50% [17],[18],[27]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[27]     $ 4,603    
Ending balance $ 4,568 [13],[14],[30]   4,568 [13],[14],[30]   $ 4,603 [17],[18],[27]
Investment, Identifier [Axis]: Guidehouse Inc., First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[22]         5.50%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22]     $ (4)    
Ending balance [17],[18],[22]         $ (4)
Investment, Identifier [Axis]: H&F Opportunities LUX III S.À R.L (dba Checkmarx), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 7.50% [13],[14],[16],[30]   7.50% [13],[14],[16],[30]   7.50% [17],[18],[19],[20],[38]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[20],[38]     $ 51,567    
Ending balance $ 51,567 [13],[14],[16],[30]   $ 51,567 [13],[14],[16],[30]   $ 51,567 [17],[18],[20],[38]
Investment, Identifier [Axis]: H&F Opportunities LUX III S.À R.L (dba Checkmarx), First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 7.50% [13],[14],[16],[21],[35]   7.50% [13],[14],[16],[21],[35]   7.50% [17],[18],[20],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[20],[22],[23]     $ 0    
Ending balance $ 0 [13],[14],[16],[21],[35]   0 [13],[14],[16],[21],[35]   $ 0 [17],[18],[20],[22],[23]
Investment, Identifier [Axis]: H-Food Holdings, LLC, LLC Interest          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [18],[28],[29]     13,633    
Ending balance $ 11,318 [14],[25],[26]   $ 11,318 [14],[25],[26]   $ 13,633 [18],[28],[29]
Investment, Identifier [Axis]: H-Food Holdings, LLC, Second lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 7.00% [13],[14],[30]   7.00% [13],[14],[30]   7.00% [17],[18],[27]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[27]     $ 121,800    
Ending balance $ 96,222 [13],[14],[30]   $ 96,222 [13],[14],[30]   $ 121,800 [17],[18],[27]
Investment, Identifier [Axis]: HGH Purchaser, Inc. (dba Horizon Services), First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.00% [13],[14],[15],[21]   6.00% [13],[14],[15],[21]   5.75% [17],[18],[22],[31],[46]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[31],[46]     $ 33,429    
Ending balance $ 29,256 [13],[14],[15],[21]   $ 29,256 [13],[14],[15],[21]   $ 33,429 [17],[18],[22],[31],[46]
Investment, Identifier [Axis]: HGH Purchaser, Inc. (dba Horizon Services), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.00% [13],[14],[15]   6.00% [13],[14],[15]   5.75% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 107,418    
Ending balance $ 145,285 [13],[14],[15]   $ 145,285 [13],[14],[15]   $ 107,418 [17],[18],[19]
Investment, Identifier [Axis]: HGH Purchaser, Inc. (dba Horizon Services), First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.00% [13],[14],[15],[21]   6.00% [13],[14],[15],[21]   5.75% [17],[18],[19],[22]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19],[22]     $ 2,616    
Ending balance $ 9,780 [13],[14],[15],[21]   $ 9,780 [13],[14],[15],[21]   $ 2,616 [17],[18],[19],[22]
Investment, Identifier [Axis]: Hercules Borrower, LLC (dba The Vincit Group), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[38] 6.50%   6.50%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[38] $ 176,897   $ 176,897    
Investment, Identifier [Axis]: Hercules Borrower, LLC (dba The Vincit Group), First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[21],[38] 6.50%   6.50%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[21],[38] $ 2,179   $ 2,179    
Investment, Identifier [Axis]: Hercules Buyer, LLC (dba The Vincit Group), Common Units          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [18],[28],[29],[53]     2,192    
Ending balance $ 2,192 [14],[25],[26],[54]   2,192 [14],[25],[26],[54]   $ 2,192 [18],[28],[29],[53]
Investment, Identifier [Axis]: Hercules Buyer, LLC (dba The Vincit Group), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[19]         6.50%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     178,693    
Ending balance [17],[18],[19]         $ 178,693
Investment, Identifier [Axis]: Hercules Buyer, LLC (dba The Vincit Group), First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[22],[23]         6.50%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ 0    
Ending balance [17],[18],[22],[23]         $ 0
Investment, Identifier [Axis]: Hercules Buyer, LLC (dba The Vincit Group), Unsecured notes          
Schedule of Investments [Line Items]          
Basis spread, variable rate [14],[23],[54] 0.48%   0.48%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [18],[40],[53]     $ 5,135    
Ending balance $ 5,135 [14],[39],[54]   $ 5,135 [14],[39],[54]   5,135 [18],[40],[53]
Investment, Identifier [Axis]: Hg Genesis 8 Sumoco Limited, Unsecured facility          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[16],[39] 7.50%   7.50%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[20],[42]     $ 47,207    
Ending balance $ 40,371 [13],[14],[16],[39]   $ 40,371 [13],[14],[16],[39]   47,207 [17],[18],[20],[42]
Investment, Identifier [Axis]: Hg Genesis 9 SumoCo Limited, Unsecured facility          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[16],[55] 7.00%   7.00%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[16],[55] $ 42,227   $ 42,227    
Investment, Identifier [Axis]: Hg Saturn Luchaco Limited, Unsecured facility          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[16],[39] 7.50%   7.50%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[20],[42]     $ 132,523    
Ending balance $ 118,346 [13],[14],[16],[39]   118,346 [13],[14],[16],[39]   $ 132,523 [17],[18],[20],[42]
Investment, Identifier [Axis]: Hissho Sushi Holdings, LLC, Class A units          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [14],[25],[26] $ 75   $ 75    
Investment, Identifier [Axis]: Hissho Sushi Merger Sub LLC, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[32] 6.00%   6.00%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[32] $ 901   $ 901    
Investment, Identifier [Axis]: Hissho Sushi Merger Sub LLC, First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[21],[32] 6.00%   6.00%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[21],[32] $ 4   $ 4    
Investment, Identifier [Axis]: Hometown Food Company, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.00% [13],[14],[30]   5.00% [13],[14],[30]   5.00% [17],[18],[27]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[27]     $ 15,787    
Ending balance $ 14,487 [13],[14],[30]   $ 14,487 [13],[14],[30]   $ 15,787 [17],[18],[27]
Investment, Identifier [Axis]: Hometown Food Company, First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.00% [13],[14],[21],[30]   5.00% [13],[14],[21],[30]   5.00% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ (42)    
Ending balance $ 685 [13],[14],[21],[30]   $ 685 [13],[14],[21],[30]   $ (42) [17],[18],[22],[23]
Investment, Identifier [Axis]: Hyland Software, Inc., Second lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.25% [13],[14],[30]   6.25% [13],[14],[30]   6.25% [17],[18],[27]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[27]     $ 15,579    
Ending balance $ 15,172 [13],[14],[30]   $ 15,172 [13],[14],[30]   $ 15,579 [17],[18],[27]
Investment, Identifier [Axis]: IG Investments Holdings, LLC (dba Insight Global), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.00% [13],[14],[15]   6.00% [13],[14],[15]   6.00% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 50,008    
Ending balance $ 49,632 [13],[14],[15]   $ 49,632 [13],[14],[15]   $ 50,008 [17],[18],[19]
Investment, Identifier [Axis]: IG Investments Holdings, LLC (dba Insight Global), First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.00% [13],[14],[21],[35]   6.00% [13],[14],[21],[35]   6.00% [17],[18],[19],[22]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19],[22]     $ 1,917    
Ending balance $ (70) [13],[14],[21],[35]   (70) [13],[14],[21],[35]   $ 1,917 [17],[18],[19],[22]
Investment, Identifier [Axis]: IQN Holding Corp. (dba Beeline), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[38]         5.50%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[38]     150,639    
Ending balance [17],[18],[38]         $ 150,639
Investment, Identifier [Axis]: IQN Holding Corp. (dba Beeline), First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[22],[23]         5.50%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ 0    
Ending balance [17],[18],[22],[23]         $ 0
Investment, Identifier [Axis]: Ideal Image Development, LLC, First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[21],[35],[36] 6.50%   6.50%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[21],[35],[36] $ (7)   $ (7)    
Investment, Identifier [Axis]: Ideal Image Development, LLC, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[37] 6.50%   6.50%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[37] $ 11,473   $ 11,473    
Investment, Identifier [Axis]: Ideal Image Development, LLC, First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[21],[35] 6.50%   6.50%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[21],[35] $ (37)   $ (37)    
Investment, Identifier [Axis]: Ideal Tridon Holdings, Inc., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.25% [13],[14],[15]   5.25% [13],[14],[15]   5.25% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 53,209    
Ending balance $ 52,699 [13],[14],[15]   $ 52,699 [13],[14],[15]   $ 53,209 [17],[18],[19]
Investment, Identifier [Axis]: Ideal Tridon Holdings, Inc., First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.25% [13],[14],[21]   5.25% [13],[14],[21]   5.25% [17],[18],[22],[27]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[27]     $ 1,800    
Ending balance $ 0 [13],[14],[21]   0 [13],[14],[21]   $ 1,800 [17],[18],[22],[27]
Investment, Identifier [Axis]: Imperial Parking Canada, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[56]         6.00%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[56]     $ 26,707    
Ending balance [17],[18],[56]         $ 26,707
Investment, Identifier [Axis]: Imprivata, Inc., Second lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[37] 6.25%   6.25%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[37] $ 867   $ 867    
Investment, Identifier [Axis]: Indigo Buyer, Inc. (dba Inovar Packaging Group), First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[21],[36] 5.75%   5.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[21],[36] $ 0   $ 0    
Investment, Identifier [Axis]: Indigo Buyer, Inc. (dba Inovar Packaging Group), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[32] 5.75%   5.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[32] $ 647   $ 647    
Investment, Identifier [Axis]: Indigo Buyer, Inc. (dba Inovar Packaging Group), First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[21],[32] 5.75%   5.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[21],[32] $ 16   $ 16    
Investment, Identifier [Axis]: Individual Foodservice Holdings, LLC, First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[22],[31],[38]         6.25%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[31],[38]     27,909    
Ending balance [17],[18],[22],[31],[38]         $ 27,909
Investment, Identifier [Axis]: Individual Foodservice Holdings, LLC, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[19]         6.25%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 140,156    
Ending balance [17],[18],[19]         $ 140,156
Investment, Identifier [Axis]: Individual Foodservice Holdings, LLC, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[15] 6.25%   6.25%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[15] $ 133,110   $ 133,110    
Investment, Identifier [Axis]: Individual Foodservice Holdings, LLC, First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.25% [13],[14],[21],[35]   6.25% [13],[14],[21],[35]   6.25% [17],[18],[22],[27]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[27]     $ 851    
Ending balance $ (108) [13],[14],[21],[35]   $ (108) [13],[14],[21],[35]   $ 851 [17],[18],[22],[27]
Investment, Identifier [Axis]: Innovation Ventures HoldCo, LLC (dba 5 Hour Energy), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[37] 6.25%   6.25%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[37] $ 121,564   $ 121,564    
Investment, Identifier [Axis]: Inovalon Holdings, Inc, Second lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[15] 10.50%   10.50%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[15] $ 90,502   $ 90,502    
Investment, Identifier [Axis]: Inovalon Holdings, Inc., First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 3.50% [13],[14],[21],[35],[36]   3.50% [13],[14],[21],[35],[36]   5.75% [17],[18],[22],[23],[31]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23],[31]     $ (237)    
Ending balance $ (332) [13],[14],[21],[35],[36]   $ (332) [13],[14],[21],[35],[36]   $ (237) [17],[18],[22],[23],[31]
Investment, Identifier [Axis]: Inovalon Holdings, Inc., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.25% [13],[14],[15]   6.25% [13],[14],[15]   5.75% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 173,283    
Ending balance $ 176,018 [13],[14],[15]   176,018 [13],[14],[15]   $ 173,283 [17],[18],[19]
Investment, Identifier [Axis]: Inovalon Holdings, Inc., Second lien senior secured loan          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     82,967    
Ending balance [17],[18],[19]         $ 82,967
Investment, Identifier [Axis]: Insight CP (Blocker) Holdings, L.P. (dba CivicPlus, LLC), LP Interest          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [14],[16],[25],[26] $ 1,230   $ 1,230    
Investment, Identifier [Axis]: Integrity Marketing Acquisition, LLC, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [38] 5.75% [13],[14]   5.75% [13],[14]   5.75% [17],[18]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[38]     $ 218,876    
Ending balance [38] $ 216,658 [13],[14]   $ 216,658 [13],[14]   $ 218,876 [17],[18]
Investment, Identifier [Axis]: Integrity Marketing Acquisition, LLC, First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.75% [13],[14],[21],[35]   5.75% [13],[14],[21],[35]   5.75% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ 0    
Ending balance $ (37) [13],[14],[21],[35]   $ (37) [13],[14],[21],[35]   $ 0 [17],[18],[22],[23]
Investment, Identifier [Axis]: Intelerad Medical Systems Incorporated (fka 11849573 Canada Inc.), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.50% [13],[14],[16],[32]   6.50% [13],[14],[16],[32]   6.25% [17],[18],[19],[20]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19],[20]     $ 115,395    
Ending balance $ 117,499 [13],[14],[16],[32]   $ 117,499 [13],[14],[16],[32]   $ 115,395 [17],[18],[19],[20]
Investment, Identifier [Axis]: Intelerad Medical Systems Incorporated (fka 11849573 Canada Inc.), First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.50% [13],[14],[16],[21],[32]   6.50% [13],[14],[16],[21],[32]   6.25% [17],[18],[19],[20],[22]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19],[20],[22]     $ 2,972    
Ending balance $ 2,960 [13],[14],[16],[21],[32]   $ 2,960 [13],[14],[16],[21],[32]   $ 2,972 [17],[18],[19],[20],[22]
Investment, Identifier [Axis]: Interoperability Bidco, Inc. (dba Lyniate), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[32] 7.00%   7.00%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[32] $ 65,956   $ 65,956    
Investment, Identifier [Axis]: Interoperability Bidco, Inc. (dba Lyniate), First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[21],[35] 7.00%   7.00%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[21],[35] $ (30)   $ (30)    
Investment, Identifier [Axis]: Interoperability Bidco, Inc., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[38]         5.75%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[38]     75,270    
Ending balance [17],[18],[38]         $ 75,270
Investment, Identifier [Axis]: Interoperability Bidco, Inc., First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[22],[23]         5.75%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     0    
Ending balance [17],[18],[22],[23]         $ 0
Investment, Identifier [Axis]: KOBHG Holdings, L.P. (dba OB Hospitalist), Class A Interests          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [18],[28],[29]     6,670    
Ending balance 6,445 [14],[25],[26]   6,445 [14],[25],[26]   6,670 [18],[28],[29]
Investment, Identifier [Axis]: KPCI Holdings, LP, Class A Units          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [18],[28],[29]     37,331    
Ending balance $ 32,111 [14],[25],[26]   32,111 [14],[25],[26]   $ 37,331 [18],[28],[29]
Investment, Identifier [Axis]: KPSKY Acquisition, Inc. (dba BluSky), First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[22],[31],[34]         4.50%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[31],[34]     $ 248    
Ending balance [17],[18],[22],[31],[34]         $ 248
Investment, Identifier [Axis]: KPSKY Acquisition, Inc. (dba BluSky), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.50% [13],[14],[30]   5.50% [13],[14],[30]   5.50% [17],[18],[27]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[27]     $ 4,386    
Ending balance $ 4,816 [13],[14],[30]   4,816 [13],[14],[30]   $ 4,386 [17],[18],[27]
Investment, Identifier [Axis]: KS Management Services, L.L.C., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[38]         4.25%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[38]     $ 122,500    
Ending balance [17],[18],[38]         $ 122,500
Investment, Identifier [Axis]: KUSRP Intermediate, Inc. (dba U.S. Retirement and Benefits Partners), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[38] 9.50%   9.50%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 30,612    
Ending balance $ 33,299 [13],[14],[38]   $ 33,299 [13],[14],[38]   $ 30,612 [17],[18],[19]
Investment, Identifier [Axis]: Kaseya Inc., First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[21],[35],[36] 5.75%   5.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[21],[35],[36] $ (3)   $ (3)    
Investment, Identifier [Axis]: Kaseya Inc., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14] 5.75%   5.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14] $ 18,497   $ 18,497    
Investment, Identifier [Axis]: Kaseya Inc., First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[21],[35] 5.75%   5.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[21],[35] $ (14)   $ (14)    
Investment, Identifier [Axis]: Knockout Intermediate Holdings I Inc. (dba Kaseya),Perpetual Preferred Stock          
Schedule of Investments [Line Items]          
Basis spread, variable rate [14],[23],[26] 11.75%   11.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [14],[23],[26] $ 13,790   $ 13,790    
Investment, Identifier [Axis]: LTP Holdco, LLC, , Unsecured facility          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[37] 10.75%   10.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[37] $ 3,867   $ 3,867    
Investment, Identifier [Axis]: Lazer Spot G B Holdings, Inc., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.75% [13],[14],[38]   5.75% [13],[14],[38]   5.75% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 144,064    
Ending balance $ 142,964 [13],[14],[38]   $ 142,964 [13],[14],[38]   $ 144,064 [17],[18],[19]
Investment, Identifier [Axis]: Lazer Spot G B Holdings, Inc., First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.75% [13],[14],[21],[35]   5.75% [13],[14],[21],[35]   5.75% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ 0    
Ending balance $ 0 [13],[14],[21],[35]   $ 0 [13],[14],[21],[35]   $ 0 [17],[18],[22],[23]
Investment, Identifier [Axis]: Learning Care Group (US) No. 2 Inc., Second lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 7.50% [13],[14],[15]   7.50% [13],[14],[15]   7.50% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 26,293    
Ending balance $ 26,360 [13],[14],[15]   $ 26,360 [13],[14],[15]   $ 26,293 [17],[18],[19]
Investment, Identifier [Axis]: Lignetics Investment Corp. First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[15],[21] 6.00%   6.00%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[15],[21] $ 4,016   $ 4,016    
Investment, Identifier [Axis]: Lignetics Investment Corp., First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.00% [13],[14],[21],[35],[36]   6.00% [13],[14],[21],[35],[36]   6.00% [17],[18],[22],[23],[31]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23],[31]     $ (49)    
Ending balance $ (118) [13],[14],[21],[35],[36]   $ (118) [13],[14],[21],[35],[36]   $ (49) [17],[18],[22],[23],[31]
Investment, Identifier [Axis]: Lignetics Investment Corp., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.00% [13],[14],[15]   6.00% [13],[14],[15]   6.00% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 30,980    
Ending balance $ 30,203 [13],[14],[15]   30,203 [13],[14],[15]   $ 30,980 [17],[18],[19]
Investment, Identifier [Axis]: Lignetics Investment Corp., First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[19],[22]         6.00%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19],[22]     $ 725    
Ending balance [17],[18],[19],[22]         $ 725
Investment, Identifier [Axis]: LineStar Integrity Services LLC, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [38] 7.25% [13],[14]   7.25% [13],[14]   7.25% [17],[18]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[38]     $ 72,788    
Ending balance [38] $ 73,933 [13],[14]   73,933 [13],[14]   $ 72,788 [17],[18]
Investment, Identifier [Axis]: Litera Bidco LLC, First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[22],[27],[31]         6.00%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[27],[31]     $ 1,998    
Ending balance [17],[18],[22],[27],[31]         $ 1,998
Investment, Identifier [Axis]: Litera Bidco LLC, First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.89% [13],[14],[30]   5.89% [13],[14],[30]   5.87% [17],[18],[27]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[27]     $ 154,049    
Ending balance $ 148,733 [13],[14],[30]   $ 148,733 [13],[14],[30]   $ 154,049 [17],[18],[27]
Investment, Identifier [Axis]: Litera Bidco LLC, First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 5.75% [13],[14],[21],[35]   5.75% [13],[14],[21],[35]   5.75% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ 0    
Ending balance $ (29) [13],[14],[21],[35]   $ (29) [13],[14],[21],[35]   $ 0 [17],[18],[22],[23]
Investment, Identifier [Axis]: Lytx, Inc., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.75% [13],[14],[37]   6.75% [13],[14],[37]   6.75% [17],[18],[27]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[27]     $ 71,195    
Ending balance $ 70,119 [13],[14],[37]   70,119 [13],[14],[37]   $ 71,195 [17],[18],[27]
Investment, Identifier [Axis]: MHE Intermediate Holdings, LLC (dba OnPoint Group), First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[19],[22],[31]         5.75%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19],[22],[31]     $ 13,286    
Ending balance [17],[18],[19],[22],[31]         $ 13,286
Investment, Identifier [Axis]: MHE Intermediate Holdings, LLC (dba OnPoint Group), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.00% [13],[14],[45]   6.00% [13],[14],[45]   5.75% [17],[18],[19]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[19]     $ 158,718    
Ending balance $ 179,957 [13],[14],[45]   $ 179,957 [13],[14],[45]   $ 158,718 [17],[18],[19]
Investment, Identifier [Axis]: MHE Intermediate Holdings, LLC (dba OnPoint Group), First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 6.00% [13],[14],[21],[35]   6.00% [13],[14],[21],[35]   5.75% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [18],[22],[23]     $ (155)    
Ending balance $ (194) [13],[14],[21],[35]   $ (194) [13],[14],[21],[35]   $ (155) [18],[22],[23]
Investment, Identifier [Axis]: MINDBODY, Inc., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 8.50% [13],[14],[15]   8.50% [13],[14],[15]   8.50% [17],[18],[19],[38]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[38]     $ 67,127    
Ending balance $ 67,902 [13],[14],[15]   $ 67,902 [13],[14],[15]   $ 67,127 [17],[18],[38]
Investment, Identifier [Axis]: MINDBODY, Inc., First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate 8.00% [13],[14],[21],[35]   8.00% [13],[14],[21],[35]   7.00% [17],[18],[22],[23]
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ 0    
Ending balance $ 0 [13],[14],[21],[35]   0 [13],[14],[21],[35]   $ 0 [17],[18],[22],[23]
Investment, Identifier [Axis]: Maia Aggregator, LP, Class A-2 Units          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [14],[25],[26] $ 169   $ 169    
Investment, Identifier [Axis]: Mario Midco Holdings Inc.(dba Len the Plumber), First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[21],[35] 5.75%   5.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[21],[35] $ (17)   $ (17)    
Investment, Identifier [Axis]: Mario Purchaser, LLC (dba Len the Plumber), First lien senior secured delayed draw term loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[21],[36],[37] 5.75%   5.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[21],[36],[37] $ 1,988   $ 1,988    
Investment, Identifier [Axis]: Mario Purchaser, LLC (dba Len the Plumber), First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[37] 5.75%   5.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[37] $ 12,911   $ 12,911    
Investment, Identifier [Axis]: Medline Borrower, LP, First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[21],[35] 3.25%   3.25%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[21],[35] $ (719)   $ (719)    
Investment, Identifier [Axis]: Medline Intermediate, LP, First lien senior secured revolving loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[22],[23]         3.25%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance [17],[18],[22],[23]     $ (162)    
Ending balance [17],[18],[22],[23]         $ (162)
Investment, Identifier [Axis]: MessageBird BidCo B.V., First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [13],[14],[16],[38] 6.75%   6.75%    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance [13],[14],[16],[38] $ 75,268   $ 75,268    
Investment, Identifier [Axis]: MessageBird BidCo B.V.,First lien senior secured loan          
Schedule of Investments [Line Items]          
Basis spread, variable rate [17],[18],[19],[20]         6.75%
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     75,460    
Ending balance         $ 75,460