Quarterly report pursuant to Section 13 or 15(d)

Consolidated Schedule of Investments In and Advances to Affiliates (Details)

v3.22.2.2
Consolidated Schedule of Investments In and Advances to Affiliates (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2022
Sep. 30, 2021
Sep. 30, 2022
Sep. 30, 2021
Dec. 31, 2021
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss) $ 5,031 $ 8,305 $ 3,302 $ 10,575  
Amount of Unrealized Gain/(Loss) (10,081) 38,631 (19,922) 117,072  
Control investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     (5,822) (4,459)  
Amount of Unrealized Gain/(Loss)     20,618 65,756  
Amount of Interest, Fees or Dividends Credited to Income     110,751 85,904  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     1,489,257 1,113,725  
Gross Additions     280,134 340,046  
Gross Reductions     128,214 117,553  
Ending balance 1,599,429 1,336,218 1,599,429 1,336,218  
Control investments | Midwest          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance $ 346,535 $ 297,953 $ 346,535 $ 297,953  
Net assets, percentage 21.70% 25.90% 21.70% 25.90%  
Control investments | Northeast          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance   $ 117,017   $ 117,017  
Net assets, percentage   10.80%   10.80%  
Control investments | Southeast          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance $ 16,360 $ 44,538 $ 16,360 $ 44,538  
Net assets, percentage 1.00% 1.20% 1.00% 1.20%  
Control investments | Southwest          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance $ 593,513 $ 573,437 $ 593,513 $ 573,437  
Net assets, percentage 37.10% 44.40% 37.10% 44.40%  
Control investments | West          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance $ 498,340 $ 303,273 $ 498,340 $ 303,273  
Net assets, percentage 31.20% 37.30% 31.20% 37.30%  
Control investments | Northeast Region and Canada          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance $ 144,681   $ 144,681    
Net assets, percentage 9.00%   9.00%    
Affiliate investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     $ 1,340 $ 3,962  
Amount of Unrealized Gain/(Loss)     3,703 30,518  
Amount of Interest, Fees or Dividends Credited to Income     38,300 34,785  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     549,214 366,301  
Gross Additions     92,606 195,509  
Gross Reductions     56,642 88,934  
Ending balance $ 552,581 $ 485,139 552,581 485,139  
Affiliate investments | Midwest          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance $ 67,491 $ 41,535 $ 67,491 $ 41,535  
Net assets, percentage 12.20% 13.90% 12.20% 13.90%  
Affiliate investments | Northeast          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance   $ 144,241   $ 144,241  
Net assets, percentage   21.70%   21.70%  
Affiliate investments | Southeast          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance $ 196,507 $ 134,602 $ 196,507 $ 134,602  
Net assets, percentage 35.60% 40.50% 35.60% 40.50%  
Affiliate investments | Southwest          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance $ 99,261 $ 109,522 $ 99,261 $ 109,522  
Net assets, percentage 18.00% 20.50% 18.00% 20.50%  
Affiliate investments | West          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance $ 83,950 $ 55,239 $ 83,950 $ 55,239  
Net assets, percentage 15.20% 17.30% 15.20% 17.30%  
Affiliate investments | Northeast Region and Canada          
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Ending balance $ 105,372   $ 105,372    
Net assets, percentage 19.10%   19.10%    
Investment, Identifier [Axis]: Dalton US Inc., Secured Debt One August 16, 2022          
Schedule of Investments [Line Items]          
Total Rate [1],[2],[3] 11.13%   11.13%    
Spread [1],[2],[3] 8.00%   8.00%    
Investment, Identifier [Axis]: Dalton US Inc., Secured Debt Three August 16, 2022          
Schedule of Investments [Line Items]          
Total Rate [1],[2],[3] 11.31%   11.31%    
Spread [1],[2],[3] 8.00%   8.00%    
Investment, Identifier [Axis]: Dalton US Inc., Secured Debt Two August 16, 2022          
Schedule of Investments [Line Items]          
Spread [1],[2],[3],[4] 8.00%   8.00%    
Investment, Identifier [Axis]: Salient Partners L.P., Secured Debt September 30,2021          
Schedule of Investments [Line Items]          
Total Rate [5],[6]         6.00%
Spread [5],[6]         5.00%
Investment, Identifier [Axis]: Winter Services LLC, Secured Debt November 19,2021          
Schedule of Investments [Line Items]          
Total Rate [6],[7]         8.00%
Spread [6],[7]         7.00%
Investment, Identifier [Axis]: 2717 MH, L.P., LP Interests (2717 HPP-MS, L.P.) | Other controlled investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     $ 0 $ 0  
Amount of Unrealized Gain/(Loss)     0 0  
Amount of Interest, Fees or Dividends Credited to Income     0 0  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     0 250  
Gross Additions     244 0  
Gross Reductions     0 250  
Ending balance $ 244 $ 0 244 0  
Investment, Identifier [Axis]: 2717 MH, L.P., LP Interests (2717 MH, L.P.) | Other controlled investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     0 0  
Amount of Unrealized Gain/(Loss)     1,979 585  
Amount of Interest, Fees or Dividends Credited to Income     0 0  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     3,971 2,702  
Gross Additions     3,171 689  
Gross Reductions     0 0  
Ending balance 7,142 $ 3,391 7,142 $ 3,391  
Investment, Identifier [Axis]: AAC Holdings, Inc, Secured Debt | Affiliate investments          
Schedule of Investments [Line Items]          
Total Rate   18.00%   18.00%  
PIK Rate   8.00%   8.00%  
Amount of Realized Gain/(Loss)       $ 0  
Amount of Unrealized Gain/(Loss)       (89)  
Amount of Interest, Fees or Dividends Credited to Income       1,329  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       9,187  
Gross Additions       744  
Gross Reductions       223  
Ending balance   $ 9,708   9,708  
Investment, Identifier [Axis]: AAC Holdings, Inc, Warrants | Affiliate investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)       0  
Amount of Unrealized Gain/(Loss)       (968)  
Amount of Interest, Fees or Dividends Credited to Income       0  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       2,938  
Gross Additions       0  
Gross Reductions       968  
Ending balance   1,970   1,970  
Investment, Identifier [Axis]: AAC Holdings, Inc., Common Stock | Affiliate investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     0 0  
Amount of Unrealized Gain/(Loss)     (2,004) (1,038)  
Amount of Interest, Fees or Dividends Credited to Income     0 0  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     2,079 3,148  
Gross Additions     0 0  
Gross Reductions     2,004 1,038  
Ending balance $ 75 2,110 $ 75 2,110  
Investment, Identifier [Axis]: AAC Holdings, Inc., Secured Debt | Affiliate investments          
Schedule of Investments [Line Items]          
Total Rate 18.00%   18.00%    
PIK Rate 18.00%   18.00%    
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     143    
Amount of Interest, Fees or Dividends Credited to Income     1,492    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     9,794    
Gross Additions     1,182    
Gross Reductions     0    
Ending balance $ 10,976   $ 10,976    
Investment, Identifier [Axis]: AAC Holdings, Inc., Secured Debt December 11, 2020          
Schedule of Investments [Line Items]          
Total Rate [8] 18.00%   18.00%    
PIK Rate [8] 18.00%   18.00%    
Investment, Identifier [Axis]: AAC Holdings, Inc., Secured Debt December 11,2020          
Schedule of Investments [Line Items]          
Total Rate [5]         18.00%
PIK Rate [5]         8.00%
Investment, Identifier [Axis]: AAC Holdings, Inc., Warrant | Affiliate investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     (1,865)    
Amount of Interest, Fees or Dividends Credited to Income     0    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     1,940    
Gross Additions     0    
Gross Reductions     1,865    
Ending balance $ 75   $ 75    
Investment, Identifier [Axis]: AB Centers Acquisition Corporation, Secured Debt One September 06, 2022          
Schedule of Investments [Line Items]          
Spread [1],[2],[3],[4] 6.00%   6.00%    
Investment, Identifier [Axis]: AB Centers Acquisition Corporation, Secured Debt Three September 06, 2022          
Schedule of Investments [Line Items]          
Total Rate [1],[2],[3] 9.17%   9.17%    
Spread [1],[2],[3] 6.00%   6.00%    
Investment, Identifier [Axis]: AB Centers Acquisition Corporation, Secured Debt Two September 06, 2022          
Schedule of Investments [Line Items]          
Spread [1],[2],[3],[4] 6.00%   6.00%    
Investment, Identifier [Axis]: ADS Tactical, Inc. Secured Debt March 29, 2021          
Schedule of Investments [Line Items]          
Total Rate [3],[8] 8.80%   8.80%    
Spread [3],[8] 5.75%   5.75%    
Investment, Identifier [Axis]: ADS Tactical, Inc., Secured Debt March 29,2021          
Schedule of Investments [Line Items]          
Total Rate [5],[6]         6.75%
Spread [5],[6]         5.75%
Investment, Identifier [Axis]: AFG Capital Group, LLC, Preferred Member Units | Affiliate investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)       0  
Amount of Unrealized Gain/(Loss)       1,570  
Amount of Interest, Fees or Dividends Credited to Income       200  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       5,810  
Gross Additions       1,570  
Gross Reductions       0  
Ending balance   $ 7,380   $ 7,380  
Investment, Identifier [Axis]: AFG Capital Group, LLC, Preferred Member Units One | Affiliate investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     0    
Amount of Interest, Fees or Dividends Credited to Income     2    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     144    
Gross Additions     0    
Gross Reductions     144    
Ending balance $ 0   0    
Investment, Identifier [Axis]: AFG Capital Group, LLC, Preferred Member Units Two | Affiliate investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     0    
Amount of Unrealized Gain/(Loss)     1,040    
Amount of Interest, Fees or Dividends Credited to Income     200    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     7,740    
Gross Additions     1,040    
Gross Reductions     0    
Ending balance $ 8,780   $ 8,780    
Investment, Identifier [Axis]: AFG Capital Group, LLC, Secured Debt | Affiliate investments          
Schedule of Investments [Line Items]          
Total Rate   10.00%   10.00%  
Amount of Realized Gain/(Loss)       $ 0  
Amount of Unrealized Gain/(Loss)       0  
Amount of Interest, Fees or Dividends Credited to Income       26  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       491  
Gross Additions       0  
Gross Reductions       260  
Ending balance   $ 231   231  
Investment, Identifier [Axis]: AFG Capital Group, LLC, Secured Debt April 25,2019          
Schedule of Investments [Line Items]          
Total Rate         10.00%
Investment, Identifier [Axis]: AMEREQUIP LLC., Secured Debt One August 31, 2022          
Schedule of Investments [Line Items]          
Spread [1],[2],[3],[4] 7.40%   7.40%    
Investment, Identifier [Axis]: AMEREQUIP LLC., Secured Debt Two August 31, 2022          
Schedule of Investments [Line Items]          
Total Rate [1],[2],[3] 9.84%   9.84%    
Spread [1],[2],[3] 7.40%   7.40%    
Investment, Identifier [Axis]: ASC Interests, LLC, Member Units | Other controlled investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     $ 0 0  
Amount of Unrealized Gain/(Loss)     80 (400)  
Amount of Interest, Fees or Dividends Credited to Income     0 0  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     720 1,120  
Gross Additions     80 0  
Gross Reductions     0 400  
Ending balance $ 800 $ 720 $ 800 $ 720  
Investment, Identifier [Axis]: ASC Interests, LLC, Secured Debt | Other controlled investments          
Schedule of Investments [Line Items]          
Total Rate   13.00%   13.00%  
Amount of Realized Gain/(Loss)       $ 0  
Amount of Unrealized Gain/(Loss)       0  
Amount of Interest, Fees or Dividends Credited to Income       193  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       1,715  
Gross Additions       116  
Gross Reductions       0  
Ending balance   $ 1,831   1,831  
Investment, Identifier [Axis]: ASC Interests, LLC, Secured Debt August 1,2013          
Schedule of Investments [Line Items]          
Total Rate         13.00%
Investment, Identifier [Axis]: ASC Interests, LLC, Secured Debt December 31,2019          
Schedule of Investments [Line Items]          
Total Rate         13.00%
Investment, Identifier [Axis]: ASC Interests, LLC, Secured Debt One | Other controlled investments          
Schedule of Investments [Line Items]          
Total Rate 13.00%   13.00%    
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     0    
Amount of Interest, Fees or Dividends Credited to Income     24    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     200    
Gross Additions     130    
Gross Reductions     30    
Ending balance $ 300   $ 300    
Investment, Identifier [Axis]: ASC Interests, LLC, Secured Debt One December 31,2019          
Schedule of Investments [Line Items]          
Total Rate 13.00%   13.00%    
Investment, Identifier [Axis]: ASC Interests, LLC, Secured Debt Two | Other controlled investments          
Schedule of Investments [Line Items]          
Total Rate 13.00%   13.00%    
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     0    
Amount of Interest, Fees or Dividends Credited to Income     211    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     1,636    
Gross Additions     12    
Gross Reductions     0    
Ending balance $ 1,648   $ 1,648    
Investment, Identifier [Axis]: ASC Interests, LLC, Secured Debt Two August 1,2013          
Schedule of Investments [Line Items]          
Total Rate 13.00%   13.00%    
Investment, Identifier [Axis]: ASK (Analytical Systems Keco Holdings, LLC), Preferred Member Units One | Majority-owned investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)       0  
Amount of Unrealized Gain/(Loss)       (3,200)  
Amount of Interest, Fees or Dividends Credited to Income       0  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       3,200  
Gross Additions       0  
Gross Reductions       3,200  
Ending balance   0   0  
Investment, Identifier [Axis]: ASK (Analytical Systems Keco Holdings, LLC), Preferred Member Units Two | Majority-owned investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)       0  
Amount of Unrealized Gain/(Loss)       2,356  
Amount of Interest, Fees or Dividends Credited to Income       0  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       0  
Gross Additions       4,783  
Gross Reductions       0  
Ending balance   $ 4,783   $ 4,783  
Investment, Identifier [Axis]: ASK (Analytical Systems Keco Holdings, LLC), Secured Debt | Majority-owned investments          
Schedule of Investments [Line Items]          
Total Rate   12.00%   12.00%  
Spread   10.00%   10.00%  
Amount of Realized Gain/(Loss)       $ 0  
Amount of Unrealized Gain/(Loss)       0  
Amount of Interest, Fees or Dividends Credited to Income       520  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       4,873  
Gross Additions       134  
Gross Reductions       220  
Ending balance   $ 4,787   4,787  
Investment, Identifier [Axis]: ASK (Analytical Systems Keco Holdings, LLC), Warrants | Majority-owned investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)       0  
Amount of Unrealized Gain/(Loss)       (10)  
Amount of Interest, Fees or Dividends Credited to Income       0  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       10  
Gross Additions       0  
Gross Reductions       10  
Ending balance   $ 0   $ 0  
Investment, Identifier [Axis]: ASK Analytical Systems Keco Holdings, LLC, Preferred Member Units One | Majority-owned investments          
Schedule of Investments [Line Items]          
Total Rate 12.63%   12.63%    
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     0    
Amount of Interest, Fees or Dividends Credited to Income     0    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     0    
Gross Additions     0    
Gross Reductions     0    
Ending balance $ 0   0    
Investment, Identifier [Axis]: ASK Analytical Systems Keco Holdings, LLC, Preferred Member Units Two | Majority-owned investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     0    
Amount of Unrealized Gain/(Loss)     (1,050)    
Amount of Interest, Fees or Dividends Credited to Income     0    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     4,894    
Gross Additions     0    
Gross Reductions     1,050    
Ending balance $ 3,844   $ 3,844    
Investment, Identifier [Axis]: ASK Analytical Systems Keco Holdings, LLC, Secured Debt One | Majority-owned investments          
Schedule of Investments [Line Items]          
Spread 10.00%   10.00%    
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     0    
Amount of Interest, Fees or Dividends Credited to Income     4    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     (4)    
Gross Additions     1    
Gross Reductions     0    
Ending balance $ (3)   $ (3)    
Investment, Identifier [Axis]: ASK Analytical Systems Keco Holdings, LLC, Secured Debt Two | Majority-owned investments          
Schedule of Investments [Line Items]          
Total Rate 12.63%   12.63%    
Spread 10.00%   10.00%    
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     0    
Amount of Interest, Fees or Dividends Credited to Income     506    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     4,740    
Gross Additions     65    
Gross Reductions     210    
Ending balance $ 4,595   4,595    
Investment, Identifier [Axis]: ASK Analytical Systems Keco Holdings, LLC, Warrants | Majority-owned investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     0    
Amount of Unrealized Gain/(Loss)     0    
Amount of Interest, Fees or Dividends Credited to Income     0    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     0    
Gross Additions     0    
Gross Reductions     0    
Ending balance $ 0   $ 0    
Investment, Identifier [Axis]: ATS Operating, LLC, Secured Debt One January 18,2022          
Schedule of Investments [Line Items]          
Spread [1],[2],[3],[4] 6.50%   6.50%    
Investment, Identifier [Axis]: ATS Operating, LLC, Secured Debt Three January 18,2022          
Schedule of Investments [Line Items]          
Total Rate [1],[2],[3] 9.84%   9.84%    
Spread [1],[2],[3] 7.50%   7.50%    
Investment, Identifier [Axis]: ATS Operating, LLC, Secured Debt Two January 18,2022          
Schedule of Investments [Line Items]          
Total Rate [1],[2],[3] 7.84%   7.84%    
Spread [1],[2],[3] 5.50%   5.50%    
Investment, Identifier [Axis]: ATS Workholding, LLC, Preferred Member Units | Other controlled investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     0    
Amount of Interest, Fees or Dividends Credited to Income     0    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     0    
Gross Additions     0    
Gross Reductions     0    
Ending balance $ 0   $ 0    
Investment, Identifier [Axis]: ATS Workholding, LLC, Secured Debt | Other controlled investments          
Schedule of Investments [Line Items]          
Total Rate   5.00%   5.00%  
Amount of Realized Gain/(Loss)       $ 0  
Amount of Unrealized Gain/(Loss)       (304)  
Amount of Interest, Fees or Dividends Credited to Income       0  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       3,347  
Gross Additions       0  
Gross Reductions       472  
Ending balance   $ 2,875   $ 2,875  
Investment, Identifier [Axis]: ATS Workholding, LLC, Secured Debt November 16,2017          
Schedule of Investments [Line Items]          
Total Rate [7],[9]         5.00%
Investment, Identifier [Axis]: ATS Workholding, LLC, Secured Debt One | Other controlled investments          
Schedule of Investments [Line Items]          
Total Rate 5.00%   5.00%    
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     (411)    
Amount of Interest, Fees or Dividends Credited to Income     0    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     1,088    
Gross Additions     147    
Gross Reductions     435    
Ending balance $ 800   $ 800    
Investment, Identifier [Axis]: ATS Workholding, LLC, Secured Debt One November 16,2017          
Schedule of Investments [Line Items]          
Total Rate [1],[10] 5.00%   5.00%    
Investment, Identifier [Axis]: ATS Workholding, LLC, Secured Debt Two | Other controlled investments          
Schedule of Investments [Line Items]          
Total Rate 5.00%   5.00%    
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     (576)    
Amount of Interest, Fees or Dividends Credited to Income     0    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     1,917    
Gross Additions     0    
Gross Reductions     619    
Ending balance $ 1,298   $ 1,298    
Investment, Identifier [Axis]: ATS Workholding, LLC, Secured Debt Two November 16,2017          
Schedule of Investments [Line Items]          
Total Rate [1],[10] 5.00%   5.00%    
Investment, Identifier [Axis]: ATX Networks Corp., Common Stock | Affiliate investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     0    
Amount of Interest, Fees or Dividends Credited to Income     0    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     0    
Gross Additions     0    
Gross Reductions     0    
Ending balance $ 0   $ 0    
Investment, Identifier [Axis]: ATX Networks Corp., Secured Debt | Affiliate investments          
Schedule of Investments [Line Items]          
Total Rate 11.14%   11.14%    
Spread 7.50%   7.50%    
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     403    
Amount of Interest, Fees or Dividends Credited to Income     562    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     7,092    
Gross Additions     631    
Gross Reductions     1,016    
Ending balance $ 6,707   $ 6,707    
Investment, Identifier [Axis]: ATX Networks Corp., Secured Debt One | Affiliate investments          
Schedule of Investments [Line Items]          
Total Rate   10.00%   10.00%  
PIK Rate   10.00%   10.00%  
Amount of Realized Gain/(Loss)       $ 0  
Amount of Unrealized Gain/(Loss)       0  
Amount of Interest, Fees or Dividends Credited to Income       0  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       0  
Gross Additions       1,963  
Gross Reductions       0  
Ending balance   $ 1,963   $ 1,963  
Investment, Identifier [Axis]: ATX Networks Corp., Secured Debt September 01, 2021          
Schedule of Investments [Line Items]          
Total Rate [3],[8] 11.14%   11.14%    
Spread [3],[8] 7.50%   7.50%    
Investment, Identifier [Axis]: ATX Networks Corp., Secured Debt September 01,2021          
Schedule of Investments [Line Items]          
Total Rate [5],[6]         8.50%
Spread [5],[6]         7.50%
Investment, Identifier [Axis]: ATX Networks Corp., Secured Debt Three | Affiliate investments          
Schedule of Investments [Line Items]          
Total Rate   8.75%   8.75%  
Spread   6.25%   6.25%  
PIK Rate   1.50%   1.50%  
Amount of Realized Gain/(Loss)       $ (4,528)  
Amount of Unrealized Gain/(Loss)       1,133  
Amount of Interest, Fees or Dividends Credited to Income       0  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       12,263  
Gross Additions       1,521  
Gross Reductions       13,784  
Ending balance   $ 0   $ 0  
Investment, Identifier [Axis]: ATX Networks Corp., Secured Debt Two | Affiliate investments          
Schedule of Investments [Line Items]          
Total Rate   8.50%   8.50%  
Spread   7.50%   7.50%  
Amount of Realized Gain/(Loss)       $ 0  
Amount of Unrealized Gain/(Loss)       0  
Amount of Interest, Fees or Dividends Credited to Income       0  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       0  
Gross Additions       7,092  
Gross Reductions       0  
Ending balance   $ 7,092   7,092  
Investment, Identifier [Axis]: ATX Networks Corp., Unsecured Debt | Affiliate investments          
Schedule of Investments [Line Items]          
Total Rate 10.00%   10.00%    
PIK Rate 10.00%   10.00%    
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     260    
Amount of Interest, Fees or Dividends Credited to Income     242    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     1,963    
Gross Additions     502    
Gross Reductions     0    
Ending balance $ 2,465   $ 2,465    
Investment, Identifier [Axis]: ATX Networks Corp., Unsecured Debt September 01, 2021          
Schedule of Investments [Line Items]          
Total Rate [8] 10.00%   10.00%    
PIK Rate [8] 10.00%   10.00%    
Investment, Identifier [Axis]: ATX Networks Corp., Unsecured Debt September 01,2021          
Schedule of Investments [Line Items]          
Total Rate [5]         10.00%
PIK Rate [5]         10.00%
Investment, Identifier [Axis]: AVEX Aviation Holdings, LLC, Secured Debt December 15,2021          
Schedule of Investments [Line Items]          
Total Rate [6],[7]         7.50%
Spread [6],[7]         6.50%
Investment, Identifier [Axis]: AVEX Aviation Holdings, LLC, Secured Debt One December 15, 2021          
Schedule of Investments [Line Items]          
Total Rate [1],[3] 10.32%   10.32%    
Spread [1],[3] 7.00%   7.00%    
Investment, Identifier [Axis]: AVEX Aviation Holdings, LLC, Secured Debt Two December 15, 2021          
Schedule of Investments [Line Items]          
Total Rate [1],[3] 10.29%   10.29%    
Spread [1],[3] 7.00%   7.00%    
Investment, Identifier [Axis]: Acousti Engineering Company of Florida, Secured Debt May 26,2021          
Schedule of Investments [Line Items]          
Total Rate [6],[7]         14.00%
Spread [6],[7]         12.50%
Investment, Identifier [Axis]: Acousti Engineering Company of Florida, Secured Debt November 02,2020          
Schedule of Investments [Line Items]          
Total Rate [6],[7]         10.00%
Spread [6],[7]         8.50%
Investment, Identifier [Axis]: Acousti Engineering Company of Florida, Secured Debt One November 02, 2020          
Schedule of Investments [Line Items]          
Total Rate [1],[3] 10.78%   10.78%    
Spread [1],[3] 8.50%   8.50%    
Investment, Identifier [Axis]: Acousti Engineering Company of Florida, Secured Debt Two November 02, 2020          
Schedule of Investments [Line Items]          
Total Rate [1],[3] 10.00%   10.00%    
Spread [1],[3] 8.50%   8.50%    
Investment, Identifier [Axis]: Acousti Engineering Company of Florida, Secured Debt Two May 26 2021          
Schedule of Investments [Line Items]          
Total Rate [1],[3] 14.78%   14.78%    
Spread [1],[3] 12.50%   12.50%    
Investment, Identifier [Axis]: Acumera, Inc., Secured Debt One June 28, 2022          
Schedule of Investments [Line Items]          
Total Rate [1],[3] 12.02%   12.02%    
Spread [1],[3] 9.50%   9.50%    
Investment, Identifier [Axis]: Acumera, Inc., Secured Debt Two June 28, 2022          
Schedule of Investments [Line Items]          
Total Rate [1],[3] 12.02%   12.02%    
Spread [1],[3] 9.50%   9.50%    
Investment, Identifier [Axis]: Adams Publishing Group, LLC, Secured Debt One March 11, 2022          
Schedule of Investments [Line Items]          
Total Rate [1],[3] 12.75%   12.75%    
Spread [1],[3] 6.50%   6.50%    
Investment, Identifier [Axis]: Adams Publishing Group, LLC, Secured Debt Two March 11, 2022          
Schedule of Investments [Line Items]          
Total Rate [1],[3] 10.75%   10.75%    
Spread [1],[3] 7.50%   7.50%    
Investment, Identifier [Axis]: American Health Staffing Group, Inc., Secured Debt November 19,2021          
Schedule of Investments [Line Items]          
Total Rate [6],[7]         7.00%
Spread [6],[7]         6.00%
Investment, Identifier [Axis]: American Health Staffing Group, Inc., Secured Debt One November 19, 2021          
Schedule of Investments [Line Items]          
Spread [1],[3],[4] 7.00%   7.00%    
Investment, Identifier [Axis]: American Health Staffing Group, Inc., Secured Debt Two November 19, 2021          
Schedule of Investments [Line Items]          
Total Rate [1],[3] 8.01%   8.01%    
Spread [1],[3] 7.00%   7.00%    
Investment, Identifier [Axis]: American Nuts, LLC, Secured Debt December 21,2018          
Schedule of Investments [Line Items]          
Total Rate [6],[7]         9.00%
Spread [6],[7]         8.00%
Investment, Identifier [Axis]: American Nuts, LLC, Secured Debt Two March 11, 2022          
Schedule of Investments [Line Items]          
Total Rate [1],[2],[3] 10.98%   10.98%    
Spread [1],[2],[3] 8.75%   8.75%    
Investment, Identifier [Axis]: American Nuts, LLC, Secured Debt one March 11, 2022          
Schedule of Investments [Line Items]          
Total Rate [1],[2],[3] 8.98%   8.98%    
Spread [1],[2],[3] 6.75%   6.75%    
Investment, Identifier [Axis]: American Teleconferencing Services, Ltd., Secured Debt May 19,2016          
Schedule of Investments [Line Items]          
Total Rate [5],[6],[9]         7.50%
Spread [5],[6],[9]         6.50%
Investment, Identifier [Axis]: American Teleconferencing Services, Ltd., Secured Debt One, May 19, 2016          
Schedule of Investments [Line Items]          
Total Rate [3],[8],[10] 7.50%   7.50%    
Spread [3],[8],[10] 6.50%   6.50%    
Investment, Identifier [Axis]: American Teleconferencing Services, Ltd., Secured Debt September 17, 2021          
Schedule of Investments [Line Items]          
Total Rate [8],[10] 7.50%   7.50%    
Spread [8],[10] 6.50%   6.50%    
Investment, Identifier [Axis]: American Teleconferencing Services, Ltd., Secured Debt September 17,2021          
Schedule of Investments [Line Items]          
Total Rate [5],[6],[9],[11]         7.50%
Spread [5],[6],[9],[11]         6.50%
Investment, Identifier [Axis]: Analytical Systems Keco Holdings, LLC, Preferred Member Units One August 16, 2019          
Schedule of Investments [Line Items]          
Total Rate 12.63%   12.63%    
Investment, Identifier [Axis]: Analytical Systems Keco Holdings, LLC, Secured Debt One August 16,2019          
Schedule of Investments [Line Items]          
Spread [3],[4] 10.00%   10.00%    
Investment, Identifier [Axis]: Analytical Systems Keco Holdings, LLC, Secured Debt August 16,2019          
Schedule of Investments [Line Items]          
Total Rate [6]         12.00%
Spread [6]         10.00%
Investment, Identifier [Axis]: Analytical Systems Keco Holdings, LLC, Secured Debt Two August 16, 2019          
Schedule of Investments [Line Items]          
Total Rate [3] 12.63%   12.63%    
Spread [3] 10.00%   10.00%    
Investment, Identifier [Axis]: ArborWorks, LLC, Secured Debt November 09,2021          
Schedule of Investments [Line Items]          
Total Rate [6],[7]         8.00%
Spread [6],[7]         7.00%
Investment, Identifier [Axis]: ArborWorks, LLC, Secured Debt One November 09, 2021          
Schedule of Investments [Line Items]          
Total Rate [1],[3] 9.97%   9.97%    
Spread [1],[3] 7.00%   7.00%    
Investment, Identifier [Axis]: ArborWorks, LLC, Secured Debt Two November 09, 2021          
Schedule of Investments [Line Items]          
Total Rate [1],[3] 9.87%   9.87%    
Spread [1],[3] 7.00%   7.00%    
Investment, Identifier [Axis]: Archer Systems, LLC, Secured Debt One August 11, 2022          
Schedule of Investments [Line Items]          
Total Rate [1],[2],[3] 9.65%   9.65%    
Spread [1],[2],[3] 6.50%   6.50%    
Investment, Identifier [Axis]: Archer Systems, LLC, Secured Debt Two August 11, 2022          
Schedule of Investments [Line Items]          
Total Rate [1],[2],[3] 8.91%   8.91%    
Spread [1],[2],[3] 6.50%   6.50%    
Investment, Identifier [Axis]: Arrow International, Inc, Secured Debt December 21, 2020          
Schedule of Investments [Line Items]          
Total Rate [1],[3],[12] 11.96%   11.96%    
Spread [1],[3],[12] 5.61%   5.61%    
Investment, Identifier [Axis]: Arrow International, Inc, Secured Debt December 21,2020          
Schedule of Investments [Line Items]          
Total Rate [6],[7],[13]         9.18%
Spread [6],[7],[13]         7.93%
Investment, Identifier [Axis]: BBB Tank Services, LLC, Member Units | Affiliate investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     $ 0 0  
Amount of Unrealized Gain/(Loss)     0 (280)  
Amount of Interest, Fees or Dividends Credited to Income     0 0  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     0 280  
Gross Additions     0 0  
Gross Reductions     0 280  
Ending balance $ 0 $ 0 $ 0 $ 0  
Investment, Identifier [Axis]: BBB Tank Services, LLC, Preferred Stock (non-voting) | Affiliate investments          
Schedule of Investments [Line Items]          
Total Rate 15.00% 15.00% 15.00% 15.00%  
PIK Rate 15.00% 15.00% 15.00% 15.00%  
Amount of Realized Gain/(Loss)     $ 0 $ 0  
Amount of Unrealized Gain/(Loss)     0 (162)  
Amount of Interest, Fees or Dividends Credited to Income     0 11  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     0 151  
Gross Additions     0 11  
Gross Reductions     0 162  
Ending balance $ 0 $ 0 $ 0 $ 0  
Investment, Identifier [Axis]: BBB Tank Services, LLC, Preferred Stock (non-voting) December 17, 2018          
Schedule of Investments [Line Items]          
Total Rate 15.00%   15.00%    
PIK Rate 15.00%   15.00%    
Investment, Identifier [Axis]: BBB Tank Services, LLC, Preferred Stock (non-voting) December 17,2018          
Schedule of Investments [Line Items]          
Total Rate [14]         15.00%
PIK Rate [14]         15.00%
Investment, Identifier [Axis]: BBB Tank Services, LLC, Unsecured Debt | Affiliate investments          
Schedule of Investments [Line Items]          
Total Rate   12.00%   12.00%  
Spread   11.00%   11.00%  
Amount of Realized Gain/(Loss)       $ 0  
Amount of Unrealized Gain/(Loss)       (1,000)  
Amount of Interest, Fees or Dividends Credited to Income       464  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       4,722  
Gross Additions       27  
Gross Reductions       1,001  
Ending balance   $ 3,748   3,748  
Investment, Identifier [Axis]: BBB Tank Services, LLC, Unsecured Debt April 08,2016          
Schedule of Investments [Line Items]          
Total Rate [6],[11]         12.00%
Spread [6],[11]         11.00%
Investment, Identifier [Axis]: BBB Tank Services, LLC, Unsecured Debt One | Affiliate investments          
Schedule of Investments [Line Items]          
Total Rate 13.56%   13.56%    
Spread 11.00%   11.00%    
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     0    
Amount of Interest, Fees or Dividends Credited to Income     75    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     800    
Gross Additions     0    
Gross Reductions     0    
Ending balance $ 800   $ 800    
Investment, Identifier [Axis]: BBB Tank Services, LLC, Unsecured Debt One April 08, 2016          
Schedule of Investments [Line Items]          
Total Rate [3],[15] 13.56%   13.56%    
Spread [3],[15] 11.00%   11.00%    
Investment, Identifier [Axis]: BBB Tank Services, LLC, Unsecured Debt Two | Affiliate investments          
Schedule of Investments [Line Items]          
Total Rate 13.56%   13.56%    
Spread 11.00%   11.00%    
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     (209)    
Amount of Interest, Fees or Dividends Credited to Income     377    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     1,707    
Gross Additions     0    
Gross Reductions     209    
Ending balance $ 1,498   $ 1,498    
Investment, Identifier [Axis]: BBB Tank Services, LLC, Unsecured Debt Two April 08, 2016          
Schedule of Investments [Line Items]          
Total Rate [3],[15] 13.56%   13.56%    
Spread [3],[15] 11.00%   11.00%    
Investment, Identifier [Axis]: Barfly Ventures, LLC, Member Units | Other controlled investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     1,390    
Amount of Interest, Fees or Dividends Credited to Income     0    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     1,930    
Gross Additions     1,390    
Gross Reductions     0    
Ending balance $ 3,320   $ 3,320    
Investment, Identifier [Axis]: Barfly Ventures, LLC, Member Units | Other controlled investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)       0  
Amount of Unrealized Gain/(Loss)       346  
Amount of Interest, Fees or Dividends Credited to Income       0  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       1,584  
Gross Additions       346  
Gross Reductions       0  
Ending balance   $ 1,930   $ 1,930  
Investment, Identifier [Axis]: Barfly Ventures, LLC, Secured Debt | Other controlled investments          
Schedule of Investments [Line Items]          
Total Rate 7.00% 7.00% 7.00% 7.00%  
Amount of Realized Gain/(Loss)     $ 0 $ 0  
Amount of Unrealized Gain/(Loss)     0 0  
Amount of Interest, Fees or Dividends Credited to Income     38 58  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     710 343  
Gross Additions     1 367  
Gross Reductions     0 0  
Ending balance $ 711 $ 710 $ 711 710  
Investment, Identifier [Axis]: Barfly Ventures, LLC, Secured Debt October 15, 2020          
Schedule of Investments [Line Items]          
Total Rate [1] 7.00%   7.00%    
Investment, Identifier [Axis]: Barfly Ventures, LLC, Secured Debt October 15,2020          
Schedule of Investments [Line Items]          
Total Rate [7]         7.00%
Investment, Identifier [Axis]: Batjer TopCo, LLC, Preferred Stock | Other controlled investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     0    
Amount of Interest, Fees or Dividends Credited to Income     0    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     0    
Gross Additions     4,095    
Gross Reductions     0    
Ending balance $ 4,095   4,095    
Investment, Identifier [Axis]: Batjer TopCo, LLC, Secured Debt One | Other controlled investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     0    
Amount of Unrealized Gain/(Loss)     0    
Amount of Interest, Fees or Dividends Credited to Income     4    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     0    
Gross Additions     451    
Gross Reductions     459    
Ending balance $ (8)   $ (8)    
Investment, Identifier [Axis]: Batjer TopCo, LLC, Secured Debt Three | Other controlled investments          
Schedule of Investments [Line Items]          
Total Rate 11.00%   11.00%    
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     0    
Amount of Interest, Fees or Dividends Credited to Income     824    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     0    
Gross Additions     10,927    
Gross Reductions     0    
Ending balance $ 10,927   $ 10,927    
Investment, Identifier [Axis]: Batjer TopCo, LLC, Secured Debt Three March 7,2022          
Schedule of Investments [Line Items]          
Total Rate 11.00%   11.00%    
Investment, Identifier [Axis]: Batjer TopCo, LLC, Secured Debt Two | Other controlled investments          
Schedule of Investments [Line Items]          
Total Rate 11.00%   11.00%    
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     0    
Amount of Interest, Fees or Dividends Credited to Income     0    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     0    
Gross Additions     0    
Gross Reductions     0    
Ending balance $ 0   $ 0    
Investment, Identifier [Axis]: Berry Aviation, Inc., Preferred Member Units July 06,2018          
Schedule of Investments [Line Items]          
Total Rate [7],[16]         8.00%
PIK Rate [7],[16]         8.00%
Investment, Identifier [Axis]: Berry Aviation, Inc., Preferred Member Units November 12,2019          
Schedule of Investments [Line Items]          
Total Rate [7],[14],[16]         16.00%
PIK Rate [7],[14],[16]         16.00%
Investment, Identifier [Axis]: Berry Aviation, Inc., Preferred Member Units One July 06, 2018          
Schedule of Investments [Line Items]          
Total Rate [1],[17],[18] 8.00%   8.00%    
PIK Rate [1],[17],[18] 8.00%   8.00%    
Investment, Identifier [Axis]: Berry Aviation, Inc., Preferred Member Units Two November 12, 2019          
Schedule of Investments [Line Items]          
Total Rate [1],[17],[18] 16.00%   16.00%    
PIK Rate [1],[17],[18] 16.00%   16.00%    
Investment, Identifier [Axis]: Berry Aviation, Inc., Secured Debt July 06, 2018          
Schedule of Investments [Line Items]          
Total Rate [1] 12.00%   12.00%    
Spread [1] 10.50%   10.50%    
PIK Rate [1] 1.50%   1.50%    
Investment, Identifier [Axis]: Berry Aviation, Inc., Secured Debt July 06,2018          
Schedule of Investments [Line Items]          
Total Rate [7]         12.00%
PIK Rate [7]         1.50%
Investment, Identifier [Axis]: Bettercloud, Inc., Secured Debt One June 30, 2022          
Schedule of Investments [Line Items]          
Spread [1],[2],[3],[4] 6.00%   6.00%    
Investment, Identifier [Axis]: Bettercloud, Inc., Secured Debt Two June 30, 2022          
Schedule of Investments [Line Items]          
Total Rate [1],[2],[3] 9.78%   9.78%    
Spread [1],[2],[3] 6.75%   6.75%    
PIK Rate [1],[2],[3] 5.75%   5.75%    
Investment, Identifier [Axis]: Binswanger Enterprises, LLC, Secured Debt March 10,2017          
Schedule of Investments [Line Items]          
Total Rate [6],[7]         9.50%
Spread [6],[7]         8.50%
Investment, Identifier [Axis]: Bluestem Brands, Inc, Secured Debt August 28, 2020          
Schedule of Investments [Line Items]          
Total Rate [3],[8] 11.29%   11.29%    
Spread [3],[8] 8.50%   8.50%    
Investment, Identifier [Axis]: Bluestem Brands, Inc., Secured Debt August 28,2020          
Schedule of Investments [Line Items]          
Total Rate [5],[6]         10.00%
Spread [5],[6]         8.50%
Investment, Identifier [Axis]: Boccella Precast Products LLC, Member Units | Affiliate investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     $ 0 0  
Amount of Unrealized Gain/(Loss)     (1,510) (1,210)  
Amount of Interest, Fees or Dividends Credited to Income     73 379  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     4,830 6,040  
Gross Additions     0 0  
Gross Reductions     1,510 1,210  
Ending balance $ 3,320 $ 4,830 $ 3,320 $ 4,830  
Investment, Identifier [Axis]: Boccella Precast Products LLC, Secured Debt | Affiliate investments          
Schedule of Investments [Line Items]          
Total Rate   10.00%   10.00%  
Amount of Realized Gain/(Loss)       $ 0  
Amount of Unrealized Gain/(Loss)       0  
Amount of Interest, Fees or Dividends Credited to Income       1  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       0  
Gross Additions       320  
Gross Reductions       0  
Ending balance   $ 320   $ 320  
Investment, Identifier [Axis]: Boccella Precast Products LLC, Secured Debt | Affiliate investments          
Schedule of Investments [Line Items]          
Total Rate 10.00%   10.00%    
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     0    
Amount of Interest, Fees or Dividends Credited to Income     24    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     320    
Gross Additions     0    
Gross Reductions     0    
Ending balance $ 320   $ 320    
Investment, Identifier [Axis]: Boccella Precast Products LLC, Secured Debt September 23, 2021          
Schedule of Investments [Line Items]          
Total Rate 10.00%   10.00%    
Investment, Identifier [Axis]: Boccella Precast Products LLC, Secured Debt September 23,2021          
Schedule of Investments [Line Items]          
Total Rate         10.00%
Investment, Identifier [Axis]: Bolder Panther Group, LLC, Class A Preferred Member Units | Other controlled investments          
Schedule of Investments [Line Items]          
Total Rate   14.00%   14.00%  
Amount of Realized Gain/(Loss)       $ 0  
Amount of Unrealized Gain/(Loss)       0  
Amount of Interest, Fees or Dividends Credited to Income       1,067  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       10,194  
Gross Additions       0  
Gross Reductions       0  
Ending balance   $ 10,194   $ 10,194  
Investment, Identifier [Axis]: Bolder Panther Group, LLC, Class A Preferred Member Units December 31,2020          
Schedule of Investments [Line Items]          
Total Rate [14]         14.00%
Investment, Identifier [Axis]: Bolder Panther Group, LLC, Class B Preferred Member Units | Other controlled investments          
Schedule of Investments [Line Items]          
Total Rate 8.00% 8.00% 8.00% 8.00%  
Amount of Realized Gain/(Loss)     $ 0 $ 0  
Amount of Unrealized Gain/(Loss)     3,840 6,310  
Amount of Interest, Fees or Dividends Credited to Income     558 2,087  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     23,170 14,000  
Gross Additions     3,840 6,310  
Gross Reductions     0 0  
Ending balance $ 27,010 $ 20,310 $ 27,010 $ 20,310  
Investment, Identifier [Axis]: Bolder Panther Group, LLC, Class B Preferred Member Units December 31,2020          
Schedule of Investments [Line Items]          
Total Rate 8.00% [17]   8.00% [17]   8.00% [14]
Investment, Identifier [Axis]: Bolder Panther Group, LLC, Secured Debt December 31,2020          
Schedule of Investments [Line Items]          
Total Rate [6]         10.50%
Spread [6]         9.00%
Investment, Identifier [Axis]: Bolder Panther Group, LLC, Secured Debt One | Other controlled investments          
Schedule of Investments [Line Items]          
Total Rate   10.50%   10.50%  
Spread 8.00% 9.00% 8.00% 9.00%  
Amount of Realized Gain/(Loss)     $ 0 $ 0  
Amount of Unrealized Gain/(Loss)     0 329  
Amount of Interest, Fees or Dividends Credited to Income     19 2,582  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     0 27,225  
Gross Additions     0 11,775  
Gross Reductions     0 0  
Ending balance $ 0 $ 39,000 $ 0 $ 39,000  
Investment, Identifier [Axis]: Bolder Panther Group, LLC, Secured Debt One December 31,2020          
Schedule of Investments [Line Items]          
Spread [3],[4] 8.00%   8.00%    
Investment, Identifier [Axis]: Bolder Panther Group, LLC, Secured Debt Two | Other controlled investments          
Schedule of Investments [Line Items]          
Total Rate 12.63% 9.50% 12.63% 9.50%  
Spread 10.00% 8.00% 10.00% 8.00%  
Amount of Realized Gain/(Loss)     $ 0 $ 0  
Amount of Unrealized Gain/(Loss)     266 0  
Amount of Interest, Fees or Dividends Credited to Income     5,780 36  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     39,000 0  
Gross Additions     60,194 500  
Gross Reductions     0 500  
Ending balance $ 99,194 $ 0 $ 99,194 0  
Investment, Identifier [Axis]: Bolder Panther Group, LLC, Secured Debt Two December 31,2020          
Schedule of Investments [Line Items]          
Total Rate [3] 12.63%   12.63%    
Spread [3] 10.00%   10.00%    
Investment, Identifier [Axis]: Bond-Coat, Inc., Common Stock | Other controlled investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)       (2,320)  
Amount of Unrealized Gain/(Loss)       4,310  
Amount of Interest, Fees or Dividends Credited to Income       0  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       2,040  
Gross Additions       4,310  
Gross Reductions       6,350  
Ending balance   0   0  
Investment, Identifier [Axis]: Brainworks Software, LLC, Secured Debt August 12,2014          
Schedule of Investments [Line Items]          
Total Rate [6],[7],[9],[11]         12.50%
Spread [6],[7],[9],[11]         9.25%
Investment, Identifier [Axis]: Brainworks Software, LLC, Secured Debt One August 12, 2014          
Schedule of Investments [Line Items]          
Total Rate [1],[3],[10],[15] 12.50%   12.50%    
Spread [1],[3],[10],[15] 9.25%   9.25%    
Investment, Identifier [Axis]: Brainworks Software, LLC, Secured Debt Two August 12, 2014          
Schedule of Investments [Line Items]          
Total Rate [1],[3],[10],[15] 12.50%   12.50%    
Spread [1],[3],[10],[15] 9.25%   9.25%    
Investment, Identifier [Axis]: Brewer Crane Holdings, LLC, Preferred Member Units | Majority-owned investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     (2,040)    
Amount of Interest, Fees or Dividends Credited to Income     795    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     7,710    
Gross Additions     0    
Gross Reductions     2,040    
Ending balance $ 5,670   $ 5,670    
Investment, Identifier [Axis]: Brewer Crane Holdings, LLC, Preferred Member Units | Other controlled investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)       0  
Amount of Unrealized Gain/(Loss)       (1,570)  
Amount of Interest, Fees or Dividends Credited to Income       397  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       5,850  
Gross Additions       0  
Gross Reductions       1,570  
Ending balance   $ 4,280   $ 4,280  
Investment, Identifier [Axis]: Brewer Crane Holdings, LLC, Secured Debt | Majority-owned investments          
Schedule of Investments [Line Items]          
Total Rate 12.56%   12.56%    
Spread 10.00%   10.00%    
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     0    
Amount of Interest, Fees or Dividends Credited to Income     649    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     8,037    
Gross Additions     19    
Gross Reductions     1,972    
Ending balance $ 6,084   $ 6,084    
Investment, Identifier [Axis]: Brewer Crane Holdings, LLC, Secured Debt | Other controlled investments          
Schedule of Investments [Line Items]          
Total Rate   11.00%   11.00%  
Spread   10.00%   10.00%  
Amount of Realized Gain/(Loss)       $ 0  
Amount of Unrealized Gain/(Loss)       0  
Amount of Interest, Fees or Dividends Credited to Income       708  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       8,513  
Gross Additions       15  
Gross Reductions       372  
Ending balance   $ 8,156   8,156  
Investment, Identifier [Axis]: Brewer Crane Holdings, LLC, Secured Debt January 09,2018          
Schedule of Investments [Line Items]          
Total Rate [6]         11.00%
Spread [6]         10.00%
Investment, Identifier [Axis]: Brewer Crane Holdings, LLC, Secured Debt January 9, 2018          
Schedule of Investments [Line Items]          
Total Rate [3] 12.56%   12.56%    
Spread 10.00%   10.00%    
Investment, Identifier [Axis]: Bridge Capital Solutions Corporation, Preferred Member Units | Other controlled investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     $ 0 0  
Amount of Unrealized Gain/(Loss)     0 0  
Amount of Interest, Fees or Dividends Credited to Income     75 75  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     1,000 1,000  
Gross Additions     0 0  
Gross Reductions     0 0  
Ending balance $ 1,000 $ 1,000 $ 1,000 $ 1,000  
Investment, Identifier [Axis]: Bridge Capital Solutions Corporation, Secured Debt July 25, 2016          
Schedule of Investments [Line Items]          
Total Rate [16]         13.00%
Investment, Identifier [Axis]: Bridge Capital Solutions Corporation, Secured Debt July 25,2016          
Schedule of Investments [Line Items]          
Total Rate         13.00%
Investment, Identifier [Axis]: Bridge Capital Solutions Corporation, Secured Debt One | Other controlled investments          
Schedule of Investments [Line Items]          
Total Rate 13.00% 13.00% 13.00% 13.00%  
Amount of Realized Gain/(Loss)     $ 0 $ 0  
Amount of Unrealized Gain/(Loss)     0 0  
Amount of Interest, Fees or Dividends Credited to Income     869 100  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     8,813 998  
Gross Additions     0 2  
Gross Reductions     0 0  
Ending balance $ 8,813 $ 1,000 $ 8,813 $ 1,000  
Investment, Identifier [Axis]: Bridge Capital Solutions Corporation, Secured Debt One July 25, 2016          
Schedule of Investments [Line Items]          
Total Rate 13.00%   13.00%    
Investment, Identifier [Axis]: Bridge Capital Solutions Corporation, Secured Debt Two | Other controlled investments          
Schedule of Investments [Line Items]          
Total Rate 13.00% 13.00% 13.00% 13.00%  
Amount of Realized Gain/(Loss)     $ 0 $ 0  
Amount of Unrealized Gain/(Loss)     0 0  
Amount of Interest, Fees or Dividends Credited to Income     99 1,279  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     1,000 8,403  
Gross Additions     0 410  
Gross Reductions     0 0  
Ending balance $ 1,000 $ 8,813 $ 1,000 8,813  
Investment, Identifier [Axis]: Bridge Capital Solutions Corporation, Secured Debt Two July 25, 2016          
Schedule of Investments [Line Items]          
Total Rate [18] 13.00%   13.00%    
Investment, Identifier [Axis]: Bridge Capital Solutions Corporation, Warrants | Other controlled investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)       0  
Amount of Unrealized Gain/(Loss)       840  
Amount of Interest, Fees or Dividends Credited to Income       0  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       3,220  
Gross Additions       840  
Gross Reductions       0  
Ending balance   4,060   4,060  
Investment, Identifier [Axis]: Bridge Capital Solutions Corporation, Warrants One | Other controlled investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     83    
Amount of Interest, Fees or Dividends Credited to Income     0    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     1,712    
Gross Additions     83    
Gross Reductions     0    
Ending balance $ 1,795   1,795    
Investment, Identifier [Axis]: Bridge Capital Solutions Corporation, Warrants Two | Other controlled investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     0    
Amount of Unrealized Gain/(Loss)     117    
Amount of Interest, Fees or Dividends Credited to Income     0    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     2,348    
Gross Additions     117    
Gross Reductions     0    
Ending balance $ 2,465   $ 2,465    
Investment, Identifier [Axis]: Brightwood Capital Fund Investments - Fund V, LP Interests (Brightwood Capital Fund V, LP) | Affiliate investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)       0  
Amount of Unrealized Gain/(Loss)       0  
Amount of Interest, Fees or Dividends Credited to Income       0  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       0  
Gross Additions       1,000  
Gross Reductions       0  
Ending balance   $ 1,000   $ 1,000  
Investment, Identifier [Axis]: Buca C, LLC, Preferred Member Units | Affiliate investments          
Schedule of Investments [Line Items]          
Total Rate 6.00%   6.00%    
PIK Rate 6.00%   6.00%    
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     0    
Amount of Interest, Fees or Dividends Credited to Income     0    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     0    
Gross Additions     0    
Gross Reductions     0    
Ending balance $ 0   $ 0    
Investment, Identifier [Axis]: Buca C, LLC, Preferred Member Units June 30, 2015          
Schedule of Investments [Line Items]          
Total Rate 6.00%   6.00%    
PIK Rate 6.00%   6.00%    
Investment, Identifier [Axis]: Buca C, LLC, Preferred Member Units June 30,2015          
Schedule of Investments [Line Items]          
Total Rate         6.00%
PIK Rate         6.00%
Investment, Identifier [Axis]: Buca C, LLC, Secured Debt | Affiliate investments          
Schedule of Investments [Line Items]          
Total Rate 9.00% 10.25% 9.00% 10.25%  
Spread   9.25%   9.25%  
Amount of Realized Gain/(Loss)     $ 0 $ 0  
Amount of Unrealized Gain/(Loss)     1,604 (373)  
Amount of Interest, Fees or Dividends Credited to Income     1,488 1,264  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     14,370 14,256  
Gross Additions     1,602 487  
Gross Reductions     1,966 373  
Ending balance $ 14,006 $ 14,370 $ 14,006 14,370  
Investment, Identifier [Axis]: Buca C, LLC, Secured Debt June 30, 2015          
Schedule of Investments [Line Items]          
Total Rate 9.00%   9.00%    
Investment, Identifier [Axis]: Buca C, LLC, Secured Debt June 30,2015          
Schedule of Investments [Line Items]          
Total Rate [6],[11]         10.25%
Spread [6],[11]         9.25%
Investment, Identifier [Axis]: Burning Glass Intermediate Holding Company, Inc., Secured Debt June 14,2021          
Schedule of Investments [Line Items]          
Total Rate [6],[7]         6.00%
Spread [6],[7]         5.00%
Investment, Identifier [Axis]: Burning Glass Intermediate Holding Company, Inc., Secured Debt One June 14, 2021          
Schedule of Investments [Line Items]          
Total Rate [1],[3] 7.52%   7.52%    
Spread [1],[3] 5.00%   5.00%    
Investment, Identifier [Axis]: Burning Glass Intermediate Holding Company, Inc., Secured Debt One June 14,2021          
Schedule of Investments [Line Items]          
Total Rate [6],[7]         6.00%
Spread [6],[7]         5.00%
Investment, Identifier [Axis]: Burning Glass Intermediate Holding Company, Inc., Secured Debt Two June 14, 2021          
Schedule of Investments [Line Items]          
Total Rate [1],[3] 7.52%   7.52%    
Spread [1],[3] 5.00%   5.00%    
Investment, Identifier [Axis]: CAI Software LLC, Member Units | Affiliate investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)       0  
Amount of Unrealized Gain/(Loss)       7,321  
Amount of Interest, Fees or Dividends Credited to Income       1,900  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       7,190  
Gross Additions       7,321  
Gross Reductions       1,921  
Ending balance   $ 12,590   $ 12,590  
Investment, Identifier [Axis]: CAI Software LLC, Secured Debt | Affiliate investments          
Schedule of Investments [Line Items]          
Total Rate   12.50%   12.50%  
Amount of Realized Gain/(Loss)       $ 0  
Amount of Unrealized Gain/(Loss)       (1)  
Amount of Interest, Fees or Dividends Credited to Income       5,547  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       47,474  
Gross Additions       23,601  
Gross Reductions       4,474  
Ending balance   $ 66,601   66,601  
Investment, Identifier [Axis]: CBT Nuggets, LLC, Member Units | Other controlled investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     (2,370)    
Amount of Interest, Fees or Dividends Credited to Income     2,471    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     50,620    
Gross Additions     0    
Gross Reductions     2,370    
Ending balance $ 48,250   48,250    
Investment, Identifier [Axis]: CBT Nuggets, LLC, Member Units | Other controlled investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)       0  
Amount of Unrealized Gain/(Loss)       6,540  
Amount of Interest, Fees or Dividends Credited to Income       1,901  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       46,080  
Gross Additions       6,540  
Gross Reductions       0  
Ending balance   52,620   52,620  
Investment, Identifier [Axis]: CMS Minerals Investments, Member Units | Majority-owned investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     0 0  
Amount of Unrealized Gain/(Loss)     331 453  
Amount of Interest, Fees or Dividends Credited to Income     150 22  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     1,974 1,624  
Gross Additions     331 454  
Gross Reductions     415 195  
Ending balance $ 1,890 1,883 $ 1,890 1,883  
Investment, Identifier [Axis]: Cadence Aerospace LLC, Secured Debt November 14, 2017          
Schedule of Investments [Line Items]          
Total Rate [1],[3],[19] 11.31%   11.31%    
Spread [1],[3],[19] 8.50%   8.50%    
PIK Rate [1],[3],[19] 0.13%   0.13%    
Investment, Identifier [Axis]: Cadence Aerospace LLC, Secured Debt November 14, 2017          
Schedule of Investments [Line Items]          
PIK Rate 2.00%   2.00%    
Investment, Identifier [Axis]: Cadence Aerospace LLC, Secured Debt November 14,2017          
Schedule of Investments [Line Items]          
Total Rate [7],[20]         9.28%
PIK Rate [7],[20]         0.22%
Investment, Identifier [Axis]: Café Brazil, LLC, Member Units | Majority-owned investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     (200)    
Amount of Interest, Fees or Dividends Credited to Income     178    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     2,570    
Gross Additions     0    
Gross Reductions     200    
Ending balance $ 2,370   2,370    
Investment, Identifier [Axis]: Café Brazil, LLC, Member Units | Majority-owned investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)       0  
Amount of Unrealized Gain/(Loss)       540  
Amount of Interest, Fees or Dividends Credited to Income       470  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       2,030  
Gross Additions       540  
Gross Reductions       0  
Ending balance   2,570   2,570  
Investment, Identifier [Axis]: California Splendor Holdings LLC, Preferred Member Units July 31,2019          
Schedule of Investments [Line Items]          
Total Rate [14]         15.00%
PIK Rate [14]         15.00%
Investment, Identifier [Axis]: California Splendor Holdings LLC, Preferred Member Units One | Majority-owned investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     0 0  
Amount of Unrealized Gain/(Loss)     7,750 4,564  
Amount of Interest, Fees or Dividends Credited to Income     188 188  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     13,275 6,241  
Gross Additions     7,750 4,564  
Gross Reductions     0 0  
Ending balance $ 21,025 $ 10,805 $ 21,025 $ 10,805  
Investment, Identifier [Axis]: California Splendor Holdings LLC, Preferred Member Units Two | Majority-owned investments          
Schedule of Investments [Line Items]          
Total Rate 15.00% 15.00% 15.00% 15.00%  
PIK Rate 15.00% 15.00% 15.00% 15.00%  
Amount of Realized Gain/(Loss)     $ 0 $ 0  
Amount of Unrealized Gain/(Loss)     0 0  
Amount of Interest, Fees or Dividends Credited to Income     792 939  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     9,510 8,255  
Gross Additions     792 939  
Gross Reductions     6,449 0  
Ending balance $ 3,853 $ 9,194 $ 3,853 $ 9,194  
Investment, Identifier [Axis]: California Splendor Holdings LLC, Preferred Member Units Two March 30,2018          
Schedule of Investments [Line Items]          
Total Rate [17] 15.00%   15.00%    
PIK Rate [17] 15.00%   15.00%    
Investment, Identifier [Axis]: California Splendor Holdings LLC, Secured Debt | Majority-owned investments          
Schedule of Investments [Line Items]          
Total Rate 12.38% 11.00% 12.38% 11.00%  
Spread 10.00% 10.00% 10.00% 10.00%  
Amount of Realized Gain/(Loss)     $ 0 $ 0  
Amount of Unrealized Gain/(Loss)     52 36  
Amount of Interest, Fees or Dividends Credited to Income     2,467 2,579  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     27,915 35,832  
Gross Additions     85 196  
Gross Reductions     0 8,129  
Ending balance $ 28,000 $ 27,899 $ 28,000 27,899  
Investment, Identifier [Axis]: California Splendor Holdings LLC, Secured Debt March 30,2018          
Schedule of Investments [Line Items]          
Total Rate 12.38% [3]   12.38% [3]   11.00% [6]
Spread 10.00% [3]   10.00% [3]   10.00% [6]
Investment, Identifier [Axis]: Camin Cargo Control, Inc., Secured Debt June 14, 2021          
Schedule of Investments [Line Items]          
Total Rate [3],[8] 9.62%   9.62%    
Spread [3],[8] 6.50%   6.50%    
Investment, Identifier [Axis]: Camin Cargo Control, Inc., Secured Debt June 14,2021          
Schedule of Investments [Line Items]          
Total Rate [5],[6]         7.50%
Spread [5],[6]         6.50%
Investment, Identifier [Axis]: Career Team Holdings, LLC, Common Stock | Affiliate investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     0    
Amount of Interest, Fees or Dividends Credited to Income     0    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     4,500    
Gross Additions     0    
Gross Reductions     0    
Ending balance $ 4,500   $ 4,500    
Investment, Identifier [Axis]: Career Team Holdings, LLC, Secured Debt December 17,2021          
Schedule of Investments [Line Items]          
Total Rate         12.50%
Investment, Identifier [Axis]: Career Team Holdings, LLC, Secured Debt One | Affiliate investments          
Schedule of Investments [Line Items]          
Total Rate 8.63%   8.63%    
Spread 6.00%   6.00%    
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     0    
Amount of Interest, Fees or Dividends Credited to Income     5    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     0    
Gross Additions     0    
Gross Reductions     0    
Ending balance $ 0   $ 0    
Investment, Identifier [Axis]: Career Team Holdings, LLC, Secured Debt One December 17, 2021          
Schedule of Investments [Line Items]          
Spread [3],[4] 6.00%   6.00%    
Investment, Identifier [Axis]: Career Team Holdings, LLC, Secured Debt Two | Affiliate investments          
Schedule of Investments [Line Items]          
Total Rate 12.50%   12.50%    
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     0    
Amount of Interest, Fees or Dividends Credited to Income     1,950    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     20,050    
Gross Additions     30    
Gross Reductions     0    
Ending balance $ 20,080   $ 20,080    
Investment, Identifier [Axis]: Career Team Holdings, LLC, Secured Debt Two December 17, 2021          
Schedule of Investments [Line Items]          
Total Rate 12.50%   12.50%    
Investment, Identifier [Axis]: CaseWorthy, Inc., Secured Debt One May 18, 2022          
Schedule of Investments [Line Items]          
Spread [1],[3],[4] 5.25%   5.25%    
Investment, Identifier [Axis]: CaseWorthy, Inc., Secured Debt Three May 18, 2022          
Schedule of Investments [Line Items]          
Total Rate [1],[3] 8.26%   8.26%    
Spread [1],[3] 5.25%   5.25%    
Investment, Identifier [Axis]: CaseWorthy, Inc., Secured Debt Two May 18, 2022          
Schedule of Investments [Line Items]          
Spread [1],[3],[4] 5.25%   5.25%    
Investment, Identifier [Axis]: Centre Technologies Holdings, LLC, Preferred Member Units | Other controlled investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     2,038    
Amount of Interest, Fees or Dividends Credited to Income     90    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     5,840    
Gross Additions     2,320    
Gross Reductions     0    
Ending balance $ 8,160   $ 8,160    
Investment, Identifier [Axis]: Centre Technologies Holdings, LLC, Preferred Member Units | Other controlled investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)       0  
Amount of Unrealized Gain/(Loss)       (320)  
Amount of Interest, Fees or Dividends Credited to Income       90  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       6,160  
Gross Additions       0  
Gross Reductions       320  
Ending balance   $ 5,840   $ 5,840  
Investment, Identifier [Axis]: Centre Technologies Holdings, LLC, Secured Debt | Other controlled investments          
Schedule of Investments [Line Items]          
Total Rate   12.00%   12.00%  
Spread   10.00%   10.00%  
Amount of Realized Gain/(Loss)       $ 0  
Amount of Unrealized Gain/(Loss)       0  
Amount of Interest, Fees or Dividends Credited to Income       969  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       11,549  
Gross Additions       28  
Gross Reductions       2,059  
Ending balance   $ 9,518   9,518  
Investment, Identifier [Axis]: Centre Technologies Holdings, LLC, Secured Debt One | Other controlled investments          
Schedule of Investments [Line Items]          
Spread 9.00%   9.00%    
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     0    
Amount of Interest, Fees or Dividends Credited to Income     25    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     0    
Gross Additions     1,440    
Gross Reductions     1,440    
Ending balance $ 0   $ 0    
Investment, Identifier [Axis]: Centre Technologies Holdings, LLC, Secured Debt Two | Other controlled investments          
Schedule of Investments [Line Items]          
Total Rate 11.63%   11.63%    
Spread 9.00%   9.00%    
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     507    
Amount of Interest, Fees or Dividends Credited to Income     1,271    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     8,864    
Gross Additions     6,470    
Gross Reductions     387    
Ending balance $ 14,947   $ 14,947    
Investment, Identifier [Axis]: Centre Technologies Holdings, LLC, Secured Debt January 04,2019          
Schedule of Investments [Line Items]          
Total Rate [6]         12.00%
Spread [6]         10.00%
Investment, Identifier [Axis]: Centre Technologies Holdings, LLC, Secured Debt One January 4, 2019          
Schedule of Investments [Line Items]          
Spread [3],[4] 9.00%   9.00%    
Investment, Identifier [Axis]: Centre Technologies Holdings, LLC, Secured Debt Two January 4, 2019          
Schedule of Investments [Line Items]          
Total Rate [3] 11.63%   11.63%    
Spread [3] 9.00%   9.00%    
Investment, Identifier [Axis]: Chamberlin Holding LLC, Member Units One | Other controlled investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     $ 0 0  
Amount of Unrealized Gain/(Loss)     (1,810) 160  
Amount of Interest, Fees or Dividends Credited to Income     1,335 51  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     24,140 1,270  
Gross Additions     0 160  
Gross Reductions     1,810 0  
Ending balance $ 22,330 1,430 22,330 1,430  
Investment, Identifier [Axis]: Chamberlin Holding LLC, Member Units Two | Other controlled investments          
Schedule of Investments [Line Items]          
Amount of Realized Gain/(Loss)     0 0  
Amount of Unrealized Gain/(Loss)     0 (3,930)  
Amount of Interest, Fees or Dividends Credited to Income     55 3,707  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     1,540 28,070  
Gross Additions     451 0  
Gross Reductions     0 3,930  
Ending balance $ 1,991 $ 24,140 $ 1,991 $ 24,140  
Investment, Identifier [Axis]: Chamberlin Holding LLC, Secured Debt | Other controlled investments          
Schedule of Investments [Line Items]          
Total Rate   9.00%   9.00%  
Spread   8.00%   8.00%  
Amount of Realized Gain/(Loss)       $ 0  
Amount of Unrealized Gain/(Loss)       18  
Amount of Interest, Fees or Dividends Credited to Income       1,117  
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance       15,212  
Gross Additions       4,000  
Gross Reductions       1,395  
Ending balance   $ 17,817   17,817  
Investment, Identifier [Axis]: Chamberlin Holding LLC, Secured Debt February 26,2018          
Schedule of Investments [Line Items]          
Total Rate [6]         9.00%
Spread [6]         8.00%
Investment, Identifier [Axis]: Chamberlin Holding LLC, Secured Debt One | Other controlled investments          
Schedule of Investments [Line Items]          
Total Rate 8.63%   8.63%    
Spread 6.00%   6.00%    
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     0    
Amount of Interest, Fees or Dividends Credited to Income     6    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     0    
Gross Additions     0    
Gross Reductions     0    
Ending balance $ 0   $ 0    
Investment, Identifier [Axis]: Chamberlin Holding LLC, Secured Debt One February 26, 2018          
Schedule of Investments [Line Items]          
Spread [3],[4] 6.00%   6.00%    
Investment, Identifier [Axis]: Chamberlin Holding LLC, Secured Debt Two | Other controlled investments          
Schedule of Investments [Line Items]          
Total Rate 10.63%   10.63%    
Spread 8.00%   8.00%    
Amount of Realized Gain/(Loss)     $ 0    
Amount of Unrealized Gain/(Loss)     (51)    
Amount of Interest, Fees or Dividends Credited to Income     1,314    
Investments in and Advances to Affiliates, at Fair Value [Roll Forward]          
Beginning balance     17,817    
Gross Additions     51    
Gross Reductions     402