| CONSOLIDATED SCHEDULE OF INVESTMENTS (Parentheticals) - USD ($)
 | Jun. 30, 2023 | Sep. 30, 2022 | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 199.80% | [1],[2],[3],[4] | 205.90% | [5],[6],[7],[8] | 
| Line of credit facility, available | [5],[6],[7],[8],[9] |  |  | $ 4,000,000 |  | 
| Investments owned, fair value |  | $ 715,324,000 |  | $ 649,615,000 |  | 
| Percentage threshold of qualified assets representing total assets in order to acquire non-qualified assets |  | 70.00% |  | 70.00% |  | 
| Debt instrument, leverage maturity, terms |  | 2 years |  | 2 years |  | 
| Cumulative net unrealized appreciation |  |  |  | $ 52,300,000 |  | 
| Cumulative gross unrealized depreciation |  |  |  | 35,200,000 |  | 
| Cumulative gross unrealized appreciation for federal income tax purposes |  |  |  | 17,100,000 |  | 
| Based on a tax cost |  |  |  | 666,700,000 |  | 
| Cost |  | $ 735,182,000 |  | $ 656,053,000 |  | 
| London Interbank Offered Rate (LIBOR)_30 day |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, interest rate, paid in cash |  | 5.22% |  | 3.14% |  | 
| Secured Overnight Financing Rate (SOFR) |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, interest rate, paid in cash |  | 5.14% |  | 3.04% |  | 
| London Interbank Offered Rate (LIBOR)_90 day |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, interest rate, paid in cash |  |  |  | 3.75% |  | 
| Secured Overnight Financing Rate (SOFR) _90 day |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, interest rate, paid in cash |  | 5.27% |  |  |  | 
| LIBOR |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  |  |  | 6.50% |  | 
| Investment, basis spread, variable rate, floor |  |  |  | 1.00% |  | 
| Prime Rate |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, interest rate, paid in cash |  |  |  | 6.25% |  | 
| Funko Acquisition Holdings, LLC |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | $ 31,000,000 |  | $ 58,000 |  | 
| Percentage of acquired non-qualifying assets of total assets |  | 0.10% |  | 1.00% |  | 
| Collateral Pledged |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | $ 649,200,000 |  | $ 577,600,000 |  | 
| Aerospace and Defense |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 87,932,000 |  | 88,649,000 |  | 
| Beverage, Food, and Tobacco |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 74,641,000 |  | 64,283,000 |  | 
| Diversified/Conglomerate Manufacturing |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 160,904,000 |  | 114,105,000 |  | 
| Diversified/Conglomerate Service |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 164,261,000 |  | 148,907,000 |  | 
| Healthcare, Education, and Childcare |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 145,011,000 |  | 136,401,000 |  | 
| Machinery |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 6,676,000 |  | 9,562,000 |  | 
| Telecommunications |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 5,976,000 |  | 10,088,000 |  | 
| Automobile |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 22,191,000 |  | 20,144,000 |  | 
| Oil and Gas |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 26,887,000 |  | 25,373,000 |  | 
| Textiles and Leather |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 0 |  | 7,978,000 |  | 
| Secured first lien debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 533,237,000 |  | 463,858,000 |  | 
| Cost |  | 549,860,000 |  | 475,806,000 |  | 
| Secured second lien debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 120,036,000 |  | 115,928,000 |  | 
| Cost |  | 122,681,000 |  | 118,949,000 |  | 
| Unsecured debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 32,000 |  | 55,000 |  | 
| Cost |  | 198,000 |  | 293,000 |  | 
| Preferred Equity |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 27,991,000 |  | 27,046,000 |  | 
| Cost |  | 35,617,000 |  | 34,505,000 |  | 
| Common Equity/ Equivalents |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 34,028,000 |  | 42,728,000 |  | 
| Cost |  | $ 26,826,000 |  | $ 26,500,000 |  | 
| Non-Control/Non-Affiliate investments |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 179.60% | [1],[2],[3],[4],[10] | 182.20% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value |  | $ 642,847,000 | [10] | $ 574,811,000 | [11] | 
| Cost |  | $ 650,784,000 | [10] | $ 571,736,000 | [11] | 
| Non-Control/Non-Affiliate investments | Secured first lien debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 134.60% | [1],[2],[3],[4],[10] | 131.20% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value |  | $ 481,679,000 | [10] | $ 413,631,000 | [11] | 
| Cost |  | $ 494,074,000 | [10] | $ 420,857,000 | [11] | 
| Non-Control/Non-Affiliate investments | Secured first lien debt | Aerospace and Defense |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 20.00% | [1],[2],[3],[4],[10] | 23.40% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value |  | $ 71,575,000 | [10] | $ 73,898,000 | [11] | 
| Cost |  | $ 72,090,000 | [10] | $ 74,112,000 | [11] | 
| Non-Control/Non-Affiliate investments | Secured first lien debt | Beverage, Food, and Tobacco |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 19.30% | [1],[2],[3],[4],[10] | 18.70% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value |  | $ 69,183,000 | [10] | $ 58,971,000 | [11] | 
| Cost |  | $ 71,300,000 | [10] | $ 59,730,000 | [11] | 
| Non-Control/Non-Affiliate investments | Secured first lien debt | Buildings and Real Estate |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.60% | [1],[2],[3],[4],[10] | 0.50% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value |  | $ 2,012,000 | [10] | $ 1,654,000 | [11] | 
| Cost |  | $ 2,150,000 | [10] | $ 1,700,000 | [11] | 
| Non-Control/Non-Affiliate investments | Secured first lien debt | Diversified/Conglomerate Manufacturing |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 32.20% | [1],[2],[3],[4],[10] | 22.30% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value |  | $ 115,251,000 | [10] | $ 70,117,000 | [11] | 
| Cost |  | $ 117,983,000 | [10] | $ 70,815,000 | [11] | 
| Non-Control/Non-Affiliate investments | Secured first lien debt | Diversified/Conglomerate Service |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 29.60% | [1],[2],[3],[4],[10] | 31.10% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value |  | $ 105,816,000 | [10] | $ 97,884,000 | [11] | 
| Cost |  | $ 111,164,000 | [10] | $ 101,924,000 | [11] | 
| Non-Control/Non-Affiliate investments | Secured first lien debt | Healthcare, Education, and Childcare |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 29.70% | [1],[2],[3],[4],[10] | 31.30% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value |  | $ 106,344,000 | [10] | $ 98,881,000 | [11] | 
| Cost |  | $ 106,352,000 | [10] | $ 99,644,000 | [11] | 
| Non-Control/Non-Affiliate investments | Secured first lien debt | Machinery |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 1.50% | [1],[2],[3],[4],[10] | 1.70% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value |  | $ 5,522,000 | [10] | $ 5,350,000 | [11] | 
| Cost |  | $ 5,835,000 | [10] | $ 5,625,000 | [11] | 
| Non-Control/Non-Affiliate investments | Secured first lien debt | Printing and Publishing |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets | [5],[6],[7],[8],[11] |  |  | 0.00% |  | 
| Non-Control/Non-Affiliate investments | Secured first lien debt | Telecommunications |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 1.70% | [1],[2],[3],[4],[10] | 2.20% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value |  | $ 5,976,000 | [10] | $ 6,876,000 | [11] | 
| Cost |  | $ 7,200,000 | [10] | $ 7,200,000 | [11] | 
| Non-Control/Non-Affiliate investments | Secured second lien debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 31.50% | [1],[2],[3],[4],[10] | 34.30% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value |  | $ 112,611,000 | [10] | $ 108,263,000 | [11] | 
| Cost |  | $ 115,256,000 | [10] | $ 111,284,000 | [11] | 
| Non-Control/Non-Affiliate investments | Secured second lien debt | Beverage, Food, and Tobacco |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.70% | [1],[2],[3],[4],[10] | 1.00% | [5],[6],[7],[8],[11] | 
| Non-Control/Non-Affiliate investments | Secured second lien debt | Diversified/Conglomerate Manufacturing |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 10.10% | [1],[2],[3],[4],[10] | 10.80% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value |  | $ 36,188,000 | [10] | $ 34,051,000 | [11] | 
| Cost |  | $ 36,849,000 | [10] | $ 34,829,000 | [11] | 
| Non-Control/Non-Affiliate investments | Secured second lien debt | Diversified/Conglomerate Service |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 3.20% | [1],[2],[3],[4],[10] | 2.30% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value |  | $ 11,349,000 | [10] | $ 7,265,000 | [11] | 
| Cost |  | $ 11,526,000 | [10] | $ 7,512,000 | [11] | 
| Non-Control/Non-Affiliate investments | Secured second lien debt | Healthcare, Education, and Childcare |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 8.00% | [1],[2],[3],[4],[10] | 9.10% | [5],[6],[7],[8],[11] | 
| Non-Control/Non-Affiliate investments | Secured second lien debt | Machinery |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.20% | [1],[2],[3],[4],[10] | 0.20% | [5],[6],[7],[8],[11] | 
| Non-Control/Non-Affiliate investments | Secured second lien debt | Automobile |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 3.30% | [1],[2],[3],[4],[10] | 3.50% | [5],[6],[7],[8],[11] | 
| Non-Control/Non-Affiliate investments | Secured second lien debt | Oil and Gas |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 6.00% | [1],[2],[3],[4],[10] | 7.40% | [5],[6],[7],[8],[11] | 
| Non-Control/Non-Affiliate investments | Unsecured debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.00% | [1],[2],[3],[4],[10] | 0.00% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value | [10] | $ 32,000 |  |  |  | 
| Cost | [10] | $ 198,000 |  |  |  | 
| Non-Control/Non-Affiliate investments | Unsecured debt | Diversified/Conglomerate Service |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.00% | [1],[2],[3],[4],[10] | 0.00% | [5],[6],[7],[8],[11] | 
| Non-Control/Non-Affiliate investments | Preferred Equity |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 6.10% | [1],[2],[3],[4],[10] | 5.60% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value |  | $ 21,726,000 | [10] | $ 17,719,000 | [11] | 
| Cost |  | $ 23,061,000 | [10] | $ 21,949,000 | [11] | 
| Non-Control/Non-Affiliate investments | Preferred Equity | Beverage, Food, and Tobacco |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.00% | [1],[2],[3],[4],[10] | 0.00% | [5],[6],[7],[8],[11] | 
| Non-Control/Non-Affiliate investments | Preferred Equity | Buildings and Real Estate |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.10% | [1],[2],[3],[4],[10] | 0.20% | [5],[6],[7],[8],[11] | 
| Non-Control/Non-Affiliate investments | Preferred Equity | Diversified/Conglomerate Manufacturing |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.60% | [1],[2],[3],[4],[10] | 0.80% | [5],[6],[7],[8],[11] | 
| Non-Control/Non-Affiliate investments | Preferred Equity | Diversified/Conglomerate Service |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 2.70% | [1],[2],[3],[4],[10] | 2.60% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value |  | $ 9,654,000 | [10] | $ 8,151,000 | [11] | 
| Cost |  | $ 8,250,000 | [10] | $ 7,500,000 | [11] | 
| Non-Control/Non-Affiliate investments | Preferred Equity | Healthcare, Education, and Childcare |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 1.20% | [1],[2],[3],[4],[10] | 0.30% | [5],[6],[7],[8],[11] | 
| Non-Control/Non-Affiliate investments | Preferred Equity | Telecommunications |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.00% | [1],[2],[3],[4],[10] | 1.10% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value | [11] |  |  | $ 3,187,000 |  | 
| Cost | [11] |  |  | $ 2,813,000 |  | 
| Non-Control/Non-Affiliate investments | Preferred Equity | Automobile |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.00% | [1],[2],[3],[4],[10] | 0.00% | [5],[6],[7],[8],[11] | 
| Non-Control/Non-Affiliate investments | Preferred Equity | Oil and Gas |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 1.50% | [1],[2],[3],[4],[10] | 0.60% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value |  | $ 5,275,000 | [10] | $ 2,028,000 | [11] | 
| Cost |  | $ 6,838,000 | [10] | $ 6,982,000 | [11] | 
| Non-Control/Non-Affiliate investments | Common Equity/ Equivalents |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 7.40% | [1],[2],[3],[4],[10] | 11.10% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value |  | $ 26,799,000 | [10] | $ 35,143,000 | [11] | 
| Cost |  | $ 18,195,000 | [10] | $ 17,448,000 | [11] | 
| Non-Control/Non-Affiliate investments | Common Equity/ Equivalents | Aerospace and Defense |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 4.60% | [1],[2],[3],[4],[10] | 4.70% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value |  | $ 16,357,000 | [10] | $ 14,751,000 | [11] | 
| Cost |  | $ 5,283,000 | [10] | $ 5,283,000 | [11] | 
| Non-Control/Non-Affiliate investments | Common Equity/ Equivalents | Beverage, Food, and Tobacco |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.80% | [1],[2],[3],[4],[10] | 0.70% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value |  | $ 2,892,000 | [10] | $ 2,172,000 | [11] | 
| Cost |  | $ 1,750,000 | [10] | $ 1,750,000 | [11] | 
| Non-Control/Non-Affiliate investments | Common Equity/ Equivalents | Buildings and Real Estate |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.00% | [1],[2],[3],[4],[10] | 0.00% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value | [10] | $ 855,000 |  |  |  | 
| Cost | [10] | $ 5,000,000 |  |  |  | 
| Non-Control/Non-Affiliate investments | Common Equity/ Equivalents | Diversified/Conglomerate Manufacturing |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.20% | [1],[2],[3],[4],[10] | 0.60% | [5],[6],[7],[8],[11] | 
| Non-Control/Non-Affiliate investments | Common Equity/ Equivalents | Diversified/Conglomerate Service |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.10% | [1],[2],[3],[4],[10] | 0.10% | [5],[6],[7],[8],[11] | 
| Non-Control/Non-Affiliate investments | Common Equity/ Equivalents | Healthcare, Education, and Childcare |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 1.60% | [1],[2],[3],[4],[10] | 2.50% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value |  | $ 5,726,000 | [10] | $ 7,775,000 | [11] | 
| Cost |  | $ 2,786,000 | [10] | $ 2,009,000 | [11] | 
| Non-Control/Non-Affiliate investments | Common Equity/ Equivalents | Machinery |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.00% | [1],[2],[3],[4],[10] | 0.00% | [5],[6],[7],[8],[11] | 
| Non-Control/Non-Affiliate investments | Common Equity/ Equivalents | Telecommunications |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.00% | [1],[2],[3],[4],[10] | 0.00% | [5],[6],[7],[8],[11] | 
| Non-Control/Non-Affiliate investments | Common Equity/ Equivalents | Automobile |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.10% | [1],[2],[3],[4],[10] | 0.00% | [5],[6],[7],[8],[11] | 
| Non-Control/Non-Affiliate investments | Common Equity/ Equivalents | Oil and Gas |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.00% | [1],[2],[3],[4],[10] | 0.00% | [5],[6],[7],[8],[11] | 
| Investments owned, fair value |  | $ 119,000 | [10] | $ 50,000 | [11] | 
| Cost |  | $ 499,000 | [10] | $ 499,000 | [11] | 
| Non-Control/Non-Affiliate investments | Common Equity/ Equivalents | Personal and Non-Durable Consumer Products (Manufacturing Only) |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.00% | [1],[2],[3],[4],[10] | 0.00% | [5],[6],[7],[8],[11] | 
| Non-Control/Non-Affiliate investments | Common Equity/ Equivalents | Textiles and Leather |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets | [5],[6],[7],[8],[11] |  |  | 2.50% |  | 
| Affiliate investments |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 11.70% | [1],[2],[3],[4],[12] | 12.40% | [5],[6],[7],[8],[13] | 
| Investments owned, fair value |  | $ 42,023,000 |  | $ 39,091,000 |  | 
| Cost |  | $ 50,327,000 |  | $ 49,412,000 |  | 
| Affiliate investments | Secured first lien debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 9.90% | [1],[2],[3],[4],[12] | 11.00% | [5],[6],[7],[8],[13] | 
| Investments owned, fair value |  | $ 35,493,000 | [12] | $ 34,804,000 | [13] | 
| Cost |  | $ 39,721,000 | [12] | $ 39,306,000 | [13] | 
| Affiliate investments | Secured first lien debt | Diversified/Conglomerate Manufacturing |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.80% | [1],[2],[3],[4],[12] | 0.80% | [5],[6],[7],[8],[13] | 
| Affiliate investments | Secured first lien debt | Diversified/Conglomerate Service |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 9.10% | [1],[2],[3],[4],[12] | 10.20% | [5],[6],[7],[8],[13] | 
| Investments owned, fair value |  | $ 32,741,000 | [12] | $ 32,254,000 | [13] | 
| Cost |  | $ 33,581,000 | [12] | $ 33,166,000 | [13] | 
| Affiliate investments | Preferred Equity |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 1.40% | [1],[2],[3],[4],[12] | 1.20% | [5],[6],[7],[8],[13] | 
| Investments owned, fair value |  | $ 5,124,000 | [12] | $ 3,640,000 | [13] | 
| Cost |  | $ 9,806,000 | [12] | $ 9,806,000 | [13] | 
| Affiliate investments | Preferred Equity | Diversified/Conglomerate Manufacturing |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.00% | [1],[2],[3],[4],[12] | 0.00% | [5],[6],[7],[8],[13] | 
| Affiliate investments | Preferred Equity | Diversified/Conglomerate Service |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 1.20% | [1],[2],[3],[4],[12] | 0.90% | [5],[6],[7],[8],[13] | 
| Affiliate investments | Preferred Equity | Personal and Non-Durable Consumer Products (Manufacturing Only) |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.20% | [1],[2],[3],[4],[12] | 0.30% | [5],[6],[7],[8],[13] | 
| Affiliate investments | Common Equity/ Equivalents |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.40% | [1],[2],[3],[4],[12] | 0.20% | [5],[6],[7],[8],[13] | 
| Investments owned, fair value |  | $ 42,023,000 | [12] | $ 39,091,000 | [13] | 
| Cost |  | $ 50,327,000 | [12] | $ 49,412,000 | [13] | 
| Affiliate investments | Common Equity/ Equivalents | Personal and Non-Durable Consumer Products (Manufacturing Only) |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.40% | [1],[2],[3],[4],[12] | 0.20% | [5],[6],[7],[8],[13] | 
| Investments owned, fair value |  | $ 1,406,000 | [12] | $ 647,000 | [13] | 
| Cost |  | $ 800,000 | [12] | $ 300,000 | [13] | 
| Control investments |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 8.50% | [1],[2],[3],[4],[14] | 11.30% | [5],[6],[7],[8],[15] | 
| Investments owned, fair value |  | $ 30,454,000 | [14] | $ 35,713,000 | [15] | 
| Cost |  | $ 34,071,000 | [14] | $ 34,905,000 | [15] | 
| Control investments | Secured first lien debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 4.50% | [1],[2],[3],[4],[14] | 4.90% | [5],[6],[7],[8],[15] | 
| Control investments | Secured first lien debt | Diversified/Conglomerate Manufacturing |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 1.10% | [1],[2],[3],[4],[14] | 1.00% | [5],[6],[7],[8],[15] | 
| Control investments | Secured first lien debt | Printing and Publishing |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.20% | [1],[2],[3],[4],[14] | 0.30% | [5],[6],[7],[8],[15] | 
| Investments owned, fair value |  | $ 16,065,000 | [14] | $ 15,423,000 | [15] | 
| Cost |  | $ 16,065,000 | [14] | $ 15,643,000 | [15] | 
| Control investments | Secured first lien debt | Personal and Non-Durable Consumer Products (Manufacturing Only) |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 3.20% | [1],[2],[3],[4],[14] | 3.60% | [5],[6],[7],[8],[15] | 
| Investments owned, fair value |  | $ 11,318,000 | [14] | $ 11,393,000 | [15] | 
| Cost |  | $ 11,318,000 | [14] | $ 11,393,000 | [15] | 
| Control investments | Secured second lien debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 2.10% | [1],[2],[3],[4],[14] | 2.40% | [5],[6],[7],[8],[15] | 
| Control investments | Secured second lien debt | Automobile |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 2.10% | [1],[2],[3],[4],[14] | 2.40% | [5],[6],[7],[8],[15] | 
| Control investments | Unsecured debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets | [5],[6],[7],[8],[15] |  |  | 0.00% |  | 
| Control investments | Unsecured debt | Diversified/Conglomerate Manufacturing |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets | [5],[6],[7],[8],[15] |  |  | 0.00% |  | 
| Control investments | Preferred Equity |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.30% | [1],[2],[3],[4],[14] | 1.80% | [5],[6],[7],[8],[15] | 
| Control investments | Preferred Equity | Personal and Non-Durable Consumer Products (Manufacturing Only) |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.30% | [1],[2],[3],[4],[14] | 1.80% | [5],[6],[7],[8],[15] | 
| Control investments | Common Equity/ Equivalents |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 1.60% | [1],[2],[3],[4],[14] | 2.20% | [5],[6],[7],[8],[15] | 
| Investments owned, fair value |  | $ 5,823,000 | [14] | $ 6,938,000 | [15] | 
| Cost |  | $ 7,831,000 | [14] | $ 8,752,000 | [15] | 
| Control investments | Common Equity/ Equivalents | Diversified/Conglomerate Manufacturing |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.00% | [1],[2],[3],[4],[14] | 0.00% | [5],[6],[7],[8],[15] | 
| Investments owned, fair value | [15] |  |  | $ 0 |  | 
| Cost | [15] |  |  | $ 7,671,000 |  | 
| Control investments | Common Equity/ Equivalents | Machinery |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.10% | [1],[2],[3],[4],[14] | 1.10% | [5],[6],[7],[8],[15] | 
| Control investments | Common Equity/ Equivalents | Printing and Publishing |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.80% | [1],[2],[3],[4],[14] | 0.70% | [5],[6],[7],[8],[15] | 
| Control investments | Common Equity/ Equivalents | Automobile |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment owned, percent of net assets |  | 0.70% | [1],[2],[3],[4],[14] | 0.40% | [5],[6],[7],[8],[15] | 
| Investment, Identifier [Axis]: Leeds Novamark Capital I, L.P. – Limited Partnership Interest ($843 uncalled capital commitment |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Line of credit facility, available |  | $ 843,000 | [1],[2],[3],[4],[16],[17],[18] | $ 843,000 | [5],[6],[7],[8],[19],[20],[21] | 
| Investments owned, fair value |  | 193,000 | [16],[17],[18],[22] | 6,397,000 | [19],[20],[21] | 
| Cost |  | 0 | [16],[17],[18],[22] | 1,223,000 | [19],[20],[21] | 
| Investment, Identifier [Axis]: Antenna Research Associates, Inc. – Common Equity Units |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 15,814,000 | [17],[22] | 13,734,000 | [20],[23] | 
| Cost |  | $ 4,283,000 | [17],[22] | $ 4,283,000 | [20],[23] | 
| Shares |  | 4,283 | [17],[22],[24],[25] | 4,283 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: Engineering Manufacturing Technologies, LLC – Common Stock |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | $ 0 | [17],[22] | $ 1,773,000 | [20],[23] | 
| Cost |  | $ 3,000,000 | [17],[22] | $ 3,000,000 | [20],[23] | 
| Shares |  | 6,000 | [17],[22],[24],[25] | 6,000 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: NeoGraf Solutions LLC |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value | [17],[22] | $ 855,000 |  |  |  | 
| Cost | [17],[22] | $ 2,000,000 |  |  |  | 
| Shares | [17],[22],[24],[25] | 2,000,000 |  |  |  | 
| Investment, Identifier [Axis]: OCI, LLC – Common Units |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value | [17],[22] | $ 0 |  |  |  | 
| Cost | [17],[22] | $ 0 |  |  |  | 
| Shares | [17],[22],[24],[25] | 306 |  |  |  | 
| Investment, Identifier [Axis]: Ohio Armor Holdings, LLC – Common Equity |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | $ 543,000 | [17],[22] | $ 1,017,000 | [20],[23] | 
| Cost |  | $ 1,000,000 | [17],[22] | $ 1,000,000 | [20],[23] | 
| Shares |  | 100 | [17],[22],[24],[25] | 100 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: WorkforceQA, LLC – Common Stock |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | $ 391,000 | [17],[22] | $ 456,000 | [20],[23] | 
| Cost |  | $ 532,000 | [17],[22] | $ 500,000 | [20],[23] | 
| Shares |  | 532 | [17],[22],[24],[25] | 500 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: 8th Avenue Food & Provisions, Inc. – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 7.90% | [1],[2],[3],[4],[28] | 7.80% | [5],[6],[7],[8],[29] | 
| Investment, interest rate, paid in cash |  | 13.00% | [1],[2],[3],[4],[28] | 10.90% | [5],[6],[7],[8],[29] | 
| Investments owned, fair value |  | $ 2,431,000 | [28] | $ 3,020,000 | [29] | 
| Principal amount |  | 3,683,000 | [24],[25],[28] | 3,682,000 | [26],[27],[29] | 
| Cost |  | $ 3,683,000 | [28] | $ 3,698,000 | [29] | 
| Investment, Identifier [Axis]: ALS Education, LLC – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 7.00% | [1],[2],[3],[4],[30] | 7.00% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 12.10% | [1],[2],[3],[4],[30] | 10.10% | [5],[6],[7],[8],[9] | 
| Line of credit facility, available |  | $ 3,000,000 | [1],[2],[3],[4],[30] | $ 3,000,000 | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | 0 | [30] | 0 | [9] | 
| Principal amount |  | 0 | [24],[25],[30] | 0 | [9],[26],[27] | 
| Cost |  | $ 0 | [30] | $ 0 | [9] | 
| Investment, Identifier [Axis]: ALS Education, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 7.00% | [1],[2],[3],[4],[30] | 7.00% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 12.10% | [1],[2],[3],[4],[30] | 10.10% | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | $ 18,982,000 | [30] | $ 19,468,000 | [9] | 
| Principal amount |  | 19,030,000 | [24],[25],[30] | 19,690,000 | [9],[26],[27] | 
| Cost |  | $ 19,030,000 | [30] | $ 19,690,000 | [9] | 
| Investment, Identifier [Axis]: Antenna Research Associates, Inc. – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 10.00% | [1],[2],[3],[4],[22] | 10.00% | [5],[6],[7],[8],[23] | 
| Investment, interest rate, paid in cash |  | 15.10% | [1],[2],[3],[4],[22] | 13.00% | [5],[6],[7],[8],[23] | 
| Investment, interest rate, paid in kind |  | 4.00% | [1],[2],[3],[4],[22] | 4.00% | [5],[6],[7],[8],[23] | 
| Investments owned, fair value | [22] | $ 22,041,000 |  | $ 21,973,000 |  | 
| Principal amount | [22] | 22,041,000 | [24],[25] | 21,973,000 | [26],[27] | 
| Cost | [22] | 22,041,000 |  | 21,973,000 |  | 
| Investment, Identifier [Axis]: Arc Drilling Holdings LLC – Common Stock |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 106,000 | [17],[22] | 0 | [20],[23] | 
| Cost |  | $ 1,500,000 | [17],[22] | $ 1,500,000 | [20],[23] | 
| Shares |  | 15,000 | [17],[22],[24],[25] | 15,000 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: Arc Drilling Holdings LLC – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 11.50% | [1],[2],[3],[4],[30] | 8.00% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 10.50% | [1],[2],[3],[4],[30] | 11.10% | [5],[6],[7],[8],[9] | 
| Line of credit facility, available |  | $ 1,000,000 | [1],[2],[3],[4],[30] | $ 1,000,000 | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | 0 | [30] | 0 | [9] | 
| Principal amount |  | 0 | [24],[25],[30] | 0 | [9],[26],[27] | 
| Cost |  | $ 0 | [30] | $ 0 | [9] | 
| Investment, Identifier [Axis]: Arc Drilling Holdings LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 11.50% | [1],[2],[3],[4],[30] | 9.50% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 10.50% | [1],[2],[3],[4],[30] | 12.60% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in kind |  | 6.10% | [1],[2],[3],[4],[30] | 3.00% | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | $ 5,522,000 | [30] | $ 5,350,000 | [9] | 
| Principal amount |  | 5,835,000 | [24],[25],[30] | 5,625,000 | [9],[26],[27] | 
| Cost |  | $ 5,835,000 | [30] | $ 5,625,000 | [9] | 
| Investment, Identifier [Axis]: Axios Industrial Group, LLC – Delayed Draw Term Loan |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30] | 9.10% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30] | 14.20% |  |  |  | 
| Line of credit facility, available | [1],[2],[3],[4],[30] | $ 5,000,000 |  |  |  | 
| Investments owned, fair value | [30] | 2,948,000 |  |  |  | 
| Principal amount | [24],[25],[30] | 3,000,000 |  |  |  | 
| Cost | [30] | $ 3,000,000 |  |  |  | 
| Investment, Identifier [Axis]: Axios Industrial Group, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [5],[6],[7],[8],[9],[31] |  |  | 9.50% |  | 
| Investment, interest rate, paid in cash | [5],[6],[7],[8],[9],[31] |  |  | 12.60% |  | 
| Investments owned, fair value | [9],[31] |  |  | $ 8,741,000 |  | 
| Principal amount | [9],[26],[27],[31] |  |  | 9,000,000 |  | 
| Cost | [9],[31] |  |  | $ 9,000,000 |  | 
| Investment, Identifier [Axis]: Axios Industrial Group, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30] | 9.10% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30] | 14.20% |  |  |  | 
| Investments owned, fair value | [30] | $ 8,843,000 |  |  |  | 
| Principal amount | [24],[25],[30] | 9,000,000 |  |  |  | 
| Cost | [30] | 8,967,000 |  |  |  | 
| Investment, Identifier [Axis]: Axios Industrial Group, LLC– Delayed Draw Term Loan |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [5],[6],[7],[8],[9],[31] |  |  | 9.50% |  | 
| Investment, interest rate, paid in cash | [5],[6],[7],[8],[9],[31] |  |  | 12.60% |  | 
| Line of credit facility, available | [5],[6],[7],[8],[9],[31] |  |  | $ 5,000,000 |  | 
| Investments owned, fair value | [9],[31] |  |  | 2,914,000 |  | 
| Principal amount | [9],[26],[27],[31] |  |  | 3,000,000 |  | 
| Cost | [9],[31] |  |  | 3,000,000 |  | 
| Investment, Identifier [Axis]: B+T Group Acquisition, Inc.(S) – Common Stock Warrant |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 0 | [17],[22],[32] | 25,000 | [20],[23],[33] | 
| Cost |  | $ 0 | [17],[22],[32] | $ 0 | [20],[23],[33] | 
| Investment, Identifier [Axis]: B+T Group Acquisition, Inc.(S) – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 11.00% | [1],[2],[3],[4],[30],[32] | 11.00% | [5],[6],[7],[8],[9],[33] | 
| Investment, interest rate, paid in cash |  | 16.10% | [1],[2],[3],[4],[30],[32] | 14.10% | [5],[6],[7],[8],[9],[33] | 
| Line of credit facility, available |  | $ 0 | [1],[2],[3],[4],[30],[32] | $ 0 | [5],[6],[7],[8],[9],[33] | 
| Investments owned, fair value |  | 996,000 | [30],[32] | 1,146,000 | [9],[33] | 
| Principal amount |  | 1,200,000 | [24],[25],[30],[32] | 1,200,000 | [9],[26],[27],[33] | 
| Cost |  | 1,200,000 | [30],[32] | 1,200,000 | [9],[33] | 
| Investment, Identifier [Axis]: B+T Group Acquisition, Inc.(S) – Preferred Stock |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 0 | [17],[22],[32] | 2,718,000 | [20],[23],[33] | 
| Cost |  | $ 2,024,000 | [17],[22],[32] | $ 2,024,000 | [20],[23],[33] | 
| Shares |  | 6,130 | [17],[22],[24],[25],[32] | 6,130 | [20],[23],[26],[27],[33] | 
| Investment, Identifier [Axis]: B+T Group Acquisition, Inc.(S) – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 11.00% | [1],[2],[3],[4],[30],[32] | 11.00% | [5],[6],[7],[8],[9],[33] | 
| Investment, interest rate, paid in cash |  | 16.10% | [1],[2],[3],[4],[30],[32] | 14.10% | [5],[6],[7],[8],[9],[33] | 
| Investments owned, fair value |  | $ 4,980,000 | [30],[32] | $ 5,730,000 | [9],[33] | 
| Principal amount |  | 6,000,000 | [24],[25],[30],[32] | 6,000,000 | [9],[26],[27],[33] | 
| Cost |  | $ 6,000,000 | [30],[32] | $ 6,000,000 | [9],[33] | 
| Investment, Identifier [Axis]: CHA Holdings, Inc. – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 9.00% | [1],[2],[3],[4],[28],[34] | 8.80% | [5],[6],[7],[8],[29],[35] | 
| Investment, interest rate, paid in cash |  | 14.30% | [1],[2],[3],[4],[28],[34] | 12.50% | [5],[6],[7],[8],[29],[35] | 
| Investments owned, fair value |  | $ 2,760,000 | [28],[34] | $ 2,700,000 | [29],[35] | 
| Principal amount |  | 3,000,000 | [24],[25],[28],[34] | 3,000,000 | [26],[27],[29],[35] | 
| Cost |  | $ 2,973,000 | [28],[34] | $ 2,967,000 | [29],[35] | 
| Investment, Identifier [Axis]: CPM Holdings, Inc. – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 8.30% | [1],[2],[3],[4],[28] | 8.30% | [5],[6],[7],[8],[29] | 
| Investment, interest rate, paid in cash |  | 13.50% | [1],[2],[3],[4],[28] | 11.40% | [5],[6],[7],[8],[29] | 
| Investments owned, fair value |  | $ 792,000 | [28] | $ 758,000 | [29] | 
| Principal amount |  | 798,000 | [24],[25],[28] | 798,000 | [26],[27],[29] | 
| Cost |  | $ 798,000 | [28] | $ 798,000 | [29] | 
| Investment, Identifier [Axis]: Café Zupas – Delayed Draw Term Loan |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 6.80% | [1],[2],[3],[4],[30] | 7.40% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 11.90% | [1],[2],[3],[4],[30] | 10.50% | [5],[6],[7],[8],[9] | 
| Line of credit facility, available |  | $ 6,070,000 | [1],[2],[3],[4],[30] | $ 0 | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | 3,891,000 | [30] | 1,958,000 | [9] | 
| Principal amount |  | 3,970,000 | [24],[25],[30] | 1,970,000 | [9],[26],[27] | 
| Cost |  | $ 3,970,000 | [30] | $ 1,970,000 | [9] | 
| Investment, Identifier [Axis]: Café Zupas – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30] | 6.80% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30] | 11.90% |  |  |  | 
| Line of credit facility, available | [1],[2],[3],[4],[30] | $ 1,500,000 |  |  |  | 
| Investments owned, fair value | [30] | 0 |  |  |  | 
| Principal amount | [24],[25],[30] | 0 |  |  |  | 
| Cost | [30] | $ 0 |  |  |  | 
| Investment, Identifier [Axis]: Café Zupas – Line of Credit, |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [5],[6],[7],[8],[9] |  |  | 7.40% |  | 
| Investment, interest rate, paid in cash | [5],[6],[7],[8],[9] |  |  | 10.50% |  | 
| Investments owned, fair value | [9] |  |  | $ 0 |  | 
| Principal amount | [9],[26],[27] |  |  | 0 |  | 
| Cost | [9] |  |  | $ 0 |  | 
| Investment, Identifier [Axis]: Café Zupas – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 6.80% | [1],[2],[3],[4],[30] | 7.40% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 11.90% | [1],[2],[3],[4],[30] | 10.50% | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | $ 22,991,000 | [30] | $ 23,313,000 | [9] | 
| Principal amount |  | 23,460,000 | [24],[25],[30] | 23,460,000 | [9],[26],[27] | 
| Cost |  | 23,460,000 | [30] | 23,460,000 | [9] | 
| Investment, Identifier [Axis]: Canopy Safety Brands, LLC – Common Stock |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 1,406,000 | [17],[22] | 647,000 | [20],[23] | 
| Cost |  | $ 800,000 | [17],[22] | $ 300,000 | [20],[23] | 
| Shares |  | 1,170,370 | [17],[22],[24],[25] | 800,000 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: Canopy Safety Brands, LLC – Preferred Stock |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | $ 846,000 | [17],[22] | $ 798,000 | [20],[23] | 
| Cost |  | $ 500,000 | [17],[22] | $ 500,000 | [20],[23] | 
| Shares |  | 500,000 | [17],[22],[24],[25] | 500,000 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: Chinese Yellow Pages Company – Line of Credit, |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [5],[6],[7],[8],[23],[36],[37] |  |  | 4.00% |  | 
| Investment, interest rate, paid in cash | [5],[6],[7],[8],[23],[36],[37] |  |  | 10.30% |  | 
| Line of credit facility, available | [5],[6],[7],[8],[23],[36],[37] |  |  | $ 0 |  | 
| Investments owned, fair value | [23],[36],[37] |  |  | 0 |  | 
| Principal amount | [23],[26],[27],[36],[37] |  |  | 107,000 |  | 
| Cost | [23],[36],[37] |  |  | 107,000 |  | 
| Investment, Identifier [Axis]: Circuitronics EMS Holdings LLC – Common Units |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value | [20],[23] |  |  | 0 |  | 
| Cost | [20],[23] |  |  | $ 921,000 |  | 
| Shares | [20],[23],[26],[27] |  |  | 921,000 |  | 
| Investment, Identifier [Axis]: DKI Ventures, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 8.00% | [1],[2],[3],[4],[30] | 8.00% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 13.10% | [1],[2],[3],[4],[30] | 11.00% | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | $ 3,549,000 | [30] | $ 4,554,000 | [9] | 
| Principal amount |  | 5,915,000 | [24],[25],[30] | 5,915,000 | [9],[26],[27] | 
| Cost |  | 5,915,000 | [30] | 5,915,000 | [9] | 
| Investment, Identifier [Axis]: Defiance Integrated Technologies, Inc. – Common Stock |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 2,639,000 | [17],[22] | 1,147,000 | [20],[23] | 
| Cost |  | $ 580,000 | [17],[22] | $ 580,000 | [20],[23] | 
| Shares |  | 33,321 | [17],[22],[24],[25] | 33,321 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: Defiance Integrated Technologies, Inc. – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 9.60% | [1],[2],[3],[4],[22] | 9.50% | [5],[6],[7],[8],[23] | 
| Investment, interest rate, paid in cash |  | 14.70% | [1],[2],[3],[4],[22] | 12.60% | [5],[6],[7],[8],[23] | 
| Investments owned, fair value |  | $ 7,425,000 | [22] | $ 7,665,000 | [23] | 
| Principal amount |  | 7,425,000 | [22],[24],[25] | 7,665,000 | [23],[26],[27] | 
| Cost |  | $ 7,425,000 | [22] | $ 7,665,000 | [23] | 
| Investment, Identifier [Axis]: ENET Holdings, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [5],[6],[7],[8],[9] |  |  | 7.30% |  | 
| Investment, interest rate, paid in cash | [5],[6],[7],[8],[9] |  |  | 10.40% |  | 
| Investments owned, fair value | [9] |  |  | $ 23,142,000 |  | 
| Principal amount | [9],[26],[27] |  |  | 24,360,000 |  | 
| Cost | [9] |  |  | $ 24,360,000 |  | 
| Investment, Identifier [Axis]: ENET Holdings, LLC – Term Debt 2 |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30] | 7.30% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30] | 12.40% |  |  |  | 
| Investments owned, fair value | [30] | $ 21,453,000 |  |  |  | 
| Principal amount | [24],[25],[30] | 22,289,000 |  |  |  | 
| Cost | [30] | $ 22,289,000 |  |  |  | 
| Investment, Identifier [Axis]: Edge Adhesives Holdings, Inc. (S) – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 5.50% | [1],[2],[3],[4],[22],[32],[38] | 5.50% | [5],[6],[7],[8],[23],[33] | 
| Investment, interest rate, paid in cash |  | 10.60% | [1],[2],[3],[4],[22],[32],[38] | 8.60% | [5],[6],[7],[8],[23],[33] | 
| Investments owned, fair value |  | $ 2,752,000 | [30],[32],[38] | $ 2,550,000 | [23],[33] | 
| Principal amount |  | 6,140,000 | [24],[25],[30],[32],[38] | 6,140,000 | [23],[26],[27],[33] | 
| Cost |  | 6,140,000 | [30],[32],[38] | 6,140,000 | [23],[33] | 
| Investment, Identifier [Axis]: Edge Adhesives Holdings, Inc.(S) – Preferred Stock |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 0 | [17],[22],[32] | 0 | [20],[23],[33] | 
| Cost |  | $ 5,466,000 | [17],[22],[32] | $ 5,466,000 | [20],[23],[33] | 
| Shares |  | 5,466 | [17],[22],[24],[25],[32] | 5,466 | [20],[23],[26],[27],[33] | 
| Investment, Identifier [Axis]: Eegee’s LLC – Delayed Draw Term Loan |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 7.80% | [1],[2],[3],[4],[30] | 8.30% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 12.90% | [1],[2],[3],[4],[30] | 11.40% | [5],[6],[7],[8],[9] | 
| Line of credit facility, available |  | $ 4,500,000 | [1],[2],[3],[4],[30] | $ 4,500,000 | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | 2,873,000 | [30] | 2,910,000 | [9] | 
| Principal amount |  | 3,000,000 | [24],[25],[30] | 3,000,000 | [9],[26],[27] | 
| Cost |  | $ 3,000,000 | [30] | $ 3,000,000 | [9] | 
| Investment, Identifier [Axis]: Eegee’s LLC – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 7.80% | [1],[2],[3],[4],[30] | 8.30% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 12.90% | [1],[2],[3],[4],[30] | 11.40% | [5],[6],[7],[8],[9] | 
| Line of credit facility, available |  | $ 1,000,000 | [1],[2],[3],[4],[30] | $ 1,000,000 | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | 0 | [30] | 0 | [9] | 
| Principal amount |  | 0 | [24],[25],[30] | 0 | [9],[26],[27] | 
| Cost |  | $ 0 | [30] | $ 0 | [9] | 
| Investment, Identifier [Axis]: Eegee’s LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30] | 7.80% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30] | 12.90% |  |  |  | 
| Investments owned, fair value | [30] | $ 16,278,000 |  |  |  | 
| Principal amount | [24],[25],[30] | 17,000,000 |  |  |  | 
| Cost | [30] | $ 17,000,000 |  |  |  | 
| Investment, Identifier [Axis]: Eegee’s LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [5],[6],[7],[8],[9] |  |  | 8.30% |  | 
| Investment, interest rate, paid in cash | [5],[6],[7],[8],[9] |  |  | 11.40% |  | 
| Investments owned, fair value | [9] |  |  | $ 16,490,000 |  | 
| Principal amount | [9],[26],[27] |  |  | 17,000,000 |  | 
| Cost | [9] |  |  | $ 17,000,000 |  | 
| Investment, Identifier [Axis]: Encore Dredging Holdings, LLC – Delayed Draw Term Loan |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 7.00% | [1],[2],[3],[4],[30] | 7.00% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 12.10% | [1],[2],[3],[4],[30] | 10.10% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in kind |  | 1.50% | [1],[2],[3],[4],[30] | 1.50% | [5],[6],[7],[8],[9] | 
| Line of credit facility, available |  | $ 0 | [1],[2],[3],[4],[30] | $ 0 | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | 4,954,000 | [30] | 4,885,000 | [9] | 
| Principal amount |  | 5,081,000 | [24],[25],[30] | 5,023,000 | [9],[26],[27] | 
| Cost |  | $ 5,081,000 | [30] | $ 5,023,000 | [9] | 
| Investment, Identifier [Axis]: Encore Dredging Holdings, LLC – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 8.30% | [1],[2],[3],[4],[30] | 8.30% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 13.40% | [1],[2],[3],[4],[30] | 11.40% | [5],[6],[7],[8],[9] | 
| Line of credit facility, available |  | $ 3,000,000 | [1],[2],[3],[4],[30] | $ 3,000,000 | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | 0 | [30] | 0 | [9] | 
| Principal amount |  | 0 | [24],[25],[30] | 0 | [9],[26],[27] | 
| Cost |  | 0 | [30] | 0 | [9] | 
| Investment, Identifier [Axis]: Encore Dredging Holdings, LLC – Preferred Stock |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 4,278,000 | [17],[22] | 2,842,000 | [20],[23],[33] | 
| Cost |  | $ 3,840,000 | [17],[22] | $ 3,840,000 | [20],[23],[33] | 
| Shares |  | 3,840,000 | [17],[22],[24],[25] | 3,840,000 | [20],[23],[26],[27],[33] | 
| Investment, Identifier [Axis]: Encore Dredging Holdings, LLC – Term Debt 1 |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 7.00% | [1],[2],[3],[4],[30] | 7.00% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 12.10% | [1],[2],[3],[4],[30] | 10.10% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in kind |  | 1.50% | [1],[2],[3],[4],[30] | 1.50% | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | $ 23,284,000 | [30] | $ 22,962,000 | [9] | 
| Principal amount |  | 23,881,000 | [24],[25],[30] | 23,611,000 | [9],[26],[27] | 
| Cost |  | $ 23,881,000 | [30] | $ 23,611,000 | [9] | 
| Investment, Identifier [Axis]: Encore Dredging Holdings, LLC – Term Debt 2 |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 7.00% | [1],[2],[3],[4],[30] | 7.00% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 12.10% | [1],[2],[3],[4],[30] | 10.10% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in kind |  | 2.50% | [1],[2],[3],[4],[30] | 2.50% | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | $ 4,503,000 | [30] | $ 4,407,000 | [9] | 
| Principal amount |  | 4,619,000 | [24],[25],[30] | 4,532,000 | [9],[26],[27] | 
| Cost |  | $ 4,619,000 | [30] | $ 4,532,000 | [9] | 
| Investment, Identifier [Axis]: Engineering Manufacturing Technologies, LLC – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 8.30% | [1],[2],[3],[4],[30] | 8.30% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 13.40% | [1],[2],[3],[4],[30] | 11.40% | [5],[6],[7],[8],[9] | 
| Line of credit facility, available |  | $ 3,000,000 | [1],[2],[3],[4],[30] | $ 3,000,000 | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | 0 | [30] | 0 | [9] | 
| Principal amount |  | 0 | [24],[25],[30] | 0 | [9],[26],[27] | 
| Cost |  | $ 0 | [30] | $ 0 | [9] | 
| Investment, Identifier [Axis]: Engineering Manufacturing Technologies, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [5],[6],[7],[8],[9] |  |  | 8.30% |  | 
| Investment, interest rate, paid in cash | [5],[6],[7],[8],[9] |  |  | 11.40% |  | 
| Investments owned, fair value | [9] |  |  | $ 22,134,000 |  | 
| Principal amount | [9],[26],[27] |  |  | 22,500,000 |  | 
| Cost | [9] |  |  | 22,500,000 |  | 
| Investment, Identifier [Axis]: Engineering Manufacturing Technologies, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30] | 8.30% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30] | 13.40% |  |  |  | 
| Investments owned, fair value | [30] | $ 20,317,000 |  |  |  | 
| Principal amount | [24],[25],[30] | 21,500,000 |  |  |  | 
| Cost | [30] | 21,500,000 |  |  |  | 
| Investment, Identifier [Axis]: FES Resources Holdings LLC – Common Equity Units |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 0 | [17],[22] | 0 | [20],[23] | 
| Cost |  | $ 0 | [17],[22] | $ 0 | [20],[23] | 
| Shares |  | 6,233 | [17],[22],[24],[25] | 6,233 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: FES Resources Holdings LLC – Preferred Equity Units |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | $ 3,619,000 | [17],[22] | $ 0 | [20],[23] | 
| Cost |  | $ 6,350,000 | [17],[22] | $ 6,350,000 | [20],[23] | 
| Shares |  | 6,350 | [17],[22],[24],[25] | 6,350 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: Fix-It Group, LLC – Delayed Draw Term Loan |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 8.10% | [1],[2],[3],[4],[30] | 7.00% | [5],[6],[7],[8],[9],[35] | 
| Investment, interest rate, paid in cash |  | 13.20% | [1],[2],[3],[4],[30] | 10.10% | [5],[6],[7],[8],[9],[35] | 
| Line of credit facility, available |  | $ 0 | [1],[2],[3],[4],[30] | $ 10,000,000 | [5],[6],[7],[8],[9],[35] | 
| Investments owned, fair value |  | 6,911,000 | [30] | 0 | [9],[35] | 
| Principal amount |  | 6,911,000 | [24],[25],[30] | 0 | [9],[26],[27],[35] | 
| Cost |  | $ 6,911,000 | [30] | $ 0 | [9],[35] | 
| Investment, Identifier [Axis]: Fix-It Group, LLC – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 8.10% | [1],[2],[3],[4],[30] | 7.00% | [5],[6],[7],[8],[9],[35] | 
| Investment, interest rate, paid in cash |  | 13.20% | [1],[2],[3],[4],[30] | 10.10% | [5],[6],[7],[8],[9],[35] | 
| Line of credit facility, available |  | $ 2,000,000 | [1],[2],[3],[4],[30] | $ 3,000,000 | [5],[6],[7],[8],[9],[35] | 
| Investments owned, fair value |  | 1,000,000 | [30] | 0 | [9],[35] | 
| Principal amount |  | 1,000,000 | [24],[25],[30] | 0 | [9],[26],[27],[35] | 
| Cost |  | $ 1,000,000 | [30] | $ 0 | [9],[35] | 
| Investment, Identifier [Axis]: Fix-It Group, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 8.10% | [1],[2],[3],[4],[30] | 7.00% | [5],[6],[7],[8],[9],[35] | 
| Investment, interest rate, paid in cash |  | 13.20% | [1],[2],[3],[4],[30] | 10.10% | [5],[6],[7],[8],[9],[35] | 
| Investments owned, fair value |  | $ 12,200,000 | [30] | $ 9,950,000 | [9],[35] | 
| Principal amount |  | 12,200,000 | [24],[25],[30] | 10,000,000 | [9],[26],[27],[35] | 
| Cost |  | $ 12,200,000 | [30] | $ 10,000,000 | [9],[35] | 
| Investment, Identifier [Axis]: Frontier Financial Group Inc. – Convertible Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 6.00% | [1],[2],[3],[4],[22],[39] | 6.00% | [5],[6],[7],[8],[23],[40] | 
| Investments owned, fair value |  | $ 32,000 | [22],[39] | $ 55,000 | [23],[40] | 
| Principal amount |  | 198,000 | [22],[24],[25],[39] | 198,000 | [23],[26],[27],[40] | 
| Cost |  | 198,000 | [22],[39] | 198,000 | [23],[40] | 
| Investment, Identifier [Axis]: Frontier Financial Group Inc. – Preferred Stock |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 0 | [17],[22] | 0 | [20],[23] | 
| Cost |  | $ 500,000 | [17],[22] | $ 500,000 | [20],[23] | 
| Shares |  | 766 | [17],[22],[24],[25] | 766 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: Frontier Financial Group Inc. – Preferred Stock Warrant |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | $ 0 | [17],[22] | $ 0 | [20],[23] | 
| Cost |  | $ 0 | [17],[22] | $ 0 | [20],[23] | 
| Shares |  | 168 | [17],[22],[24],[25] | 168 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: Funko Acquisition Holdings, LLC(S) – Common Units |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | $ 31,000 | [17],[32],[41] | $ 58,000 | [20],[33],[42] | 
| Cost |  | $ 22,000 | [17],[32],[41] | $ 22,000 | [20],[33],[42] | 
| Shares |  | 4,239 | [17],[24],[25],[32],[41] | 4,239 | [20],[26],[27],[33],[42] | 
| Investment, Identifier [Axis]: GFRC 360, LLC – Common Stock Warrants |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | $ 0 | [17],[22] | $ 0 | [20],[23] | 
| Cost |  | $ 0 | [17],[22] | $ 0 | [20],[23] | 
| Investment, Identifier [Axis]: GFRC 360, LLC – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 8.00% | [1],[2],[3],[4],[30] | 8.00% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 13.10% | [1],[2],[3],[4],[30] | 11.10% | [5],[6],[7],[8],[9] | 
| Line of credit facility, available |  | $ 50,000 | [1],[2],[3],[4],[30] | $ 500,000 | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | 1,076,000 | [30] | 681,000 | [9] | 
| Principal amount |  | 1,150,000 | [24],[25],[30] | 700,000 | [9],[26],[27] | 
| Cost |  | 1,150,000 | [30] | 700,000 | [9] | 
| Investment, Identifier [Axis]: GFRC 360, LLC – Preferred Stock |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 263,000 | [17],[22] | 551,000 | [20],[23] | 
| Cost |  | $ 1,025,000 | [17],[22] | $ 1,025,000 | [20],[23] | 
| Shares |  | 1,000 | [17],[22],[24],[25] | 1,000 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: GFRC 360, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 8.00% | [1],[2],[3],[4],[30] | 8.00% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 13.10% | [1],[2],[3],[4],[30] | 11.10% | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | $ 936,000 | [30] | $ 973,000 | [9] | 
| Principal amount |  | 1,000,000 | [24],[25],[30] | 1,000,000 | [9],[26],[27] | 
| Cost |  | 1,000,000 | [30] | 1,000,000 | [9] | 
| Investment, Identifier [Axis]: GSM MidCo LLC – Common Stock |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 1,118,000 | [17],[22] | 1,359,000 | [20],[23] | 
| Cost |  | $ 767,000 | [17],[22] | $ 767,000 | [20],[23] | 
| Shares |  | 767 | [17],[22],[24],[25] | 767 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: Giving Home Health Care, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, interest rate, paid in cash |  | 12.50% | [1],[2],[3],[4],[30],[39] | 12.50% | [5],[6],[7],[8],[9],[40] | 
| Investments owned, fair value |  | $ 28,728,000 | [30],[39] | $ 28,800,000 | [9],[40] | 
| Principal amount |  | 28,800,000 | [24],[25],[30],[39] | 28,800,000 | [9],[26],[27],[40] | 
| Cost |  | 28,800,000 | [30],[39] | 28,800,000 | [9],[40] | 
| Investment, Identifier [Axis]: Giving Home Health Care, LLC – Warrant |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 2,415,000 | [17],[22] | 19,000 | [20],[23] | 
| Cost |  | $ 19,000 | [17],[22] | $ 19,000 | [20],[23] | 
| Shares |  | 10,667 | [17],[22],[24],[25] | 10,667 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: Gray Matter Systems, LLC – Delayed Draw Term Loan |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, interest rate, paid in cash | [5],[6],[7],[8],[9],[40] |  |  | 11.30% |  | 
| Line of credit facility, available | [5],[6],[7],[8],[9],[40] |  |  | $ 4,000,000 |  | 
| Investments owned, fair value | [9],[40] |  |  | 2,481,000 |  | 
| Principal amount | [9],[26],[27],[40] |  |  | 2,500,000 |  | 
| Cost | [9],[40] |  |  | $ 2,476,000 |  | 
| Investment, Identifier [Axis]: Gray Matter Systems, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30],[39] | 11.30% |  |  |  | 
| Investment, interest rate, paid in cash | [5],[6],[7],[8],[9],[40] |  |  | 11.30% |  | 
| Investments owned, fair value |  | $ 8,589,000 | [30],[39] | $ 2,084,000 | [9],[40] | 
| Principal amount |  | 8,600,000 | [24],[25],[30],[39] | 2,100,000 | [9],[26],[27],[40] | 
| Cost |  | $ 8,553,000 | [30],[39] | $ 2,069,000 | [9],[40] | 
| Investment, Identifier [Axis]: HH-Inspire Acquisition, Inc. – Delayed Draw Term Loan |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [5],[6],[7],[8],[9],[35] |  |  | 6.80% |  | 
| Investment, interest rate, paid in cash | [5],[6],[7],[8],[9],[35] |  |  | 9.90% |  | 
| Line of credit facility, available | [5],[6],[7],[8],[9],[35] |  |  | $ 0 |  | 
| Investments owned, fair value | [9],[35] |  |  | 9,925,000 |  | 
| Principal amount | [9],[26],[27],[35] |  |  | 10,000,000 |  | 
| Cost | [9],[35] |  |  | $ 10,000,000 |  | 
| Investment, Identifier [Axis]: HH-Inspire Acquisition, Inc. – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 8.00% | [1],[2],[3],[4],[30],[34] | 6.80% | [5],[6],[7],[8],[9],[35] | 
| Investment, interest rate, paid in cash |  | 13.30% | [1],[2],[3],[4],[30],[34] | 9.90% | [5],[6],[7],[8],[9],[35] | 
| Line of credit facility, available |  | $ 1,212,000 | [1],[2],[3],[4],[30],[34] | $ 1,500,000 | [5],[6],[7],[8],[9],[35] | 
| Investments owned, fair value |  | 624,000 | [30],[34] | 1,489,000 | [9],[35] | 
| Principal amount |  | 624,000 | [24],[25],[30],[34] | 1,500,000 | [9],[26],[27],[35] | 
| Cost |  | 624,000 | [30],[34] | 1,500,000 | [9],[35] | 
| Investment, Identifier [Axis]: HH-Inspire Acquisition, Inc. – Preferred Stock |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 4,213,000 | [17],[22] | 945,000 | [20],[23] | 
| Cost |  | $ 2,251,000 | [17],[22] | $ 956,000 | [20],[23] | 
| Shares |  | 1,329,054 | [17],[22],[24],[25] | 854,848 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: HH-Inspire Acquisition, Inc. – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30],[34] | 8.00% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30],[34] | 13.30% |  |  |  | 
| Investment, Identifier [Axis]: HH-Inspire Acquisition, Inc. – Term Debt 1 |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [5],[6],[7],[8],[9],[35] |  |  | 6.80% |  | 
| Investment, interest rate, paid in cash | [5],[6],[7],[8],[9],[35] |  |  | 9.90% |  | 
| Investments owned, fair value |  | $ 16,013,000 | [30],[34] | $ 15,880,000 | [9],[35] | 
| Principal amount |  | 16,013,000 | [24],[25],[30],[34] | 16,000,000 | [9],[26],[27],[35] | 
| Cost |  | 16,013,000 | [30],[34] | $ 16,000,000 | [9],[35] | 
| Investment, Identifier [Axis]: HH-Inspire Acquisition, Inc. – Term Debt 2 |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [5],[6],[7],[8],[9],[35] |  |  | 6.80% |  | 
| Investment, interest rate, paid in cash | [5],[6],[7],[8],[9],[35] |  |  | 9.90% |  | 
| Investments owned, fair value |  | 3,225,000 | [30],[34] | $ 7,940,000 | [9],[35] | 
| Principal amount |  | 3,225,000 | [24],[25],[30],[34] | 8,000,000 | [9],[26],[27],[35] | 
| Cost |  | 3,225,000 | [30],[34] | 8,000,000 | [9],[35] | 
| Investment, Identifier [Axis]: Imperative Holdings Corporation – Preferred Equity Units |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 1,656,000 | [17],[22] | 2,028,000 | [20],[23] | 
| Cost |  | $ 488,000 | [17],[22] | $ 632,000 | [20],[23] | 
| Shares |  | 972,569 | [17],[22],[24],[25] | 1,474,225 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: Imperative Holdings Corporation – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 9.80% | [1],[2],[3],[4],[30] | 10.30% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 14.90% | [1],[2],[3],[4],[30] | 13.40% | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | $ 21,493,000 | [30] | $ 23,295,000 | [9] | 
| Principal amount |  | 21,765,000 | [24],[25],[30] | 24,016,000 | [9],[26],[27] | 
| Cost |  | $ 21,611,000 | [30] | 23,968,000 | [9] | 
| Investment, Identifier [Axis]: LWO Acquisitions Company LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value | [23],[43] |  |  | 0 |  | 
| Principal amount | [23],[26],[27],[43] |  |  | 95,000 |  | 
| Cost | [23],[43] |  |  | 95,000 |  | 
| Investment, Identifier [Axis]: Leadpoint Business Services, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30] | 8.50% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30] | 13.60% |  |  |  | 
| Investments owned, fair value | [30] | $ 13,365,000 |  |  |  | 
| Principal amount | [24],[25],[30] | 13,500,000 |  |  |  | 
| Cost | [30] | $ 13,500,000 |  |  |  | 
| Investment, Identifier [Axis]: Lonestar EMS, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, interest rate, paid in kind | [1],[2],[3],[4],[22],[39] | 8.00% |  |  |  | 
| Investments owned, fair value | [22],[39] | $ 3,847,000 |  |  |  | 
| Principal amount | [22],[24],[25],[39] | 3,847,000 |  |  |  | 
| Cost | [22],[39] | 3,847,000 |  |  |  | 
| Investment, Identifier [Axis]: Lonestar EMS, LLC – Common Units |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 0 | [17],[22] | 0 | [20],[23] | 
| Cost |  | 6,750,000 | [17],[22] | $ 6,750,000 | [20],[23] | 
| Investment, Identifier [Axis]: Lonestar EMS, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, interest rate, paid in cash | [5],[6],[7],[8],[23],[40] |  |  | 8.00% |  | 
| Investments owned, fair value | [23],[40] |  |  | $ 3,030,000 |  | 
| Principal amount | [23],[26],[27],[40] |  |  | 3,250,000 |  | 
| Cost | [23],[40] |  |  | $ 3,250,000 |  | 
| Investment, Identifier [Axis]: MCG Energy Solutions, LLC – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [5],[6],[7],[8],[9] |  |  | 7.50% |  | 
| Investment, interest rate, paid in cash | [5],[6],[7],[8],[9] |  |  | 10.60% |  | 
| Line of credit facility, available | [5],[6],[7],[8],[9] |  |  | $ 3,000,000 |  | 
| Investments owned, fair value | [9] |  |  | 0 |  | 
| Principal amount | [9],[26],[27] |  |  | 0 |  | 
| Cost | [9] |  |  | 0 |  | 
| Investment, Identifier [Axis]: MCG Energy Solutions, LLC – Preferred Stock |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 8,904,000 | [22] | 8,151,000 | [23] | 
| Cost |  | $ 7,000,000 | [22] | $ 7,000,000 | [23] | 
| Shares |  | 7,000,000 | [22],[24],[25] | 7,000,000 | [23],[26],[27] | 
| Investment, Identifier [Axis]: MCG Energy Solutions, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 7.60% | [1],[2],[3],[4],[30] | 7.50% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 12.70% | [1],[2],[3],[4],[30] | 10.60% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in kind |  | 3.50% | [1],[2],[3],[4],[30] | 3.50% | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | $ 18,226,000 | [30] | $ 19,779,000 | [9] | 
| Principal amount |  | 20,111,000 | [24],[25],[30] | 20,820,000 | [9],[26],[27] | 
| Cost |  | $ 20,068,000 | [30] | 20,820,000 | [9] | 
| Investment, Identifier [Axis]: NeoGarf Solutions LLC - Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30] | 7.00% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30] | 11.00% |  |  |  | 
| Investment, interest rate, paid in kind | [1],[2],[3],[4],[30] | 1.10% |  |  |  | 
| Line of credit facility, available | [1],[2],[3],[4],[30] | $ 4,500,000 |  |  |  | 
| Investment, Identifier [Axis]: NeoGraf Solutions LLC – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value | [30] | 0 |  |  |  | 
| Principal amount | [24],[25],[30] | 0 |  |  |  | 
| Cost | [30] | $ 0 |  |  |  | 
| Investment, Identifier [Axis]: NeoGraf Solutions LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30] | 7.00% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30] | 11.00% |  |  |  | 
| Investment, interest rate, paid in kind | [1],[2],[3],[4],[30] | 1.10% |  |  |  | 
| Investments owned, fair value | [30] | $ 26,258,000 |  |  |  | 
| Principal amount | [24],[25],[30] | 27,070,000 |  |  |  | 
| Cost | [30] | $ 27,070,000 |  |  |  | 
| Investment, Identifier [Axis]: NetFortris Corp. – Preferred Stock |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value | [20],[23] |  |  | 469,000 |  | 
| Cost | [20],[23] |  |  | $ 789,000 |  | 
| Shares | [20],[23],[26],[27] |  |  | 7,890,860 |  | 
| Investment, Identifier [Axis]: OCI, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30] | 7.50% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30] | 12.60% |  |  |  | 
| Investments owned, fair value | [30] | $ 20,000,000 |  |  |  | 
| Principal amount | [24],[25],[30] | 20,000,000 |  |  |  | 
| Cost | [30] | $ 20,000,000 |  |  |  | 
| Investment, Identifier [Axis]: OCI, LLC – Term Debt 1 |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30],[39] | 7.00% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30],[39] | 7.00% |  |  |  | 
| Investments owned, fair value | [30],[39] | $ 2,000,000 |  |  |  | 
| Principal amount | [24],[25],[30],[39] | 2,000,000 |  |  |  | 
| Cost | [30],[39] | $ 2,000,000 |  |  |  | 
| Investment, Identifier [Axis]: Ohio Armor Holdings, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 8.00% | [1],[2],[3],[4],[30] | 8.00% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 13.10% | [1],[2],[3],[4],[30] | 11.10% | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | $ 17,670,000 | [30] | $ 18,558,000 | [9] | 
| Principal amount |  | 18,031,000 | [24],[25],[30] | 18,913,000 | [9],[26],[27] | 
| Cost |  | 18,013,000 | [30] | 18,913,000 | [9] | 
| Investment, Identifier [Axis]: PIC 360, LLC – Common Equity Units |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 256,000 | [17],[22] | 3,454,000 | [20],[23] | 
| Cost |  | $ 1,000 | [17],[22] | $ 1,000 | [20],[23] | 
| Shares |  | 750 | [17],[22],[24],[25] | 750 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: Pansophic Learning, Ltd. – Term Debt 1 |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 7.50% | [1],[2],[3],[4],[30] | 7.30% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 12.80% | [1],[2],[3],[4],[30] | 10.40% | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | $ 28,000,000 | [30] | $ 27,825,000 | [9] | 
| Principal amount |  | 28,000,000 | [24],[25],[30] | 28,000,000 | [9],[26],[27] | 
| Cost |  | $ 27,966,000 | [30] | $ 27,961,000 | [9] | 
| Investment, Identifier [Axis]: Pansophic Learning, Ltd. – Term Debt 2 |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 7.50% | [1],[2],[3],[4],[30] | 7.30% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 12.80% | [1],[2],[3],[4],[30] | 10.40% | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | $ 5,000,000 | [30] | $ 4,969,000 | [9] | 
| Principal amount |  | 5,000,000 | [24],[25],[30] | 5,000,000 | [9],[26],[27] | 
| Cost |  | 4,994,000 | [30] | $ 4,993,000 | [9] | 
| Investment, Identifier [Axis]: R2i Holdings, LLC – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, interest rate, paid in kind | [5],[6],[7],[8],[40],[44] |  |  | 8.00% |  | 
| Line of credit facility, available | [5],[6],[7],[8],[40],[44] |  |  | $ 1,171,000 |  | 
| Investments owned, fair value | [40],[44] |  |  | 829,000 |  | 
| Principal amount | [26],[27],[40],[44] |  |  | 829,000 |  | 
| Cost | [40],[44] |  |  | $ 829,000 |  | 
| Investment, Identifier [Axis]: R2i Holdings, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, interest rate, paid in kind | [5],[6],[7],[8],[40],[44] |  |  | 8.00% |  | 
| Investments owned, fair value | [40],[44] |  |  | $ 18,000,000 |  | 
| Principal amount | [26],[27],[40],[44] |  |  | 18,000,000 |  | 
| Cost | [40],[44] |  |  | $ 18,000,000 |  | 
| Investment, Identifier [Axis]: Salt & Straw, LLC |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value | [17],[22] | 0 |  |  |  | 
| Cost | [17],[22] | $ 0 |  |  |  | 
| Investment, Identifier [Axis]: Salt & Straw, LLC – Delayed Draw Term Loan |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 9.10% | [1],[2],[3],[4],[30] | 8.00% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 14.20% | [1],[2],[3],[4],[30] | 11.10% | [5],[6],[7],[8],[9] | 
| Line of credit facility, available |  | $ 3,000,000 | [1],[2],[3],[4],[30] | $ 11,500,000 | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | 8,118,000 | [30] | 0 | [9] | 
| Principal amount |  | 8,500,000 | [24],[25],[30] | 0 | [9],[26],[27] | 
| Cost |  | $ 8,430,000 | [30] | $ 0 | [9] | 
| Investment, Identifier [Axis]: Salt & Straw, LLC – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 9.10% | [1],[2],[3],[4],[30] | 8.00% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 14.20% | [1],[2],[3],[4],[30] | 11.10% | [5],[6],[7],[8],[9] | 
| Line of credit facility, available |  | $ 60,000 | [1],[2],[3],[4],[30] | $ 1,200,000 | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | 1,853,000 | [30] | 800,000 | [9] | 
| Principal amount |  | 1,940,000 | [24],[25],[30] | 800,000 | [9],[26],[27] | 
| Cost |  | 1,940,000 | [30] | 800,000 | [9] | 
| Investment, Identifier [Axis]: Salvo Technologies, Inc. – Preferred Stock |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 2,011,000 | [17],[22] | 2,584,000 | [20],[23] | 
| Cost |  | $ 2,500,000 | [17],[22] | $ 2,500,000 | [20],[23] | 
| Shares |  | 2,500 | [17],[22],[24],[25] | 2,500 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: Salvo Technologies, Inc. – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [5],[6],[7],[8],[9],[31] |  |  | 9.50% |  | 
| Investment, interest rate, paid in cash | [5],[6],[7],[8],[9],[31] |  |  | 12.50% |  | 
| Investments owned, fair value | [9],[31] |  |  | $ 11,619,000 |  | 
| Principal amount | [9],[26],[27],[31] |  |  | 11,887,000 |  | 
| Cost | [9],[31] |  |  | 11,887,000 |  | 
| Investment, Identifier [Axis]: Salvo Technologies, Inc. – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30] | 9.50% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30] | 14.60% |  |  |  | 
| Investments owned, fair value | [30] | $ 10,971,000 |  |  |  | 
| Principal amount | [24],[25],[30] | 11,797,000 |  |  |  | 
| Cost | [30] | 11,797,000 |  |  |  | 
| Investment, Identifier [Axis]: Sea Link International IRB, Inc. – Preferred Stock |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 175,000 | [17],[22] | 153,000 | [20],[23] | 
| Cost |  | $ 98,000 | [17],[22] | $ 98,000 | [20],[23] | 
| Shares |  | 98,039 | [17],[22],[24],[25] | 98,039 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: Sea Link International IRB, Inc. – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30],[39] | 11.30% |  |  |  | 
| Investment, interest rate, paid in kind |  | 2.00% | [1],[2],[3],[4],[30],[39] | 14.50% | [5],[6],[7],[8],[9],[40] | 
| Investments owned, fair value |  | $ 11,630,000 | [30],[39] | $ 11,074,000 | [9],[40] | 
| Principal amount |  | 12,021,000 | [24],[25],[30],[39] | 11,719,000 | [9],[26],[27],[40] | 
| Cost |  | 11,989,000 | [30],[39] | 11,679,000 | [9],[40] | 
| Investment, Identifier [Axis]: Sea Link International IRB, Inc.– Common Equity Units |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 322,000 | [17],[22] | 105,000 | [20],[23] | 
| Cost |  | $ 823,000 | [17],[22] | $ 823,000 | [20],[23] | 
| Shares |  | 823,333 | [17],[22],[24],[25] | 823,333 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: Sokol & Company Holdings, LLC – Common Stock |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | $ 1,581,000 | [17],[22] | $ 1,500,000 | [20],[23] | 
| Cost |  | $ 1,500,000 | [17],[22] | $ 1,500,000 | [20],[23] | 
| Shares |  | 1,500,000 | [17],[22],[24],[25] | 1,500,000 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: Sokol & Company Holdings, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [5],[6],[7],[8],[9],[31] |  |  | 7.00% |  | 
| Investment, interest rate, paid in cash | [5],[6],[7],[8],[9],[31] |  |  | 10.00% |  | 
| Investments owned, fair value | [9],[31] |  |  | $ 13,500,000 |  | 
| Principal amount | [9],[26],[27],[31] |  |  | 13,500,000 |  | 
| Cost | [9],[31] |  |  | $ 13,500,000 |  | 
| Investment, Identifier [Axis]: Sokol & Company Holdings, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30] | 7.00% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30] | 12.10% |  |  |  | 
| Investments owned, fair value | [30] | $ 13,179,000 |  |  |  | 
| Principal amount | [24],[25],[30] | 13,500,000 |  |  |  | 
| Cost | [30] | $ 13,500,000 |  |  |  | 
| Investment, Identifier [Axis]: SpaceCo Holdings, LLC – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 7.20% | [1],[2],[3],[4],[30],[34] | 7.00% | [5],[6],[7],[8],[9],[35] | 
| Investment, interest rate, paid in cash |  | 12.40% | [1],[2],[3],[4],[30],[34] | 10.80% | [5],[6],[7],[8],[9],[35] | 
| Line of credit facility, available |  | $ 100,000 | [1],[2],[3],[4],[30],[34] | $ 100,000 | [5],[6],[7],[8],[9],[35] | 
| Investments owned, fair value |  | 1,869,000 | [30],[34] | 1,886,000 | [9],[35] | 
| Principal amount |  | 1,900,000 | [24],[25],[30],[34] | 1,900,000 | [9],[26],[27],[35] | 
| Cost |  | $ 1,900,000 | [30],[34] | $ 1,900,000 | [9],[35] | 
| Investment, Identifier [Axis]: SpaceCo Holdings, LLC – Term Deb |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [5],[6],[7],[8],[9],[35] |  |  | 7.00% |  | 
| Investment, interest rate, paid in cash | [5],[6],[7],[8],[9],[35] |  |  | 10.80% |  | 
| Investments owned, fair value | [9],[35] |  |  | $ 31,481,000 |  | 
| Principal amount | [9],[26],[27],[35] |  |  | 31,719,000 |  | 
| Cost | [9],[35] |  |  | $ 31,326,000 |  | 
| Investment, Identifier [Axis]: SpaceCo Holdings, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30],[34] | 7.20% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30],[34] | 12.40% |  |  |  | 
| Investments owned, fair value | [30],[34] | $ 29,995,000 |  |  |  | 
| Principal amount | [24],[25],[30],[34] | 30,491,000 |  |  |  | 
| Cost | [30],[34] | $ 30,136,000 |  |  |  | 
| Investment, Identifier [Axis]: Springfield, Inc. – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 10.10% | [1],[2],[3],[4],[30] | 10.00% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 15.20% | [1],[2],[3],[4],[30] | 13.10% | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | $ 29,888,000 | [30] | $ 29,738,000 | [9] | 
| Principal amount |  | 30,000,000 | [24],[25],[30] | 30,000,000 | [9],[26],[27] | 
| Cost |  | 30,000,000 | [30] | 30,000,000 | [9] | 
| Investment, Identifier [Axis]: TNCP Intermediate HoldCo, LLC – Common Equity Units |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 2,928,000 | [17],[22] | 2,337,000 | [20],[23] | 
| Cost |  | $ 500,000 | [17],[22] | $ 500,000 | [20],[23] | 
| Shares |  | 790,000 | [17],[22],[24],[25] | 790,000 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: TNCP Intermediate HoldCo, LLC – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, interest rate, paid in cash |  | 8.00% | [1],[2],[3],[4],[22],[39] | 8.00% | [5],[6],[7],[8],[23],[40] | 
| Line of credit facility, available |  | $ 1,100,000 | [1],[2],[3],[4],[22],[39] | $ 1,000,000 | [5],[6],[7],[8],[23],[40] | 
| Investments owned, fair value |  | 900,000 | [22],[39] | 1,000,000 | [23],[40] | 
| Principal amount |  | 900,000 | [22],[24],[25],[39] | 1,000,000 | [23],[26],[27],[40] | 
| Cost |  | $ 900,000 | [22],[39] | $ 1,000,000 | [23],[40] | 
| Investment, Identifier [Axis]: Tailwind Smith Cooper Intermediate Corporation – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 9.00% | [1],[2],[3],[4],[28] | 9.00% | [5],[6],[7],[8],[29] | 
| Investment, interest rate, paid in cash |  | 14.30% | [1],[2],[3],[4],[28] | 12.10% | [5],[6],[7],[8],[29] | 
| Investments owned, fair value |  | $ 4,300,000 | [28] | $ 4,313,000 | [29] | 
| Principal amount |  | 5,000,000 | [24],[25],[28] | 5,000,000 | [26],[27],[29] | 
| Cost |  | 4,849,000 | [28] | 4,829,000 | [29] | 
| Investment, Identifier [Axis]: Targus Cayman HoldCo, Ltd. – Common Stock |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value | [20],[44],[45] |  |  | 7,978,000 |  | 
| Cost | [20],[44],[45] |  |  | $ 2,062,000 |  | 
| Shares | [20],[26],[27],[44],[45] |  |  | 3,076,414 |  | 
| Investment, Identifier [Axis]: Technical Resource Management, LLC – Common Stock |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value | [17],[22] | 2,000,000 |  |  |  | 
| Cost | [17],[22] | $ 2,000,000 |  |  |  | 
| Shares | [17],[22],[24],[25] | 2,000,000 |  |  |  | 
| Investment, Identifier [Axis]: Technical Resource Management, LLC – Delayed Draw Term Loan |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30] | 8.00% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30] | 13.10% |  |  |  | 
| Line of credit facility, available | [1],[2],[3],[4],[30] | $ 2,500,000 |  |  |  | 
| Investments owned, fair value | [30] | 0 |  |  |  | 
| Principal amount | [24],[25],[30] | 0 |  |  |  | 
| Cost | [30] | $ 0 |  |  |  | 
| Investment, Identifier [Axis]: Technical Resource Management, LLC – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30] | 8.00% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30] | 13.10% |  |  |  | 
| Line of credit facility, available | [1],[2],[3],[4],[30] | $ 3,000,000 |  |  |  | 
| Investments owned, fair value | [30] | 0 |  |  |  | 
| Principal amount | [24],[25],[30] | 0 |  |  |  | 
| Cost | [30] | $ 0 |  |  |  | 
| Investment, Identifier [Axis]: Technical Resource Management, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30] | 8.00% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30] | 13.10% |  |  |  | 
| Investments owned, fair value | [30] | $ 23,000,000 |  |  |  | 
| Principal amount | [24],[25],[30] | 23,000,000 |  |  |  | 
| Cost | [30] | 23,000,000 |  |  |  | 
| Investment, Identifier [Axis]: Total Safety Holdings, LLC – Common Equity |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 119,000 | [17],[22] | $ 50,000 | [20],[23] | 
| Cost |  | $ 499,000 | [17],[22] | $ 499,000 | [20],[23] | 
| Shares |  | 435 | [17],[22],[24],[25] | 435 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: Triple H Food Processors, LLC – Common Stock |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | $ 1,311,000 | [17],[22] | $ 672,000 | [20],[23] | 
| Cost |  | $ 250,000 | [17],[22] | $ 250,000 | [20],[23] | 
| Shares |  | 250,000 | [17],[22],[24],[25] | 250,000 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: Triple H Food Processors, LLC – Preferred Stock |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | $ 135,000 | [17],[22] | $ 120,000 | [20],[23] | 
| Cost |  | $ 75,000 | [17],[22] | $ 75,000 | [20],[23] | 
| Shares |  | 75 | [17],[22],[24],[25] | 75 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: Trowbridge Chicago, LLC – Delayed Draw Term Loan |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30] | 7.00% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30] | 12.10% |  |  |  | 
| Line of credit facility, available | [1],[2],[3],[4],[30] | $ 5,250,000 |  |  |  | 
| Investments owned, fair value | [30] | 0 |  |  |  | 
| Principal amount | [24],[25],[30] | 0 |  |  |  | 
| Cost | [30] | $ 0 |  |  |  | 
| Investment, Identifier [Axis]: Trowbridge Chicago, LLC – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30] | 7.00% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30] | 12.10% |  |  |  | 
| Line of credit facility, available | [1],[2],[3],[4],[30] | $ 2,000,000 |  |  |  | 
| Investments owned, fair value | [30] | 0 |  |  |  | 
| Principal amount | [24],[25],[30] | 0 |  |  |  | 
| Cost | [30] | 0 |  |  |  | 
| Investment, Identifier [Axis]: Trowbridge Chicago, LLC – Preferred Stock |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value | [17],[22] | 750,000 |  |  |  | 
| Cost | [17],[22] | $ 750,000 |  |  |  | 
| Shares | [17],[22],[24],[25] | 242,105 |  |  |  | 
| Investment, Identifier [Axis]: Trowbridge Chicago, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30] | 7.00% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30] | 12.10% |  |  |  | 
| Investments owned, fair value | [30] | $ 5,750,000 |  |  |  | 
| Principal amount | [24],[25],[30] | 5,750,000 |  |  |  | 
| Cost | [30] | $ 5,750,000 |  |  |  | 
| Investment, Identifier [Axis]: Turn Key Health Clinics, LLC – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 7.30% | [1],[2],[3],[4],[30] | 7.30% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 12.40% | [1],[2],[3],[4],[30] | 10.40% | [5],[6],[7],[8],[9] | 
| Line of credit facility, available |  | $ 1,500,000 | [1],[2],[3],[4],[30] | $ 1,500,000 | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | 500,000 | [30] | 495,000 | [9] | 
| Principal amount |  | 500,000 | [24],[25],[30] | 500,000 | [9],[26],[27] | 
| Cost |  | $ 500,000 | [30] | $ 500,000 | [9] | 
| Investment, Identifier [Axis]: Turn Key Health Clinics, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 7.30% | [1],[2],[3],[4],[30] | 7.30% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 12.40% | [1],[2],[3],[4],[30] | 10.40% | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | $ 11,000,000 | [30] | $ 10,890,000 | [9] | 
| Principal amount |  | 11,000,000 | [24],[25],[30] | 11,000,000 | [9],[26],[27] | 
| Cost |  | $ 11,000,000 | [30] | $ 11,000,000 | [9] | 
| Investment, Identifier [Axis]: Unirac Holdings, Inc. – Delayed Draw Term Loan |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [5],[6],[7],[8],[9],[31] |  |  | 6.50% |  | 
| Investment, interest rate, paid in cash | [5],[6],[7],[8],[9],[31] |  |  | 9.50% |  | 
| Line of credit facility, available | [5],[6],[7],[8],[9],[31] |  |  | $ 2,778,000 |  | 
| Investments owned, fair value | [9],[31] |  |  | 0 |  | 
| Principal amount | [9],[26],[27],[31] |  |  | 0 |  | 
| Cost | [9],[31] |  |  | $ 0 |  | 
| Investment, Identifier [Axis]: Unirac Holdings, Inc. – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [5],[6],[7],[8],[9],[31] |  |  | 6.50% |  | 
| Investment, interest rate, paid in cash | [5],[6],[7],[8],[9],[31] |  |  | 9.50% |  | 
| Line of credit facility, available | [5],[6],[7],[8],[9],[31] |  |  | $ 2,222,000 |  | 
| Investments owned, fair value | [9],[31] |  |  | 0 |  | 
| Principal amount | [9],[26],[27],[31] |  |  | 0 |  | 
| Cost | [9],[31] |  |  | $ 0 |  | 
| Investment, Identifier [Axis]: Unirac Holdings, Inc. – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [5],[6],[7],[8],[9],[31] |  |  | 6.50% |  | 
| Investment, interest rate, paid in cash | [5],[6],[7],[8],[9] |  |  | 9.50% |  | 
| Investments owned, fair value | [9],[31] |  |  | $ 15,000,000 |  | 
| Principal amount | [9],[26],[27],[31] |  |  | 15,000,000 |  | 
| Cost | [9],[31] |  |  | $ 14,628,000 |  | 
| Investment, Identifier [Axis]: Unirac, Inc. – Delayed Draw Term Loan |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30] | 6.50% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30] | 11.60% |  |  |  | 
| Line of credit facility, available | [1],[2],[3],[4],[30] | $ 1,669,000 |  |  |  | 
| Investments owned, fair value | [30] | 1,110,000 |  |  |  | 
| Principal amount | [24],[25],[30] | 1,108,000 |  |  |  | 
| Cost | [30] | $ 1,108,000 |  |  |  | 
| Investment, Identifier [Axis]: Unirac, Inc. – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30] | 6.50% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30] | 11.60% |  |  |  | 
| Line of credit facility, available | [1],[2],[3],[4],[30] | $ 1,022,000 |  |  |  | 
| Investments owned, fair value | [30] | 1,201,000 |  |  |  | 
| Principal amount | [24],[25],[30] | 1,200,000 |  |  |  | 
| Cost | [30] | $ 1,200,000 |  |  |  | 
| Investment, Identifier [Axis]: Unirac, Inc. – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30] | 6.50% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30] | 11.60% |  |  |  | 
| Investments owned, fair value | [30] | $ 14,906,000 |  |  |  | 
| Principal amount | [24],[25],[30] | 14,888,000 |  |  |  | 
| Cost | [30] | $ 14,561,000 |  |  |  | 
| Investment, Identifier [Axis]: Viva Railings, LLC – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 7.10% | [1],[2],[3],[4],[30] | 7.00% | [5],[6],[7],[8],[9] | 
| Investment, interest rate, paid in cash |  | 12.20% | [1],[2],[3],[4],[30] | 10.10% | [5],[6],[7],[8],[9] | 
| Line of credit facility, available |  | $ 4,000,000 | [1],[2],[3],[4],[30] | $ 4,000,000 | [5],[6],[7],[8],[9] | 
| Investments owned, fair value |  | 0 | [30] | 0 | [9] | 
| Principal amount |  | 0 | [24],[25],[30] | 0 | [9],[26],[27] | 
| Cost |  | $ 0 | [30] | $ 0 | [9] | 
| Investment, Identifier [Axis]: Viva Railings, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30] | 7.10% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30] | 12.20% |  |  |  | 
| Investments owned, fair value | [30] | $ 20,488,000 |  |  |  | 
| Principal amount | [24],[25],[30] | 20,747,000 |  |  |  | 
| Cost | [30] | 20,747,000 |  |  |  | 
| Investment, Identifier [Axis]: Viva Railings, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [5],[6],[7],[8],[9] |  |  | 7.00% |  | 
| Investment, interest rate, paid in cash | [5],[6],[7],[8],[9] |  |  | 10.10% |  | 
| Investments owned, fair value | [9] |  |  | $ 21,364,000 |  | 
| Principal amount | [9],[26],[27] |  |  | 21,800,000 |  | 
| Cost | [9] |  |  | 21,800,000 |  | 
| Investment, Identifier [Axis]: WB Xcel Holdings, LLC |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investments owned, fair value |  | 1,141,000 | [17],[22] | 5,687,000 | [20],[23] | 
| Cost |  | $ 2,750,000 | [17],[22] | $ 2,750,000 | [20],[23] | 
| Shares |  | 333 | [17],[22],[24],[25] | 333 | [20],[23],[26],[27] | 
| Investment, Identifier [Axis]: WB Xcel Holdings, LLC – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 10.50% | [1],[2],[3],[4],[22] | 10.50% | [5],[6],[7],[8],[23] | 
| Investment, interest rate, paid in cash |  | 15.60% | [1],[2],[3],[4],[22] | 13.60% | [5],[6],[7],[8],[23] | 
| Line of credit facility, available |  | $ 32,000 | [1],[2],[3],[4],[22] | $ 32,000 | [5],[6],[7],[8],[23] | 
| Investments owned, fair value |  | 1,468,000 | [22] | 1,468,000 | [23] | 
| Principal amount |  | 1,468,000 | [22],[24],[25] | 1,468,000 | [23],[26],[27] | 
| Cost |  | $ 1,468,000 | [22] | $ 1,468,000 | [23] | 
| Investment, Identifier [Axis]: WB Xcel Holdings, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread |  | 10.50% | [1],[2],[3],[4],[22] | 10.50% | [5],[6],[7],[8],[23] | 
| Investment, interest rate, paid in cash |  | 15.60% | [1],[2],[3],[4],[22] | 13.60% | [5],[6],[7],[8],[23] | 
| Investments owned, fair value |  | $ 9,850,000 | [22] | $ 9,925,000 | [23] | 
| Principal amount |  | 9,850,000 | [22],[24],[25] | 9,925,000 | [23],[26],[27] | 
| Cost |  | $ 9,850,000 | [22] | $ 9,925,000 | [23] | 
| Investment, Identifier [Axis]: WorkforceQA, LLC – Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30] | 6.50% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30] | 11.60% |  |  |  | 
| Line of credit facility, available | [1],[2],[3],[4],[30] | $ 2,000,000 |  |  |  | 
| Investments owned, fair value | [30] | 0 |  |  |  | 
| Principal amount | [24],[25],[30] | 0 |  |  |  | 
| Cost | [30] | $ 0 |  |  |  | 
| Investment, Identifier [Axis]: WorkforceQA, LLC – Term Debt |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [5],[6],[7],[8],[9],[35],[46] |  |  | 8.50% |  | 
| Investment, interest rate, paid in cash | [5],[6],[7],[8],[9],[35],[46] |  |  | 11.60% |  | 
| Investments owned, fair value | [9],[35],[46] |  |  | $ 9,975,000 |  | 
| Principal amount | [9],[26],[27],[35],[46] |  |  | 10,000,000 |  | 
| Cost | [9],[35],[46] |  |  | $ 10,000,000 |  | 
| Investment, Identifier [Axis]: WorkforceQA, LLC – Term Debt 1 |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30],[47] | 8.40% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30],[47] | 13.50% |  |  |  | 
| Investments owned, fair value | [30],[47] | $ 9,975,000 |  |  |  | 
| Principal amount | [24],[25],[30],[47] | 10,000,000 |  |  |  | 
| Cost | [30],[47] | $ 9,969,000 |  |  |  | 
| Investment, Identifier [Axis]: WorkforceQA, LLC – Term Debt 2 |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [1],[2],[3],[4],[30],[47] | 9.50% |  |  |  | 
| Investment, interest rate, paid in cash | [1],[2],[3],[4],[30],[47] | 14.60% |  |  |  | 
| Investments owned, fair value | [30],[47] | $ 1,596,000 |  |  |  | 
| Principal amount | [24],[25],[30],[47] | 1,600,000 |  |  |  | 
| Cost | [30],[47] | $ 1,595,000 |  |  |  | 
| Investment, Identifier [Axis]: WorkforceQA, LLC– Line of Credit |  |  |  |  |  | 
| Schedule of Investments [Line Items] |  |  |  |  |  | 
| Investment, reference rate and spread | [5],[6],[7],[8],[9],[35] |  |  | 6.50% |  | 
| Investment, interest rate, paid in cash | [5],[6],[7],[8],[9],[35] |  |  | 9.60% |  | 
| Line of credit facility, available | [5],[6],[7],[8],[9],[35] |  |  | $ 2,000,000 |  | 
| Investments owned, fair value | [9],[35] |  |  | 0 |  | 
| Principal amount | [9],[26],[27],[35] |  |  | 0 |  | 
| Cost | [9],[35] |  |  | $ 0 |  | 
|  | 
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