v3.26.1
Consolidated Schedule of Investments - Investments (Details) - USD ($)
Mar. 31, 2026
Dec. 31, 2025
Mar. 31, 2025
Dec. 31, 2024
Investments at cost $ 758,317,000 $ 705,269,000    
Investments at fair value 695,697,000 647,244,000    
Unrestricted Short Term Investments [Member]        
Investments at cost 36,139,000 34,711,000    
Investments at fair value 36,139,000 34,711,000    
Restricted Short Term Investments [Member]        
Investments at cost 2,634,000 2,463,000    
Investments at fair value 2,634,000 2,463,000    
Warrant [Member]        
Investments at cost 15,515,000 14,868,000    
Investments at fair value 16,685,000 16,648,000    
Equity Securities [Member]        
Investments at cost 42,655,000 42,655,000    
Investments at fair value 29,719,000 31,127,000    
U S Bank Money Market Deposit Account [Member] | Unrestricted Short Term Investments [Member]        
Investments at cost 36,139,000 34,711,000    
Investments at fair value 36,139,000 34,711,000    
U S Bank Money Market Deposit Account [Member] | Restricted Short Term Investments [Member]        
Investments at cost 2,634,000 2,463,000    
Investments at fair value 2,634,000 2,463,000    
Biotechnology Sector [Member]        
Investments at cost 121,373,000 94,280,000    
Investments at fair value 88,688,000 61,829,000    
Medical Device Sector [Member]        
Investments at cost 254,995,000 227,893,000    
Investments at fair value 249,545,000 222,485,000    
Software Sector [Member]        
Investments at cost 197,406,000 199,608,000    
Investments at fair value 187,173,000 190,911,000    
Diagnostics Sector [Member]        
Investments at cost 11,772,000 11,553,000    
Investments at fair value 11,573,000 11,369,000    
Other Sustainability Sector [Member]        
Investments at cost 51,164,000 50,321,000    
Investments at fair value 50,213,000 49,315,000    
Other Healthcare Sector [Member]        
Investments at cost 38,777,000 38,668,000    
Investments at fair value 34,599,000 34,508,000    
Investment, Unaffiliated Issuer [Member]        
Investments at cost 668,376,000 616,236,000    
Investments at fair value 631,495,000 584,100,000    
Investment, Unaffiliated Issuer [Member] | Investments, Other [Member]        
Investments at cost   25,166,000    
Investments at fair value   1,958,000    
Investment, Unaffiliated Issuer [Member] | Debt Securities [Member]        
Investments at cost 619,342,000 567,690,000    
Investments at fair value 607,324,000 558,778,000    
Investment, Unaffiliated Issuer [Member] | Warrant [Member]        
Investments at cost 15,388,000 14,741,000    
Investments at fair value 16,685,000 16,648,000    
Investment, Unaffiliated Issuer [Member] | Equity Securities [Member]        
Investments at cost 8,639,000 8,639,000    
Investments at fair value 5,308,000 6,716,000    
Investment, Unaffiliated Issuer [Member] | Non Affiliate Other Investments [Member]        
Investments at cost 25,007,000      
Investments at fair value 2,178,000      
Investment, Unaffiliated Issuer [Member] | Castle Creek Biosciences, Inc [Member] | Common Stock [Member]        
Investments at cost 250,000 250,000    
Investments at fair value $ 217,000 $ 217,000    
Number of Shares (in shares) 1,162 1,162    
Investment, Unaffiliated Issuer [Member] | Kodiak Robotics, Inc. [Member] | Common Stock [Member]        
Investments at cost $ 3,100,000 $ 3,100,000    
Investments at fair value $ 2,351,000 $ 3,700,000    
Number of Shares (in shares) 338,798 338,798    
Investment, Unaffiliated Issuer [Member] | BioVaxys Technology Corp. [Member] | Common Stock [Member]        
Investments at cost $ 14,000 $ 14,000    
Investments at fair value $ 5,000 $ 11,000    
Number of Shares (in shares) 66,170 66,170    
Investment, Unaffiliated Issuer [Member] | Emalex Biosciences, Inc. [Member] | Common Stock [Member]        
Investments at cost   $ 545,000    
Investments at fair value   $ 656,000    
Number of Shares (in shares)   47,461    
Investment, Unaffiliated Issuer [Member] | Emalex Biosciences, Inc. [Member] | Preferred Stock [Member]        
Investments at cost $ 545,000      
Investments at fair value $ 656,000      
Number of Shares (in shares) 47,461      
Investment, Unaffiliated Issuer [Member] | Cognoa, Inc. [Member] | Common Stock [Member]        
Investments at cost $ 976,000 $ 976,000    
Investments at fair value $ 975,000 $ 975,000    
Number of Shares (in shares) 16,247,754 16,247,754    
Investment, Unaffiliated Issuer [Member] | Cognoa, Inc. [Member] | Preferred Stock [Member]        
Investments at cost $ 500,000 $ 500,000    
Investments at fair value $ 500,000 $ 500,000    
Number of Shares (in shares) 2,119,272 2,119,272    
Investment, Unaffiliated Issuer [Member] | Axiom Space, Inc [Member] | Preferred Stock [Member]        
Investments at cost $ 261,000 $ 261,000    
Investments at fair value $ 306,000 $ 306,000    
Number of Shares (in shares) 1,810 1,810    
Investment, Unaffiliated Issuer [Member] | Cadrenal Therapeutics, Inc. [Member] | Common Stock [Member]        
Investments at cost $ 0 $ 0    
Investments at fair value $ 204,000 $ 271,000    
Number of Shares (in shares) 40,000 40,000    
Investment, Unaffiliated Issuer [Member] | PebblePost, Inc [Member] | Preferred Stock [Member]        
Investments at cost $ 73,000 $ 73,000    
Investments at fair value $ 73,000 $ 73,000    
Number of Shares (in shares) 56,212 56,212    
Investment, Unaffiliated Issuer [Member] | SnagAJob.com, Inc [Member] | Common Stock [Member]        
Investments at cost $ 9,000 $ 9,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 82,974 82,974    
Investment, Unaffiliated Issuer [Member] | Tigo Energy, Inc. [Member] | Common Stock [Member]        
Investments at cost $ 111,000 $ 111,000    
Investments at fair value $ 21,000 $ 7,000    
Number of Shares (in shares) 5,205 5,205    
Investment, Unaffiliated Issuer [Member] | Decisyon, Inc [Member] | Preferred Stock [Member]        
Investments at cost $ 2,800,000 $ 2,800,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 280,000 280,000    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Castle Creek Biosciences, Inc [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount $ 10,000,000 $ 10,000,000    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Castle Creek Biosciences, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost 372,000 372,000    
Investments at fair value $ 177,000 $ 274,000    
Number of Shares (in shares) 13,821 13,821    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Castle Creek Biosciences, Inc [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount $ 5,500,000 $ 5,500,000    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Castle Creek Biosciences, Inc [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 5,000,000 5,000,000    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Castle Creek Biosciences, Inc [Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount 5,000,000 5,000,000    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Avalo Therapeutics, Inc. [Member] | Common Stock Warrants [Member]        
Investments at cost 311,000 311,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 149 149    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | BioVaxys Technology Corp. [Member] | Common Stock Warrants [Member]        
Investments at cost $ 5,000 $ 5,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 400,000 400,000    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Emalex Biosciences, Inc. [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount $ 417,000 $ 1,667,000    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Emalex Biosciences, Inc. [Member] | Preferred Stock Warrants [Member]        
Investments at cost 176,000 176,000    
Investments at fair value $ 410,000 $ 447,000    
Number of Shares (in shares) 110,402 110,402    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Imunon, Inc [Member] | Common Stock Warrants [Member]        
Investments at cost $ 65,000 $ 65,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 19,671 19,671    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | KSQ Therapeutics, Inc. [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount $ 4,000,000 $ 4,250,000    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | KSQ Therapeutics, Inc. [Member] | Preferred Stock Warrants [Member]        
Investments at cost 138,000 138,000    
Investments at fair value $ 74,000 $ 13,000    
Number of Shares (in shares) 134,614 134,614    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | KSQ Therapeutics, Inc. [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount $ 4,000,000 $ 4,250,000    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | KSQ Therapeutics, Inc. [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 4,000,000 4,250,000    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | KSQ Therapeutics, Inc. [Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount 4,000,000 4,250,000    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Mustang Bio, Inc [Member] | Common Stock Warrants [Member]        
Investments at cost 146,000 146,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 568 568    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Native Microbials, Inc. [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 93,000 $ 93,000    
Investments at fair value $ 4,000 $ 4,000    
Number of Shares (in shares) 178,631 178,631    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | PDS Biotechnology Corporation [Member] | Common Stock Warrants [Member]        
Investments at cost $ 161,000 $ 161,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 381,625 381,625    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Long Grove Pharmaceuticals, LLC [Member] | Term Loan, SOFR Index, One [Member]        
Principal Amount $ 10,375,000 $ 10,298,000    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Pelthos Therapeutics, Inc. [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 10,000,000      
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Pelthos Therapeutics, Inc. [Member] | Common Stock Warrants [Member]        
Investments at cost 369,000      
Investments at fair value $ 201,000      
Number of Shares (in shares) 65,488      
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Pelthos Therapeutics, Inc. [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount $ 10,000,000      
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Pelthos Therapeutics, Inc. [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 5,000,000      
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Pelthos Therapeutics, Inc. [Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount 5,000,000      
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Provivi, Inc. [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 1,822,000 1,906,000    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Provivi, Inc. [Member] | Common Stock Warrants [Member]        
Investments at cost 278,000 278,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 175,098 175,098    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Provivi, Inc. [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 312,000 $ 312,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 709,980 709,980    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Provivi, Inc. [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount $ 1,822,000 $ 1,906,000    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Provivi, Inc. [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 911,000 953,000    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Provivi, Inc. [Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount 911,000 953,000    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Provivi, Inc. [Member] | Term Loan, Prime Index, Five [Member]        
Principal Amount 911,000 953,000    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Provivi, Inc. [Member] | Term Loan, Prime Index, Six [Member]        
Principal Amount 911,000 953,000    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Stealth BioTherapeutics Inc. [Member] | Common Stock Warrants [Member]        
Investments at cost 266,000 266,000    
Investments at fair value $ 6,000 $ 6,000    
Number of Shares (in shares) 454,544 454,544    
Investment, Unaffiliated Issuer [Member] | Biotechnology Sector [Member] | Xeris Pharmaceuticals, Inc [Member] | Common Stock Warrants [Member]        
Investments at cost $ 73,000 $ 73,000    
Investments at fair value $ 434,000 $ 691,000    
Number of Shares (in shares) 126,000 126,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Spineology, Inc [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount $ 5,000,000 $ 5,000,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Spineology, Inc [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 4,250,000 4,250,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Spineology, Inc [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 4,250,000 4,250,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Spineology, Inc [Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount 2,500,000 2,500,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Avive Solutions Inc [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 5,000,000      
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Avive Solutions Inc [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 5,000,000      
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Avive Solutions Inc [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 2,500,000      
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Avive Solutions Inc [Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount 2,500,000      
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Avive Solutions Inc [Member] | Term Loan, Prime Index, Five [Member]        
Principal Amount 2,500,000      
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Avive Solutions Inc [Member] | Term Loan, Prime Index, Six [Member]        
Principal Amount 2,500,000      
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Avive Solutions Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost 86,000      
Investments at fair value $ 86,000      
Number of Shares (in shares) 1,434,720      
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Ceribell, Inc. [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount $ 5,000,000 5,000,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Ceribell, Inc. [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 5,000,000 5,000,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Ceribell, Inc. [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 4,000,000 4,000,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Ceribell, Inc. [Member] | Preferred Stock Warrants [Member]        
Investments at cost 147,000 147,000    
Investments at fair value $ 892,000 $ 1,205,000    
Number of Shares (in shares) 89,903 89,903    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Conventus Orthopaedics, Inc [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount $ 2,801,000 $ 2,801,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Conventus Orthopaedics, Inc [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 2,801,000 2,801,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Conventus Orthopaedics, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost 268,000 268,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 13,203,395 13,203,395    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Mobia Medical Inc. [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount $ 3,750,000 $ 3,750,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Mobia Medical Inc. [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 3,750,000 3,750,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Onkos Surgical, Inc. [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 10,000,000 10,000,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Onkos Surgical, Inc. [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 10,000,000 10,000,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Onkos Surgical, Inc. [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 5,000,000 5,000,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Onkos Surgical, Inc. [Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount 5,000,000 5,000,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Onkos Surgical, Inc. [Member] | Term Loan, Prime Index, Five [Member]        
Principal Amount 5,000,000 5,000,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | VERO Biotech LLC [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount   15,000,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | VERO Biotech LLC [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount   10,000,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | VERO Biotech LLC [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount   5,000,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | VERO Biotech LLC [Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount   2,500,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | InfoBionic, Inc [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 5,000,000 5,000,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | InfoBionic, Inc [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 5,000,000 5,000,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | InfoBionic, Inc [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 5,000,000 5,000,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | InfoBionic, Inc [Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount 2,500,000 2,500,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | InfoBionic, Inc [Member] | Term Loan, Prime Index, Five [Member]        
Principal Amount 2,500,000 2,500,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | InfoBionic, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost 361,000 361,000    
Investments at fair value $ 709,000 $ 705,000    
Number of Shares (in shares) 8,488,456 8,488,456    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Scientia Vascular, Inc. [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount $ 10,000,000 $ 10,000,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Scientia Vascular, Inc. [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 10,000,000 10,000,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Scientia Vascular, Inc. [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 5,000,000 5,000,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Scientia Vascular, Inc. [Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount 1,500,000 1,500,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Scientia Vascular, Inc. [Member] | Term Loan, Prime Index, Five [Member]        
Principal Amount 3,500,000 3,500,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Sonex Health, Inc. [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 10,000,000 2,500,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Sonex Health, Inc. [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 10,000,000 2,500,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Sonex Health, Inc. [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 3,750,000 5,000,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Sonex Health, Inc. [Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount 3,750,000 5,000,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Sonex Health, Inc. [Member] | Term Loan, Prime Index, Five [Member]        
Principal Amount 2,500,000 3,750,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Sonex Health, Inc. [Member] | Term Loan, Prime Index, Six [Member]        
Principal Amount 2,500,000 3,750,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Sonex Health, Inc. [Member] | Term Loan, Prime Index, Seven [Member]        
Principal Amount   3,750,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Sonex Health, Inc. [Member] | Term Loan, Prime Index, Eight [Member]        
Principal Amount   3,750,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Hyperfine Inc [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 5,000,000      
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Hyperfine Inc [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 5,000,000      
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Hyperfine Inc [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 5,000,000      
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Hyperfine Inc [Member] | Common Stock Warrants [Member]        
Investments at cost 173,000      
Investments at fair value $ 102,000      
Number of Shares (in shares) 562,500      
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | MML US, Inc [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount $ 2,584,000 2,565,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | MML US, Inc [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 2,584,000 2,565,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | MML US, Inc [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 5,168,000 5,129,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | MML US, Inc [Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount 5,168,000 5,129,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | MML US, Inc [Member] | Term Loan, Prime Index, Five [Member]        
Principal Amount 5,129,000 5,091,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | MML US, Inc [Member] | Term Loan, Prime Index, Six [Member]        
Principal Amount 5,129,000 5,091,000    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Aerin Medical, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost 66,000 66,000    
Investments at fair value $ 1,335,000 $ 1,333,000    
Number of Shares (in shares) 1,818,183 1,818,183    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Canary Medical Inc. [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 86,000 $ 86,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 12,153 12,153    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Cognoa, Inc. [Member] | Common Stock Warrants [Member]        
Investments at cost $ 0 $ 0    
Investments at fair value $ 4,000 $ 2,000    
Number of Shares (in shares) 61,170 61,170    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Cognoa, Inc. [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 162,000 $ 162,000    
Investments at fair value $ 2,000 $ 3,000    
Number of Shares (in shares) 7,152,669 7,152,669    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | CSA Medical, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 174,000 $ 174,000    
Investments at fair value $ 468,000 $ 462,000    
Number of Shares (in shares) 4,939,813 4,939,813    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | CVRx, Inc [Member] | Common Stock Warrants [Member]        
Investments at cost $ 76,000 $ 76,000    
Investments at fair value $ 62,000 $ 20,000    
Number of Shares (in shares) 47,410 47,410    
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Ossio Inc [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount $ 12,549,000      
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Ossio Inc [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 7,530,000      
Investment, Unaffiliated Issuer [Member] | Medical Device Sector [Member] | Ossio Inc [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 2,501,000      
Investment, Unaffiliated Issuer [Member] | Consumer-related Technologies [Member] | Havenly, Inc. [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 1,111,000 $ 1,111    
Investment, Unaffiliated Issuer [Member] | Consumer-related Technologies [Member] | Havenly, Inc. [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 1,667,000 1,667    
Investment, Unaffiliated Issuer [Member] | Consumer-related Technologies [Member] | Havenly, Inc. [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 3,375,000 3,375    
Investment, Unaffiliated Issuer [Member] | Consumer-related Technologies [Member] | Havenly, Inc. [Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount 2,813,000 2,813    
Investment, Unaffiliated Issuer [Member] | Consumer-related Technologies [Member] | Havenly, Inc. [Member] | Term Loan, Prime Index, Five [Member]        
Principal Amount 2,813,000 2,813    
Investment, Unaffiliated Issuer [Member] | Consumer-related Technologies [Member] | Lyrical Foods, Inc [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 2,679,000 2,679    
Investment, Unaffiliated Issuer [Member] | Consumer-related Technologies [Member] | Lyrical Foods, Inc [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 2,679,000 2,679    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Kodiak Robotics, Inc. [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 15,000,000 15,000,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Kodiak Robotics, Inc. [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 7,500,000 7,500,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Kodiak Robotics, Inc. [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 7,500,000 7,500,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | BrightInsight, Inc. [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 5,500,000 5,500,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | BrightInsight, Inc. [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 6,417,000 6,417,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | BrightInsight, Inc. [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 3,208,000 3,208,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | BrightInsight, Inc. [Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount 3,208,000 3,208,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | BrightInsight, Inc. [Member] | Term Loan, Prime Index, Five [Member]        
Principal Amount 2,750,000 2,750,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | BrightInsight, Inc. [Member] | Term Loan, Prime Index, Six [Member]        
Principal Amount 2,250,000 2,250,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | MasteryPrep, LLC [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 7,500,000 7,500,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | MasteryPrep, LLC [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 7,500,000 7,500,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Mirantis, Inc [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 4,306,000 4,583,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Mirantis, Inc [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 4,306,000 4,583,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Mirantis, Inc [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 4,306,000 4,583,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Mirantis, Inc [Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount 4,306,000 4,583,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Elligo Health Research, Inc [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 10,000,000 10,000,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Elligo Health Research, Inc [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 5,000,000 5,000,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Elligo Health Research, Inc [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 5,000,000 5,000,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Elligo Health Research, Inc [Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount 5,000,000 5,000,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Apkudo, Inc. [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 5,000,000 5,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Apkudo, Inc. [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 5,000,000 5,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Ursa Space Systems Inc. [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 2,348,000 2,500,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Ursa Space Systems Inc. [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 2,348,000 2,500,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Ursa Space Systems Inc. [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 2,348,000 2,500,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Ursa Space Systems Inc. [Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount 2,348,000 2,500,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Viken Detection Corporation [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 2,500,000 2,833,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Viken Detection Corporation [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 1,250,000 1,417,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Viken Detection Corporation [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 1,250,000 1,417,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Britecore Holdings, Inc. [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 10,000,000 10,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Britecore Holdings, Inc. [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 7,500,000 7,500    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Britecore Holdings, Inc. [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 2,500,000 2,500    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Samba TV, Inc. [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 10,039,000 10,014,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Samba TV, Inc. [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 7,529,000 7,510,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Samba TV, Inc. [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 5,019,000 5,007,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Samba TV, Inc. [Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount 2,510,000 2,503,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Crafty Holdings, Inc.[Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 5,000,000 5,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Crafty Holdings, Inc.[Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 5,000,000 5,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Crafty Holdings, Inc.[Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 5,000,000 5,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Crafty Holdings, Inc.[Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount 2,000,000 2,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Supply Network Visibility Holdings, LLC [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 2,500,000 2,500,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Supply Network Visibility Holdings, LLC [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 3,500,000 3,500,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Supply Network Visibility Holdings, LLC [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 2,500,000 2,500,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Supply Network Visibility Holdings, LLC [Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount 1,500,000 1,500,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | Supply Network Visibility Holdings, LLC [Member] | Term Loan, Prime Index, Five [Member]        
Principal Amount 5,000,000 5,000,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | DropOff, Inc. [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 7,850,000 7,850    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | DropOff, Inc. [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 6,804,000 6,804    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | DropOff, Inc. [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 6,280,000 6,280    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | DropOff, Inc. [Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount 2,617,000 2,617    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | HappyCo, Inc [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 3,000,000 3,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | HappyCo, Inc [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 3,000,000 3,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | HappyCo, Inc [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 2,000,000 2,000    
Investment, Unaffiliated Issuer [Member] | Software Sector [Member] | HappyCo, Inc [Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount 2,000,000 2,000    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member]        
Investments at cost   8,344,000    
Investments at fair value   9,404,000    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Investments, Other [Member]        
Investments at cost   10,149,000    
Investments at fair value   0    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Debt Securities [Member]        
Investments at cost 203,494,000 205,442,000    
Investments at fair value 199,365,000 201,718,000    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Warrant [Member]        
Investments at cost 8,167,000      
Investments at fair value 9,442,000      
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Non Affiliate Other Investments [Member]        
Investments at cost 10,149,000      
Investments at fair value 0      
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Havenly, Inc. [Member] | Common Stock Warrants [Member]        
Investments at cost 3,463,000 3,463,000    
Investments at fair value $ 3,510,000 $ 3,510,000    
Number of Shares (in shares) 1,633,929 1,633,929    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Noodle Partners, Inc. [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 116,000 $ 116,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 84,037 84,037    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | OneNetworks, Inc. dba Finexio [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 3,000 $ 3,000    
Investments at fair value $ 2,000 $ 2,000    
Number of Shares (in shares) 184,646 184,646    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | NextCar Holding Company, Inc [Member] | Common Stock Warrants [Member]        
Investments at cost $ 97,000      
Investments at fair value $ 46,000      
Number of Shares (in shares) 31,848      
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | NextCar Holding Company, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost   $ 97,000    
Investments at fair value   $ 118,000    
Number of Shares (in shares)   31,848    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Revinate Holdings, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 44,000 $ 44,000    
Investments at fair value $ 86,000 $ 86,000    
Number of Shares (in shares) 682,034 682,034    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | SIGNiX, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 177,000 $ 177,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 186,235 186,235    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Slingshot Aerospace, Inc. [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 123,000 $ 123,000    
Investments at fair value $ 45,000 $ 45,000    
Number of Shares (in shares) 309,208 309,208    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Mirantis, Inc [Member] | Common Stock Warrants [Member]        
Investments at cost $ 223,000 $ 223,000    
Investments at fair value $ 425,000 $ 420,000    
Number of Shares (in shares) 948,275 948,275    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Supply Network Visiblity Holdings LLC [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 64,000 $ 64,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 682 682    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Topia Mobility, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 138,000 $ 138,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 30,496 30,496    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Ursa Space Systems Inc. [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 151,000 $ 151,000    
Investments at fair value $ 144,000 $ 169,000    
Number of Shares (in shares) 1,075,072 1,075,072    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Viken Detection Corporation [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 120,000 $ 120,000    
Investments at fair value $ 316,000 $ 314,000    
Number of Shares (in shares) 345,443 345,443    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Britecore Holdings, Inc. [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 137,000 $ 137,000    
Investments at fair value $ 451,000 $ 229,000    
Number of Shares (in shares) 194,570 194,570    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | xAd, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost   $ 177,000    
Investments at fair value   $ 0    
Number of Shares (in shares)   4,343,348    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Crafty Holdings, Inc.[Member] | Common Stock Warrants [Member]        
Investments at cost $ 138,000 $ 138,000    
Investments at fair value $ 178,000 $ 178,000    
Number of Shares (in shares) 260,972 260,972    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | DropOff, Inc. [Member] | Common Stock Warrants [Member]        
Investments at cost $ 455,000 $ 455,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 723,228 723,228    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Axiom Space, Inc [Member] | Common Stock Warrants [Member]        
Investments at cost $ 50,000 $ 50,000    
Investments at fair value $ 38,000 $ 33,000    
Number of Shares (in shares) 2,654 2,654    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | HappyCo, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 26,000 $ 26,000    
Investments at fair value $ 20,000 $ 20,000    
Number of Shares (in shares) 96,228 96,228    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Intelepeer Holdings, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 138,000 $ 138,000    
Investments at fair value $ 2,737,000 $ 2,730,000    
Number of Shares (in shares) 2,936,535 2,936,535    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Better Place Forests Co. [Member] | Investments, Other [Member]        
Investments at cost   $ 10,149,000    
Investments at fair value   0    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Better Place Forests Co. [Member] | Non Affiliate Other Investments [Member]        
Investments at cost $ 10,149,000      
Investments at fair value 0      
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Alula Holdings, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost 93,000 93,000    
Investments at fair value $ 7,000 $ 6,000    
Number of Shares (in shares) 20,000 20,000    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | CAMP NYC, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 57,000 $ 57,000    
Investments at fair value $ 77,000 $ 76,000    
Number of Shares (in shares) 224,712 224,712    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Clara Foods Co [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 30,000 $ 30,000    
Investments at fair value $ 42,000 $ 41,000    
Number of Shares (in shares) 46,745 46,745    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Divergent Technologies, Inc. [Member] | Common Stock Warrants [Member]        
Investments at cost $ 80,000 $ 80,000    
Investments at fair value $ 59,000 $ 59,000    
Number of Shares (in shares) 13,068 13,068    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Divergent Technologies, Inc. [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 538,000 $ 538,000    
Investments at fair value $ 771,000 $ 771,000    
Number of Shares (in shares) 71,014 71,014    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | MyForest Foods Co [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 41,000 $ 41,000    
Investments at fair value $ 48,000 $ 47,000    
Number of Shares (in shares) 500 500    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Primary Kids, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 57,000 $ 57,000    
Investments at fair value $ 65,000 $ 73,000    
Number of Shares (in shares) 553,778 553,778    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Quip NYC Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 325,000 $ 325,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 10,833 10,833    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Updater, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 34,000 $ 34,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 108,333 108,333    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | CPG Beyond, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 242,000 $ 242,000    
Investments at fair value $ 44,000 $ 57,000    
Number of Shares (in shares) 500,000 500,000    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Silk, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 175,000 $ 175,000    
Investments at fair value $ 177,000 $ 173,000    
Number of Shares (in shares) 394,110 394,110    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Global Worldwide LLC [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 75,000 $ 75,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 245,810 245,810    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Rocket Lawyer Incorporated [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 92,000 $ 92,000    
Investments at fair value $ 67,000 $ 151,000    
Number of Shares (in shares) 261,721 261,721    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Skillshare, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 162,000 $ 162,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 139,316 139,316    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Liqid, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 364,000 $ 364,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 344,102 344,102    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Everstream Holdings, LLC [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 82,000 $ 82,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 525,000 525,000    
Investment, Unaffiliated Issuer [Member] | Technology Sector [Member] | Lemongrass Holdings, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 57,000 $ 57,000    
Investments at fair value $ 87,000 $ 96,000    
Number of Shares (in shares) 202,616 202,616    
Investment, Unaffiliated Issuer [Member] | Life Science Segment [Member] | Investments, Other [Member]        
Investments at cost   $ 15,017,000    
Investments at fair value   1,958,000    
Investment, Unaffiliated Issuer [Member] | Life Science Segment [Member] | Debt Securities [Member]        
Investments at cost $ 327,748,000 274,306,000    
Investments at fair value 325,055,000 271,276,000    
Investment, Unaffiliated Issuer [Member] | Life Science Segment [Member] | Warrant [Member]        
Investments at cost 6,258,000 5,346,000    
Investments at fair value 6,957,000 6,964,000    
Investment, Unaffiliated Issuer [Member] | Life Science Segment [Member] | Non Affiliate Other Investments [Member]        
Investments at cost 14,858,000      
Investments at fair value 2,178,000      
Investment, Unaffiliated Issuer [Member] | Life Science Segment [Member] | Spineology, Inc [Member] | Common Stock Warrants [Member]        
Investments at cost 65,000 65,000    
Investments at fair value $ 1,000 $ 41,000    
Number of Shares (in shares) 27,139 27,139    
Investment, Unaffiliated Issuer [Member] | Life Science Segment [Member] | Spineology, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 109,000 $ 109,000    
Investments at fair value $ 16,000 $ 69,000    
Number of Shares (in shares) 45,101 45,101    
Investment, Unaffiliated Issuer [Member] | Life Science Segment [Member] | BioVaxys Technology Corp. [Member] | Royalty Agreement [Member]        
Investments at cost $ 5,073,000 $ 5,073,000    
Investments at fair value 0 0    
Investment, Unaffiliated Issuer [Member] | Life Science Segment [Member] | Magnolia Medical Technologies, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost 194,000 194,000    
Investments at fair value $ 325,000 $ 321,000    
Number of Shares (in shares) 900,043 900,043    
Investment, Unaffiliated Issuer [Member] | Life Science Segment [Member] | Meditrina, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 83,000 $ 83,000    
Investments at fair value $ 96,000 $ 95,000    
Number of Shares (in shares) 233,993 233,993    
Investment, Unaffiliated Issuer [Member] | Life Science Segment [Member] | MicroTransponder, Inc. [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 47,000      
Investments at fair value $ 89,000      
Number of Shares (in shares) 103,172      
Investment, Unaffiliated Issuer [Member] | Life Science Segment [Member] | Mobia Medical Inc. [Member] | Preferred Stock Warrants [Member]        
Investments at cost   $ 47,000    
Investments at fair value   $ 47,000    
Number of Shares (in shares)   103,172    
Investment, Unaffiliated Issuer [Member] | Life Science Segment [Member] | Onkos Surgical, Inc. [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 192,000 $ 192,000    
Investments at fair value $ 203,000 $ 200,000    
Number of Shares (in shares) 443,674 443,674    
Investment, Unaffiliated Issuer [Member] | Life Science Segment [Member] | VERO Biotech LLC [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 379,000 $ 379,000    
Investments at fair value $ 113,000 $ 111,000    
Number of Shares (in shares) 3,701 3,701    
Investment, Unaffiliated Issuer [Member] | Life Science Segment [Member] | Scientia Vascular, Inc. [Member] | Common Stock Warrants [Member]        
Investments at cost $ 60,000 $ 60,000    
Investments at fair value $ 101,000 $ 235,000    
Number of Shares (in shares) 24,000 24,000    
Investment, Unaffiliated Issuer [Member] | Life Science Segment [Member] | Scientia Vascular, Inc. [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 206,000 $ 206,000    
Investments at fair value $ 734,000 $ 481,000    
Number of Shares (in shares) 49,157 49,157    
Investment, Unaffiliated Issuer [Member] | Life Science Segment [Member] | Sonex Health, Inc. [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 443,000 $ 275,000    
Investments at fair value $ 197,000 $ 199,000    
Number of Shares (in shares) 5,592,571 2,637,133    
Investment, Unaffiliated Issuer [Member] | Life Science Segment [Member] | Aerobiotix, LLC [Member] | Royalty Agreement [Member]        
Investments at cost $ 1,372,000 $ 1,498,000    
Investments at fair value 1,827,000 1,574,000    
Investment, Unaffiliated Issuer [Member] | Life Science Segment [Member] | Lumithera, Inc. [Member] | Royalty Agreement [Member]        
Investments at cost 1,083,000 1,116,000    
Investments at fair value 351,000 384,000    
Investment, Unaffiliated Issuer [Member] | Life Science Segment [Member] | Robin Healthcare, Inc. [Member] | Royalty Agreement [Member]        
Investments at cost 7,330,000 7,330,000    
Investments at fair value 0 0    
Investment, Unaffiliated Issuer [Member] | Alternative Energy Sector [Member] | Sparkcharge, Inc. [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 2,500,000 2,500,000    
Investment, Unaffiliated Issuer [Member] | Alternative Energy Sector [Member] | Sparkcharge, Inc. [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 2,500,000 2,500,000    
Investment, Unaffiliated Issuer [Member] | Alternative Energy Sector [Member] | Sparkcharge, Inc. [Member] | Preferred Stock Warrants [Member]        
Investments at cost 45,000 45,000    
Investments at fair value $ 37,000 $ 36,000    
Number of Shares (in shares) 2,264,151 2,264,151    
Investment, Unaffiliated Issuer [Member] | Sustainability Segment [Member] | Debt Securities [Member]        
Investments at cost $ 4,874,000 $ 4,869,000    
Investments at fair value 4,874,000 4,869,000    
Investment, Unaffiliated Issuer [Member] | Sustainability Segment [Member] | Warrant [Member]        
Investments at cost 297,000 385,000    
Investments at fair value 114,000 143,000    
Investment, Unaffiliated Issuer [Member] | Sustainability Segment [Member] | New Aerofarms, Inc. assignee of Aerofarms, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost 116,000 88,000    
Investments at fair value $ 116,000 $ 30,000    
Number of Shares (in shares) 34,066 800,000    
Investment, Unaffiliated Issuer [Member] | Sustainability Segment [Member] | Pivot Bio, Inc. [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 14,000 $ 14,000    
Investments at fair value $ 2,000 $ 2,000    
Number of Shares (in shares) 210,418 210,418    
Investment, Unaffiliated Issuer [Member] | Sustainability Segment [Member] | LiquiGlide, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 53,000 $ 53,000    
Investments at fair value $ 47,000 $ 47,000    
Number of Shares (in shares) 122,717 122,717    
Investment, Unaffiliated Issuer [Member] | Sustainability Segment [Member] | Temperpack Technologies, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 185,000 $ 185,000    
Investments at fair value $ 28,000 $ 28,000    
Number of Shares (in shares) 66,605 66,605    
Investment, Unaffiliated Issuer [Member] | Other Healthcare Sector [Member] | GT Medical Technologies, Inc. [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount $ 3,750,000 $ 3,750,000    
Investment, Unaffiliated Issuer [Member] | Other Healthcare Sector [Member] | GT Medical Technologies, Inc. [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 3,750,000 3,750,000    
Investment, Unaffiliated Issuer [Member] | Other Healthcare Sector [Member] | GT Medical Technologies, Inc. [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 7,500,000 7,500,000    
Investment, Unaffiliated Issuer [Member] | Other Healthcare Sector [Member] | Hometeam Technologies, Inc [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount 4,821,000 4,821,000    
Investment, Unaffiliated Issuer [Member] | Other Healthcare Sector [Member] | Hometeam Technologies, Inc [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 4,821,000 4,821,000    
Investment, Unaffiliated Issuer [Member] | Other Healthcare Sector [Member] | Hometeam Technologies, Inc [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 4,821,000 4,821,000    
Investment, Unaffiliated Issuer [Member] | Other Healthcare Sector [Member] | Hometeam Technologies, Inc [Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount 4,821,000 4,821,000    
Investment, Unaffiliated Issuer [Member] | Other Healthcare Sector [Member] | Hometeam Technologies, Inc [Member] | Term Loan, Prime Index, Five [Member]        
Principal Amount 4,821,000 4,821,000    
Investment, Unaffiliated Issuer [Member] | Healthcare Information and Services Segment [Member] | Debt Securities [Member]        
Investments at cost 83,226,000 83,073,000    
Investments at fair value 78,030,000 80,915,000    
Investment, Unaffiliated Issuer [Member] | Healthcare Information and Services Segment [Member] | Warrant [Member]        
Investments at cost 666,000 666,000    
Investments at fair value 172,000 137,000    
Investment, Unaffiliated Issuer [Member] | Healthcare Information and Services Segment [Member] | BrightInsight, Inc. [Member] | Preferred Stock Warrants [Member]        
Investments at cost 168,000 168,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 232,871 232,871    
Investment, Unaffiliated Issuer [Member] | Healthcare Information and Services Segment [Member] | GT Medical Technologies, Inc. [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 144,000 $ 144,000    
Investments at fair value $ 72,000 $ 39,000    
Number of Shares (in shares) 326,640 326,640    
Investment, Unaffiliated Issuer [Member] | Healthcare Information and Services Segment [Member] | Elligo Healthcare Research, Inc. [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 191,000 $ 191,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 652,250 652,250    
Investment, Unaffiliated Issuer [Member] | Healthcare Information and Services Segment [Member] | SafelyYou, Inc [Member] | Preferred Stock Warrants [Member]        
Investments at cost $ 163,000 $ 163,000    
Investments at fair value $ 100,000 $ 98,000    
Number of Shares (in shares) 206,983 206,983    
Investment, Affiliated Issuer, Noncontrolled [Member]        
Investments at cost $ 89,941,000 $ 89,033,000    
Investments at fair value 64,202,000 63,144,000 $ 8,307,000 $ 8,307,000
Investment, Affiliated Issuer, Noncontrolled [Member] | Investments, Other [Member]        
Investments at cost 20,092,000 20,092,000    
Investments at fair value 1,486,000 1,486,000    
Investment, Affiliated Issuer, Noncontrolled [Member] | Debt Securities [Member]        
Principal Amount      
Investments at cost 35,706,000 34,798,000    
Investments at fair value 38,305,000 $ 37,247,000    
Floor      
Investment, Affiliated Issuer, Noncontrolled [Member] | Warrant [Member]        
Investments at cost 127,000 $ 127,000    
Investments at fair value 0 0    
Investment, Affiliated Issuer, Noncontrolled [Member] | Equity Securities [Member]        
Investments at cost 34,016,000 34,016,000    
Investments at fair value 24,411,000 24,411,000    
Investment, Affiliated Issuer, Noncontrolled [Member] | Hound Labs II, LLC [Member]        
Investments at fair value 11,573,000 11,369,000    
Investment, Affiliated Issuer, Noncontrolled [Member] | NextCar Holding Company, Inc [Member]        
Investments at fair value 1,005,000 1,079,000    
Investment, Affiliated Issuer, Noncontrolled [Member] | Nexii Building Solutions, Inc [Member]        
Investments at fair value 0 0    
Investment, Affiliated Issuer, Noncontrolled [Member] | Evelo Biosciences, Inc. [Member]        
Investments at fair value 1,486,000 1,486,000 8,307,000 8,307,000
Investment, Affiliated Issuer, Noncontrolled [Member] | Aulea Medical, Inc. [Member]        
Investments at fair value 0 0 $ 0 $ 0
Investment, Affiliated Issuer, Noncontrolled [Member] | Biotechnology Sector [Member] | Evelo Biosciences, Inc. [Member] | Investments, Other [Member]        
Investments at cost 20,092,000 20,092,000    
Investments at fair value 1,486,000 1,486,000    
Investment, Affiliated Issuer, Noncontrolled [Member] | Biotechnology Sector [Member] | Evelo Biosciences, Inc. [Member] | Common Stock [Member]        
Investments at cost 5,000,000 5,000,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 2,164,502 2,164,502    
Investment, Affiliated Issuer, Noncontrolled [Member] | Biotechnology Sector [Member] | Evelo Biosciences, Inc. [Member] | Warrant [Member]        
Investments at cost $ 127,000 $ 127,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 23,196 23,196    
Investment, Affiliated Issuer, Noncontrolled [Member] | Medical Device Sector [Member] | Aulea Medical, Inc. [Member] | Common Stock [Member]        
Investments at cost $ 0 $ 0    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 660,537 660,537    
Investment, Affiliated Issuer, Noncontrolled [Member] | Consumer-related Technologies [Member] | NextCar Holding Company, Inc [Member] | Term Loan, Fixed Index One [Member]        
Principal Amount $ 2,024,000 $ 2,266,000    
Investment, Affiliated Issuer, Noncontrolled [Member] | Consumer-related Technologies [Member] | NextCar Holding Company, Inc [Member] | Preferred Stock [Member]        
Investments at cost 0 0    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 2,688,971 2,688,971    
Investment, Affiliated Issuer, Noncontrolled [Member] | Diagnostics Sector [Member] | Hound Labs II, LLC [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount $ 7,008,000 $ 6,789,000    
Investment, Affiliated Issuer, Noncontrolled [Member] | Diagnostics Sector [Member] | Hound Labs II, LLC [Member] | Preferred Stock [Member]        
Investments at cost 4,764,000 4,764,000    
Investments at fair value $ 4,764,000 $ 4,764,000    
Number of Shares (in shares) 4,769 4,769    
Investment, Affiliated Issuer, Noncontrolled [Member] | Other Sustainability Sector [Member] | Nexii Building Solutions, Inc [Member] | Term Loan, Fixed Index One [Member]        
Principal Amount $ 790,000 $ 790,000    
Investment, Affiliated Issuer, Noncontrolled [Member] | Other Sustainability Sector [Member] | Nexii Building Solutions, Inc [Member] | Term Loan, Fixed Index Two [Member]        
Principal Amount 304,000 304,000    
Investment, Affiliated Issuer, Noncontrolled [Member] | Other Sustainability Sector [Member] | Nexii Building Solutions, Inc [Member] | Preferred Stock [Member]        
Investments at cost 9,751,000 9,751,000    
Investments at fair value $ 0 $ 0    
Number of Shares (in shares) 168,377 168,377    
Investment, Affiliated Issuer, Noncontrolled [Member] | Other Sustainability Sector [Member] | Shengrow, Inc. aka Soli Organic, Inc. [Member] | Term Loan, Prime Index, One [Member]        
Principal Amount $ 5,402,000 $ 5,246,000    
Investment, Affiliated Issuer, Noncontrolled [Member] | Other Sustainability Sector [Member] | Shengrow, Inc. aka Soli Organic, Inc. [Member] | Term Loan, Prime Index, Two [Member]        
Principal Amount 3,601,000 3,497,000    
Investment, Affiliated Issuer, Noncontrolled [Member] | Other Sustainability Sector [Member] | Shengrow, Inc. aka Soli Organic, Inc. [Member] | Term Loan, Prime Index, Three [Member]        
Principal Amount 1,801,000 1,749,000    
Investment, Affiliated Issuer, Noncontrolled [Member] | Other Sustainability Sector [Member] | Shengrow, Inc. aka Soli Organic, Inc. [Member] | Term Loan, Prime Index, Four [Member]        
Principal Amount 3,601,000 3,497,000    
Investment, Affiliated Issuer, Noncontrolled [Member] | Other Sustainability Sector [Member] | Shengrow, Inc. aka Soli Organic, Inc. [Member] | Term Loan, Prime Index, Five [Member]        
Principal Amount 1,801,000 1,749,000    
Investment, Affiliated Issuer, Noncontrolled [Member] | Other Sustainability Sector [Member] | Shengrow, Inc. aka Soli Organic, Inc. [Member] | Term Loan, Prime Index, Six [Member]        
Principal Amount 3,601,000 3,497,000    
Investment, Affiliated Issuer, Noncontrolled [Member] | Other Sustainability Sector [Member] | Shengrow, Inc. aka Soli Organic, Inc. [Member] | Term Loan, Prime Index, Seven [Member]        
Principal Amount 1,801,000 1,749,000    
Investment, Affiliated Issuer, Noncontrolled [Member] | Other Sustainability Sector [Member] | Shengrow, Inc. aka Soli Organic, Inc. [Member] | Revolver Loan, Prime Index, One [Member]        
Principal Amount 5,000,000 5,000,000    
Investment, Affiliated Issuer, Noncontrolled [Member] | Other Sustainability Sector [Member] | Shengrow, Inc. aka Soli Organic, Inc. [Member] | Revolver Loan, Prime Index, Two [Member]        
Principal Amount 5,000,000 5,000,000    
Investment, Affiliated Issuer, Noncontrolled [Member] | Other Sustainability Sector [Member] | Shengrow, Inc. aka Soli Organic, Inc. [Member] | Common Stock [Member]        
Investments at cost 1,292,000 1,292,000    
Investments at fair value $ 1,292,000 $ 1,292,000    
Number of Shares (in shares) 4,274,555 4,274,555    
Investment, Affiliated Issuer, Noncontrolled [Member] | Other Sustainability Sector [Member] | Shengrow, Inc. aka Soli Organic, Inc. [Member] | Preferred Stock [Member]        
Investments at cost $ 13,209,000 $ 13,209,000    
Investments at fair value $ 18,355,000 $ 18,355,000    
Number of Shares (in shares) 1,964,733 1,964,733