Quarterly report pursuant to Section 13 or 15(d)

CONSOLIDATED SCHEDULE OF INVESTMENTS

v3.22.2.2
CONSOLIDATED SCHEDULE OF INVESTMENTS
£ in Thousands
9 Months Ended 12 Months Ended
Sep. 30, 2022
USD ($)
shares
Dec. 31, 2021
USD ($)
shares
Sep. 30, 2022
GBP (£)
shares
Dec. 31, 2021
GBP (£)
shares
Sep. 30, 2021
USD ($)
Dec. 31, 2020
USD ($)
Investment Holdings [Line Items]            
Investment cost $ 2,869,469,000 $ 2,390,984,000        
Investments at Fair Value 2,825,738,000 2,434,522,000        
Equity            
Investment Holdings [Line Items]            
Investment cost 150,539,000 [1] 142,219,000 [2]        
Investments at Fair Value 134,134,000 184,710,000        
Warrant Investment            
Investment Holdings [Line Items]            
Investment cost 31,148,000 [1] 27,147,000 [2]        
Investments at Fair Value 27,159,000 38,399,000        
Investments in Securities [Member]            
Investment Holdings [Line Items]            
Investment cost [2]   2,388,952,000        
Investments at Fair Value   2,432,708,000        
Investment [Member]            
Investment Holdings [Line Items]            
Investment cost [2]   2,390,984,000        
Investments at Fair Value   2,434,522,000        
Investment Funds & Vehicles [Member]            
Investment Holdings [Line Items]            
Investment cost [1] 3,139,000          
Investments at Fair Value 3,046,000          
Senior Secured            
Investment Holdings [Line Items]            
Investments at Fair Value 2,607,006,000 $ 2,156,709,000        
Senior Secured | Blue Sprig Pediatrics, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Investment, Interest Rate, Paid in Kind   4.45%   4.45%    
Total Investments Before Cash And Cash Equivalent [Member]            
Investment Holdings [Line Items]            
Investment cost [1],[3] 2,869,469,000          
Investments at Fair Value 2,825,738,000          
Total Investments with Cash and Cash Equivalents            
Investment Holdings [Line Items]            
Investment cost [1],[3] 2,894,469,000          
Investments at Fair Value [3] 2,850,738,000          
Total investments In Securities            
Investment Holdings [Line Items]            
Investment cost [1] 2,866,330,000          
Investments at Fair Value 2,822,692,000          
Cash and Cash Equivalents | G S Financial Square Government Fund            
Investment Holdings [Line Items]            
Investment cost [1] 25,000,000          
Investments at Fair Value 25,000,000          
Money Market Funds [Member]            
Investment Holdings [Line Items]            
Investment cost [1],[3] 25,000,000          
Investments at Fair Value [3] 25,000,000          
Debt Investments            
Investment Holdings [Line Items]            
Investment cost 2,684,643,000 [1] $ 2,219,586,000 [2]        
Investments at Fair Value 2,661,399,000 2,209,599,000        
Unsecured            
Investment Holdings [Line Items]            
Investments at Fair Value 54,393,000 52,890,000        
Communications & Networking            
Investment Holdings [Line Items]            
Investments at Fair Value 101,094,000 105,490,000        
Communications & Networking | Equity            
Investment Holdings [Line Items]            
Investment cost [2]   1,230,000        
Investments at Fair Value   6,260,000        
Communications & Networking | Warrant Investment            
Investment Holdings [Line Items]            
Investment cost 541,000 [1] 418,000 [2]        
Investments at Fair Value 140,000 0        
Communications & Networking | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Investment cost 98,596,000 [1] 97,088,000 [4]        
Investments at Fair Value 100,954,000 99,230,000        
Communications & Networking | Aryaka Networks, Inc. | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost [1] 123,000          
Investments at Fair Value $ 140,000          
Investment, Acquisition Date [5] Jun. 28, 2022          
Shares | shares 229,611   229,611      
Communications & Networking | Peerless Network Holdings, Inc. | Equity            
Investment Holdings [Line Items]            
Investment cost [2]   1,230,000        
Investments at Fair Value   $ 6,260,000        
Shares | shares   1,138,328   1,138,328    
Communications & Networking | Peerless Network Holdings, Inc. | Equity | Preferred Series A            
Investment Holdings [Line Items]            
Investment cost [2]   $ 1,230,000        
Investments at Fair Value   $ 6,242,000        
Investment, Acquisition Date [6]   Apr. 11, 2008        
Shares | shares   1,135,000   1,135,000    
Communications & Networking | Peerless Network Holdings, Inc. | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost [2]   $ 0        
Investments at Fair Value   $ 18,000        
Investment, Acquisition Date [6]   Oct. 21, 2020        
Shares | shares   3,328   3,328    
Communications & Networking | Spring Mobile Solutions, Inc. | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 418,000 [1] $ 418,000 [2]        
Investments at Fair Value $ 0 $ 0        
Investment, Acquisition Date Apr. 19, 2013 [5] Apr. 19, 2013 [6]        
Shares | shares 2,834,375 2,834,375 2,834,375 2,834,375    
Communications & Networking | Senior Secured | Aryaka Networks, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2026-07   2026-07      
Investment, Basis Spread, Variable Rate [7] 3.25%   3.25%      
Investment, Interest Rate, Floor [7] 6.75%   6.75%      
Investment, Interest Rate, Paid in Kind [7] 1.05%   1.05%      
Principal Amount [8],[9],[10] $ 5,009,000          
Investment cost [1],[8],[9],[10] 4,943,000          
Investments at Fair Value [8],[9],[10] $ 4,943,000          
Communications & Networking | Senior Secured | Cytracom Holdings LLC | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2025-02 2025-02 2025-02 2025-02    
Investment, Basis Spread, Variable Rate 9.31% [7] 9.31% [11] 9.31% [7] 9.31% [11]    
Investment, Interest Rate, Floor 10.31% [7] 10.31% [11] 10.31% [7] 10.31% [11]    
Principal Amount $ 8,933,000 [10],[12],[13] $ 9,000,000 [14],[15],[16]        
Investment cost 8,776,000 [1],[10],[12],[13] 8,802,000 [4],[14],[15],[16]        
Investments at Fair Value $ 8,728,000 [10],[12],[13] $ 8,725,000 [14],[15],[16]        
Communications & Networking | Senior Secured | Rocket Lab Global Services, LLC | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2024-06 2024-06 2024-06 2024-06    
Investment Interest Rate [11]   3.25%   3.25%    
Investment, Basis Spread, Variable Rate 4.90% [7] 4.90% [11] 4.90% [7] 4.90% [11]    
Investment, Interest Rate, Floor 8.15% [7] 8.15% [11] 8.15% [7] 8.15% [11]    
Investment, Interest Rate, Paid in Kind 1.25% [7] 1.25% [11] 1.25% [7] 1.25% [11]    
Interest Rate and Floor [11]   3.25%   3.25%    
Principal Amount $ 84,314,000 [9],[12],[17],[18],[19] $ 88,542,000 [20],[21]        
Investment cost 84,877,000 [1],[9],[12],[17],[18],[19] 88,286,000 [4],[20],[21]        
Investments at Fair Value $ 87,283,000 [9],[12],[17],[18],[19] 90,505,000 [20],[21]        
Communications & Networking | Senior Secured | Exit Fee | Aryaka Networks, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Investment Interest Rate [7] 3.55%   3.55%      
Interest Rate and Floor [7] 3.55%   3.55%      
Communications & Networking | Senior Secured | Exit Fee | Rocket Lab Global Services, LLC | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Investment Interest Rate [7] 3.20%   3.20%      
Interest Rate and Floor [7] 3.20%   3.20%      
Communications & Networking | Debt Investments            
Investment Holdings [Line Items]            
Investment cost $ 98,596,000 [1] 97,088,000 [4]        
Investments at Fair Value 100,954,000 99,230,000        
Consumer & Business Products            
Investment Holdings [Line Items]            
Investments at Fair Value 25,497,000 28,099,000        
Consumer & Business Products | Equity            
Investment Holdings [Line Items]            
Investment cost 561,000 [1] 128,000 [2]        
Investments at Fair Value 185,000 447,000        
Consumer & Business Products | Warrant Investment            
Investment Holdings [Line Items]            
Investment cost 1,712,000 [1] 2,145,000 [2]        
Investments at Fair Value 1,122,000 4,354,000        
Consumer & Business Products | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Principal Amount [4]   23,162,000        
Investment cost [1] 23,774,000          
Investments at Fair Value 24,190,000 23,298,000        
Consumer & Business Products | Grove Collaborative, Inc. | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost [1],[5],[22] 433,000          
Investments at Fair Value [5],[22] $ 127,000          
Investment, Acquisition Date [5] Apr. 30, 2021          
Shares | shares [5],[22] 61,300   61,300      
Consumer & Business Products | Grove Collaborative, Inc. | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost [2]   433,000        
Investments at Fair Value   $ 326,000        
Investment, Acquisition Date [6]   Apr. 30, 2021        
Shares | shares   83,625   83,625    
Consumer & Business Products | Penumbra Brands, LLC (p.k.a. Gadget Guard) | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost [2]   $ 228,000        
Investments at Fair Value   $ 0        
Investment, Acquisition Date [6]   Jun. 03, 2014        
Shares | shares   1,662,441   1,662,441    
Consumer & Business Products | TechStyle, Inc. | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 128,000 [1] $ 128,000 [2]        
Investments at Fair Value $ 58,000 $ 447,000        
Investment, Acquisition Date Apr. 30, 2010 [5] Apr. 30, 2010 [6]        
Shares | shares 42,989 42,989 42,989 42,989    
Consumer & Business Products | TechStyle, Inc. | Warrant Investment | Preferred Series B            
Investment Holdings [Line Items]            
Investment cost [1] $ 1,101,000          
Investments at Fair Value $ 365,000          
Investment, Acquisition Date [5] Jul. 16, 2013          
Shares | shares 206,185   206,185      
Consumer & Business Products | Gadget Guard, LLC | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost [1] $ 228,000          
Investments at Fair Value $ 0          
Investment, Acquisition Date [5] Jun. 03, 2014          
Shares | shares 1,662,441   1,662,441      
Consumer & Business Products | The Neat Company | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 365,000 [1] $ 365,000 [2]        
Investments at Fair Value $ 0 $ 0        
Investment, Acquisition Date Aug. 13, 2014 [5] Aug. 13, 2014 [6]        
Shares | shares 54,054 54,054 54,054 54,054    
Consumer & Business Products | Whoop, Inc. | Warrant Investment | Preferred Series C            
Investment Holdings [Line Items]            
Investment cost $ 18,000 [1] $ 18,000 [2]        
Investments at Fair Value $ 757,000 $ 1,847,000        
Investment, Acquisition Date Jun. 27, 2018 [5] Jun. 27, 2018 [6]        
Shares | shares 686,270 686,270 686,270 686,270    
Consumer & Business Products | TechStyle, Inc. (p.k.a. Just Fabulous, Inc.) | Warrant Investment | Preferred Series B            
Investment Holdings [Line Items]            
Investment cost [2]   $ 1,101,000        
Investments at Fair Value   $ 2,181,000        
Investment, Acquisition Date [6]   Jul. 16, 2013        
Shares | shares   206,185   206,185    
Consumer & Business Products | Senior Secured | Grove Collaborative, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2025-04 2025-04 2025-04 2025-04    
Investment Interest Rate [11]   6.75%   6.75%    
Investment, Basis Spread, Variable Rate 5.50% [7] 5.50% [11] 5.50% [7] 5.50% [11]    
Investment, Interest Rate, Floor 8.75% [7] 8.75% [11] 8.75% [7] 8.75% [11]    
Interest Rate and Floor [11]   6.75%   6.75%    
Principal Amount $ 23,520,000 [8] $ 23,520,000 [23]        
Investment cost 23,774,000 [1],[8] 23,162,000 [4],[23]        
Investments at Fair Value $ 24,190,000 [8] 23,298,000 [23]        
Consumer & Business Products | Senior Secured | Exit Fee | Grove Collaborative, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Investment Interest Rate [7] 8.75%   8.75%      
Interest Rate and Floor [7] 8.75%   8.75%      
Consumer & Business Products | Debt Investments            
Investment Holdings [Line Items]            
Principal Amount [4]   23,162,000        
Investment cost [1] $ 23,774,000          
Investments at Fair Value 24,190,000 23,298,000        
Diversified Financial Services            
Investment Holdings [Line Items]            
Investments at Fair Value 72,061,000 65,073,000        
Diversified Financial Services | Equity            
Investment Holdings [Line Items]            
Investment cost 28,444,000 [1] 28,041,000 [2]        
Investments at Fair Value 38,022,000 32,608,000        
Diversified Financial Services | Debt Investments Under 1 Year Maturity            
Investment Holdings [Line Items]            
Investment cost [4]   403,000        
Investments at Fair Value   403,000        
Diversified Financial Services | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Investment cost 36,545,000 [1] 33,335,000 [4]        
Investments at Fair Value 34,039,000 32,062,000        
Diversified Financial Services | Gibraltar Business Capital, LLC | Equity            
Investment Holdings [Line Items]            
Investment cost 28,006,000 [1] 28,006,000 [2]        
Investments at Fair Value $ 15,623,000 $ 20,618,000        
Shares | shares 11,432,752 11,432,752 11,432,752 11,432,752    
Diversified Financial Services | Gibraltar Business Capital, LLC | Equity | Preferred Series A            
Investment Holdings [Line Items]            
Investment cost $ 26,122,000 [1],[24] $ 26,122,000 [2],[25]        
Investments at Fair Value $ 14,489,000 [24] $ 19,393,000 [25]        
Investment, Acquisition Date Mar. 01, 2018 [5] Mar. 01, 2018 [6],[25]        
Shares | shares 10,602,752 [24] 10,602,752 [25] 10,602,752 [24] 10,602,752 [25]    
Diversified Financial Services | Gibraltar Business Capital, LLC | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 1,884,000 [1],[24] $ 1,884,000 [2],[25]        
Investments at Fair Value $ 1,134,000 [24] $ 1,225,000 [25]        
Investment, Acquisition Date Mar. 01, 2018 [5] Mar. 01, 2018 [6],[25]        
Shares | shares 830,000 [24] 830,000 [25] 830,000 [24] 830,000 [25]    
Diversified Financial Services | Gibraltar Business Capital, LLC | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Principal Amount $ 25,000,000 $ 25,000,000        
Investment cost 24,545,000 [1] 24,485,000 [4]        
Investments at Fair Value 22,039,000 23,212,000        
Diversified Financial Services | Hercules Adviser LLC | Equity | Member Units            
Investment Holdings [Line Items]            
Investment cost 35,000 [1],[24] 35,000 [2],[25]        
Investments at Fair Value $ 21,945,000 [24] $ 11,990,000 [25]        
Investment, Acquisition Date Mar. 26, 2021 [5] Mar. 26, 2021 [6],[25]        
Shares | shares 1 [24] 1 [25] 1 [24] 1 [25]    
Diversified Financial Services | Newfront Insurance Holdings, Inc. | Equity | Preferred Series D-2            
Investment Holdings [Line Items]            
Investment cost [1] $ 403,000          
Investments at Fair Value $ 454,000          
Investment, Acquisition Date [5] Sep. 30, 2021          
Shares | shares 210,282   210,282      
Diversified Financial Services | Debt Investments            
Investment Holdings [Line Items]            
Investment cost $ 36,545,000 [1] $ 33,738,000 [4]        
Investments at Fair Value $ 34,039,000 $ 32,465,000        
Diversified Financial Services | Unsecured | Gibraltar Business Capital, LLC | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date   2026-09   2026-09    
Principal Amount [25]   $ 15,000,000        
Diversified Financial Services | Unsecured | Hercules Adviser LLC | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2025-06   2025-06      
Investment, Interest Rate, Paid in Cash [7] 5.00%   5.00%      
Principal Amount [24] $ 12,000,000          
Investment cost [1],[24] 12,000,000          
Investments at Fair Value [24] $ 12,000,000          
Diversified Financial Services | Unsecured 14.50% | Gibraltar Business Capital, LLC | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2026-09   2026-09      
Investment, Interest Rate, Paid in Cash 14.50% [7] 14.50% [11],[25] 14.50% [7] 14.50% [11],[25]    
Principal Amount [24] $ 15,000,000          
Investment cost 14,701,000 [1],[24] $ 14,662,000 [4],[25]        
Investments at Fair Value $ 13,033,000 [24] $ 13,818,000 [25]        
Diversified Financial Services | Unsecured 11.50% | Gibraltar Business Capital, LLC | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2026-09 2026-09 2026-09 2026-09    
Investment, Interest Rate, Paid in Cash 11.50% [7] 11.50% [11],[25] 11.50% [7] 11.50% [11],[25]    
Principal Amount $ 10,000,000 [24] $ 10,000,000 [25]        
Investment cost 9,844,000 [1],[24] 9,823,000 [4],[25]        
Investments at Fair Value 9,006,000 [24] $ 9,394,000 [25]        
Diversified Financial Services | Unsecured 5.00 % | Hercules Adviser LLC | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date   2023-05   2023-05    
Investment, Interest Rate, Paid in Cash [11],[25]   5.00%   5.00%    
Principal Amount [25]   $ 8,850,000        
Investment cost [4],[25]   8,850,000        
Investments at Fair Value [25]   $ 8,850,000        
Diversified Financial Services | Convertible Debt | Newfront Insurance Holdings, Inc. | Debt Investments Under 1 Year Maturity            
Investment Holdings [Line Items]            
Maturity Date   2022-08   2022-08    
Investment, Interest Rate, Floor [11],[26]   0.19%   0.19%    
Investment, Interest Rate, Paid in Kind [11],[26]   0.19%   0.19%    
Principal Amount [26]   $ 403,000        
Investment cost [4],[26]   403,000        
Investments at Fair Value [26]   403,000        
Investment Funds And Vehicles            
Investment Holdings [Line Items]            
Investment cost [2]   2,032,000        
Investments at Fair Value   1,814,000        
Investment Funds And Vehicles | Forbion Growth Opportunities Fund I C V            
Investment Holdings [Line Items]            
Investment cost [2],[15],[27],[28]   2,032,000        
Investments at Fair Value [15],[27],[28]   $ 1,814,000        
Investment, Acquisition Date [6],[27],[28]   Nov. 16, 2020        
Surgical Devices            
Investment Holdings [Line Items]            
Investments at Fair Value 1,536,000 $ 1,029,000        
Surgical Devices | Equity            
Investment Holdings [Line Items]            
Investment cost 1,941,000 [1] 1,941,000 [2]        
Investments at Fair Value 0 543,000        
Surgical Devices | Warrant Investment            
Investment Holdings [Line Items]            
Investment cost 152,000 [1] 206,000 [2]        
Investments at Fair Value 1,536,000 486,000        
Surgical Devices | Gynesonics, Inc. | Equity            
Investment Holdings [Line Items]            
Investment cost 1,941,000 [1] 1,941,000 [2]        
Investments at Fair Value $ 0 $ 543,000        
Shares | shares 9,595,178 9,595,178 9,595,178 9,595,178    
Surgical Devices | Gynesonics, Inc. | Equity | Preferred Series D            
Investment Holdings [Line Items]            
Investment cost $ 712,000 [1] $ 712,000 [2]        
Investments at Fair Value $ 0 $ 81,000        
Investment, Acquisition Date Feb. 08, 2013 [5] Feb. 08, 2013 [6]        
Shares | shares 1,991,157 1,991,157 1,991,157 1,991,157    
Surgical Devices | Gynesonics, Inc. | Equity | Preferred Series B            
Investment Holdings [Line Items]            
Investment cost $ 250,000 [1] $ 250,000 [2]        
Investments at Fair Value $ 0 $ 9,000        
Investment, Acquisition Date Jan. 18, 2007 [5] Jan. 18, 2007 [6]        
Shares | shares 219,298 219,298 219,298 219,298    
Surgical Devices | Gynesonics, Inc. | Equity | Preferred Series C            
Investment Holdings [Line Items]            
Investment cost $ 282,000 [1] $ 282,000 [2]        
Investments at Fair Value $ 0 $ 26,000        
Investment, Acquisition Date Jun. 16, 2010 [5] Jun. 16, 2010 [6]        
Shares | shares 656,538 656,538 656,538 656,538    
Surgical Devices | Gynesonics, Inc. | Equity | Preferred Series E            
Investment Holdings [Line Items]            
Investment cost $ 429,000 [1] $ 429,000 [2]        
Investments at Fair Value $ 0 $ 131,000        
Investment, Acquisition Date Jul. 14, 2015 [5] Jul. 14, 2015 [6]        
Shares | shares 2,786,367 2,786,367 2,786,367 2,786,367    
Surgical Devices | Gynesonics, Inc. | Equity | Preferred Series F            
Investment Holdings [Line Items]            
Investment cost $ 118,000 [1] $ 118,000 [2]        
Investments at Fair Value $ 0 $ 123,000        
Investment, Acquisition Date Dec. 18, 2018 [5] Dec. 18, 2018 [6]        
Shares | shares 1,523,693 1,523,693 1,523,693 1,523,693    
Surgical Devices | Gynesonics, Inc. | Equity | Series F One Preferred Stock            
Investment Holdings [Line Items]            
Investment cost $ 150,000 [1] $ 150,000 [2]        
Investments at Fair Value $ 0 $ 173,000        
Investment, Acquisition Date Dec. 18, 2018 [5] Dec. 18, 2018 [6]        
Shares | shares 2,418,125 2,418,125 2,418,125 2,418,125    
Surgical Devices | Gynesonics, Inc. | Warrant Investment | Preferred Series C            
Investment Holdings [Line Items]            
Investment cost $ 13,000 [1] $ 67,000 [2]        
Investments at Fair Value $ 0 $ 6,000        
Investment, Acquisition Date Dec. 05, 2012 [5] Feb. 08, 2012 [6]        
Shares | shares 33,670 151,123 33,670 151,123    
Surgical Devices | TransMedics Group, Inc. (p.k.a Transmedics, Inc.) | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 139,000 [1],[5] $ 139,000 [2],[6]        
Investments at Fair Value $ 1,536,000 [5] $ 480,000 [6]        
Investment, Acquisition Date Nov. 07, 2012 [5] Nov. 07, 2012        
Shares | shares 64,440 [5] 64,440 [6] 64,440 [5] 64,440 [6]    
Drug Discovery & Development            
Investment Holdings [Line Items]            
Investments at Fair Value $ 1,091,827,000 $ 967,383,000        
Drug Discovery & Development | Equity            
Investment Holdings [Line Items]            
Investment cost 42,548,000 [1] 33,401,000 [2]        
Investments at Fair Value 32,844,000 24,860,000        
Drug Discovery & Development | Warrant Investment            
Investment Holdings [Line Items]            
Investment cost 7,709,000 [1] 7,393,000 [2]        
Investments at Fair Value 4,074,000 4,745,000        
Drug Discovery & Development | Investment Funds & Vehicles [Member]            
Investment Holdings [Line Items]            
Investment cost [1] 2,758,000          
Investments at Fair Value 2,665,000          
Drug Discovery & Development | Debt Investments Under 1 Year Maturity            
Investment Holdings [Line Items]            
Investment cost 16,378,000 [1] 20,036,000 [4]        
Investments at Fair Value 16,093,000 20,036,000        
Drug Discovery & Development | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Investment cost 1,039,957,000 [1] 916,421,000 [2]        
Investments at Fair Value 1,036,151,000 915,928,000        
Drug Discovery & Development | Chemocentryx, Inc. | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost 1,000,000 [1],[5],[29] 1,000,000 [2],[6],[27]        
Investments at Fair Value $ 891,000 [5],[29] $ 628,000 [6],[27]        
Investment, Acquisition Date Jun. 15, 2020 [5] Jun. 15, 2020 [6],[27]        
Shares | shares 17,241 [5],[29] 17,241 [6],[27] 17,241 [5],[29] 17,241 [6],[27]    
Drug Discovery & Development | Akero Therapeutics, Inc. | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost [1] $ 1,000,000          
Investments at Fair Value [5],[29] $ 1,310,000          
Investment, Acquisition Date [5] Sep. 19, 2022          
Shares | shares [5],[29] 38,461   38,461      
Drug Discovery & Development | Akero Therapeutics, Inc. | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost [1],[5],[29] $ 56,000          
Investments at Fair Value [5],[29] $ 398,000          
Investment, Acquisition Date [5] Jun. 15, 2022          
Shares | shares [5],[29] 18,360   18,360      
Drug Discovery & Development | Albireo Pharma, Inc. | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 1,000,000 [1],[5],[29] $ 1,000,000 [2],[6],[27]        
Investments at Fair Value $ 484,000 [5],[29] $ 582,000 [6],[27]        
Investment, Acquisition Date Sep. 14, 2020 [5] Sep. 14, 2020 [6],[27]        
Shares | shares 25,000 [5],[29] 25,000 [6],[27] 25,000 [5],[29] 25,000 [6],[27]    
Drug Discovery & Development | Albireo Pharma, Inc. | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 61,000 [1],[5],[29] $ 61,000 [2],[6],[27]        
Investments at Fair Value $ 26,000 [5],[29] $ 42,000 [6],[27]        
Investment, Acquisition Date Jun. 08, 2020 [5] Jun. 08, 2020 [6],[27]        
Shares | shares 5,311 [5],[29] 5,311 [6],[27] 5,311 [5],[29] 5,311 [6],[27]    
Drug Discovery & Development | Aveo Pharmaceuticals, Inc. | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 1,715,000 [1],[5] $ 1,715,000 [2],[6]        
Investments at Fair Value $ 1,565,000 [5] $ 892,000 [6]        
Investment, Acquisition Date Jul. 31, 2011 [5] Jul. 31, 2011 [6]        
Shares | shares 190,179 [5] 190,179 [6] 190,179 [5] 190,179 [6]    
Drug Discovery & Development | Axsome Therapeutics, Inc. | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost [1],[5],[19],[22],[29] $ 4,165,000          
Investments at Fair Value [5],[19],[22],[29] $ 5,360,000          
Investment, Acquisition Date [5] May 09, 2022          
Shares | shares [5],[19],[22],[29] 127,021   127,021      
Drug Discovery & Development | Axsome Therapeutics, Inc. | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 880,000 [1],[5],[19],[29] $ 681,000 [2],[6],[27]        
Investments at Fair Value $ 783,000 [5],[19],[29] $ 142,000 [6],[27]        
Investment, Acquisition Date Sep. 25, 2020 [5] Sep. 25, 2020 [6],[27]        
Shares | shares 40,396 [5],[19],[22],[29] 15,541 [6],[27] 40,396 [5],[19],[22],[29] 15,541 [6],[27]    
Drug Discovery & Development | Bicycle Therapeutics PLC | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 1,871,000 [1],[5],[29],[30] $ 1,871,000 [2],[6],[27],[28]        
Investments at Fair Value $ 2,282,000 [5],[29],[30] $ 5,971,000 [6],[27],[28]        
Investment, Acquisition Date Oct. 05, 2020 [5] Oct. 05, 2020 [6],[27],[28]        
Shares | shares 98,100 [5],[29],[30] 98,100 [6],[27],[28] 98,100 [5],[29],[30] 98,100 [6],[27],[28]    
Drug Discovery & Development | BridgeBio Pharma, Inc. | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 2,255,000 [1],[5] $ 2,255,000 [2],[6]        
Investments at Fair Value $ 2,299,000 [5] $ 3,859,000 [6]        
Investment, Acquisition Date Jun. 21, 2018 [5] Jun. 21, 2018 [6]        
Shares | shares 231,329 [5] 231,329 [6] 231,329 [5] 231,329 [6]    
Drug Discovery & Development | Cellarity, Inc. | Warrant Investment | Preferred Series B            
Investment Holdings [Line Items]            
Investment cost $ 287,000 [1],[31] $ 287,000 [2],[32]        
Investments at Fair Value $ 370,000 [31] $ 287,000 [32]        
Investment, Acquisition Date Dec. 08, 2021 [5] Dec. 08, 2021 [6]        
Shares | shares 100,000 [31] 100,000 [32] 100,000 [31] 100,000 [32]    
Drug Discovery & Development | Century Therapeutics, Inc. | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 37,000 [1],[5] $ 37,000 [2],[6]        
Investments at Fair Value $ 16,000 [5] $ 64,000 [6]        
Investment, Acquisition Date Sep. 14, 2020 [5] Sep. 14, 2020 [6]        
Shares | shares 16,112 [5] 16,112 [6] 16,112 [5] 16,112 [6]    
Drug Discovery & Development | enGene, Inc. | Warrant Investment | Preferred Series 3            
Investment Holdings [Line Items]            
Investment cost [1],[29],[30] $ 72,000          
Investments at Fair Value [29],[30] $ 31,000          
Investment, Acquisition Date [5] Dec. 30, 2021          
Shares | shares [29],[30] 133,692   133,692      
Drug Discovery & Development | enGene, Inc. | Warrant Investment | Preferred Series 3 Class C            
Investment Holdings [Line Items]            
Investment cost [2],[27],[28]   $ 64,000        
Investments at Fair Value [27],[28]   $ 64,000        
Investment, Acquisition Date [6],[27],[28]   Dec. 30, 2021        
Shares | shares [27],[28]   84,714   84,714    
Drug Discovery & Development | Hibercell, Inc. | Equity | Preferred Series B            
Investment Holdings [Line Items]            
Investment cost $ 4,250,000 [1],[31] $ 4,250,000 [2],[32]        
Investments at Fair Value $ 2,917,000 [31] $ 3,264,000 [32]        
Investment, Acquisition Date May 07, 2021 [5] May 07, 2021 [6]        
Shares | shares 3,466,840 [31] 3,466,840 [32] 3,466,840 [31] 3,466,840 [32]    
Drug Discovery & Development | HilleVax, Inc. | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost [1],[5] $ 4,000,000          
Investments at Fair Value [5] $ 4,021,000          
Investment, Acquisition Date [5] May 03, 2022          
Shares | shares [5] 235,295   235,295      
Drug Discovery & Development | Humanigen, Inc. | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 800,000 [1],[5],[29] $ 800,000 [2],[6],[27]        
Investments at Fair Value $ 8,000 [5],[29] $ 161,000 [6],[27]        
Investment, Acquisition Date Mar. 31, 2021 [5] Mar. 31, 2021 [6],[27]        
Shares | shares 43,243 [5],[29] 43,243 [6],[27] 43,243 [5],[29] 43,243 [6],[27]    
Drug Discovery & Development | Kaleido Biosciences, Inc. | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost [2],[6]   $ 1,000,000        
Investments at Fair Value [6]   $ 207,000        
Investment, Acquisition Date [6]   Feb. 10, 2021        
Shares | shares [6]   86,585   86,585    
Drug Discovery & Development | Madrigal Pharmaceutical, Inc. | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost [1],[5],[29] $ 177,000          
Investments at Fair Value [5],[29] $ 214,000          
Investment, Acquisition Date [5] May 09, 2022          
Shares | shares [5],[29] 10,131   10,131      
Drug Discovery & Development | Phathom Pharmaceuticals, Inc. | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 848,000 [1],[5],[19],[29],[31] $ 848,000 [2],[6],[27],[32]        
Investments at Fair Value $ 113,000 [5],[19],[29],[31] $ 307,000 [6],[21],[27],[32]        
Investment, Acquisition Date Sep. 17, 2021 [5] Sep. 17, 2021 [6],[27]        
Shares | shares 64,687 [5],[19],[29],[31] 64,687 [6],[21],[27],[32] 64,687 [5],[19],[29],[31] 64,687 [6],[21],[27],[32]    
Drug Discovery & Development | Provention Bio, Inc. | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost [1],[5] $ 281,000          
Investments at Fair Value [5] $ 224,000          
Investment, Acquisition Date [5] Sep. 15, 2022          
Shares | shares [5] 111,934   111,934      
Drug Discovery & Development | Redshift Bioanalytics, Inc. | Warrant Investment            
Investment Holdings [Line Items]            
Investments at Fair Value [31] $ 18,000          
Drug Discovery & Development | Redshift Bioanalytics, Inc. | Warrant Investment | Preferred Series E            
Investment Holdings [Line Items]            
Investment cost [1],[31] $ 20,000          
Investment, Acquisition Date [5] Mar. 23, 2022          
Shares | shares [31] 475,510   475,510      
Drug Discovery & Development | Scynexis, Inc. | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 296,000 [1],[5] $ 188,000 [2],[6]        
Investments at Fair Value $ 47,000 [5] $ 142,000 [6]        
Investment, Acquisition Date May 14, 2021 [5] May 14, 2021 [6]        
Shares | shares 106,035 [5] 90,887 [6] 106,035 [5] 90,887 [6]    
Drug Discovery & Development | Tarsus Pharmaceuticals, Inc. | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost [1],[5],[29] $ 2,100,000          
Investments at Fair Value [5],[29] $ 2,663,000          
Investment, Acquisition Date [5] May 05, 2022          
Shares | shares [5],[29] 155,555   155,555      
Drug Discovery & Development | TG Therapeutics, Inc. | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 1,033,000 [1],[5],[18],[29] $ 1,033,000 [2],[6],[27],[33]        
Investments at Fair Value $ 335,000 [5],[18],[29] $ 2,172,000 [6],[27],[33]        
Investment, Acquisition Date Feb. 28, 2019 [5] Feb. 28, 2019 [6],[27]        
Shares | shares 231,613 [5],[18],[29] 231,613 [6],[27],[33] 231,613 [5],[18],[29] 231,613 [6],[27],[33]    
Drug Discovery & Development | Uni Qure B V | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 332,000 [1],[5],[19],[29],[30] $ 332,000 [2],[6],[21],[27],[28]        
Investments at Fair Value $ 322,000 [5],[19],[29],[30] $ 356,000 [6],[21],[27],[28]        
Investment, Acquisition Date Jan. 31, 2019 [5] Jan. 31, 2019 [6],[27],[28]        
Shares | shares 17,175 [5],[19],[29],[30] 17,175 [6],[21],[27],[28] 17,175 [5],[19],[29],[30] 17,175 [6],[21],[27],[28]    
Drug Discovery & Development | Valo Health L L C | Equity | Preferred Series B            
Investment Holdings [Line Items]            
Investment cost $ 3,000,000 [1] $ 3,000,000 [2]        
Investments at Fair Value $ 3,622,000 $ 4,650,000        
Investment, Acquisition Date Dec. 11, 2020 [5] Dec. 11, 2020 [6]        
Shares | shares 510,308 510,308 510,308 510,308    
Drug Discovery & Development | Valo Health L L C | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investments at Fair Value $ 242,000          
Investment, Acquisition Date [5] Jun. 15, 2020          
Drug Discovery & Development | Valo Health L L C | Warrant Investment | Common Units            
Investment Holdings [Line Items]            
Investment cost [1] $ 256,000          
Shares | shares 102,216   102,216      
Drug Discovery & Development | X Four Pharmaceuticals Inc | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 2,522,000 [1],[5] $ 1,641,000 [2],[6]        
Investments at Fair Value $ 1,901,000 [5] $ 454,000 [6]        
Investment, Acquisition Date Nov. 26, 2019 [5] Nov. 26, 2019 [6]        
Shares | shares 1,111,519 [5] 198,277 [6] 1,111,519 [5] 198,277 [6]    
Drug Discovery & Development | X Four Pharmaceuticals Inc | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 792,000 [1],[5] $ 673,000 [2],[6]        
Investments at Fair Value $ 628,000 [5] $ 2,000 [6]        
Investment, Acquisition Date Mar. 18, 2019 [5] Mar. 18, 2019 [6]        
Shares | shares 1,021,576 [5] 108,334 [6] 1,021,576 [5] 108,334 [6]    
Drug Discovery & Development | Applied Molecular Transport | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 42,000 [1],[5],[29] $ 42,000 [2],[6],[27]        
Investments at Fair Value $ 1,000 [5],[29] $ 14,000 [6],[27]        
Investment, Acquisition Date Apr. 06, 2021 [5] Apr. 06, 2021 [6],[27]        
Shares | shares 1,000 [5],[29] 1,000 [6],[27] 1,000 [5],[29] 1,000 [6],[27]    
Drug Discovery & Development | Avalo Therapeutics, Inc. | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 1,000,000 [1],[5] $ 1,000,000 [2],[6]        
Investments at Fair Value $ 33,000 [5] $ 202,000 [6]        
Investment, Acquisition Date Aug. 19, 2014 [5] Aug. 19, 2014 [6]        
Shares | shares 9,924 [5] 119,087 [6] 9,924 [5] 119,087 [6]    
Drug Discovery & Development | Concert Pharmaceuticals, Inc. | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 1,367,000 [1],[5],[29] $ 1,367,000 [2],[6],[27]        
Investments at Fair Value $ 474,000 [5],[29] $ 223,000 [6],[27]        
Investment, Acquisition Date Feb. 13, 2019 [5] Feb. 13, 2019 [6],[27]        
Shares | shares 70,796 [5],[29] 70,796 [6],[27] 70,796 [5],[29] 70,796 [6],[27]    
Drug Discovery & Development | Concert Pharmaceuticals, Inc. | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost [2],[6],[27]   $ 178,000        
Investments at Fair Value [6],[27]   $ 3,000        
Investment, Acquisition Date [6],[27]   Jun. 08, 2017        
Shares | shares [6],[27]   61,273   61,273    
Drug Discovery & Development | Dare Biosciences, Inc. | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 1,000,000 [1],[5] $ 1,000,000 [2],[6]        
Investments at Fair Value $ 14,000 [5] $ 27,000 [6]        
Investment, Acquisition Date Jan. 08, 2015 [5] Jan. 08, 2015 [6]        
Shares | shares 13,550 [5] 13,550 [6] 13,550 [5] 13,550 [6]    
Drug Discovery & Development | Dynavax Technologies | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 550,000 [1],[5],[29] $ 550,000 [2],[6],[27]        
Investments at Fair Value $ 209,000 [5],[29] $ 281,000 [6],[27]        
Investment, Acquisition Date Jul. 22, 2015 [5] Jul. 22, 2015 [6],[27]        
Shares | shares 20,000 [5],[29] 20,000 [6],[27] 20,000 [5],[29] 20,000 [6],[27]    
Drug Discovery & Development | NorthSea Therapeutics | Equity | Preferred Series C            
Investment Holdings [Line Items]            
Investment cost $ 2,000,000 [1],[29],[30] $ 2,000,000 [2],[27],[28]        
Investments at Fair Value $ 1,515,000 [29],[30] $ 2,000,000 [27],[28]        
Investment, Acquisition Date Dec. 15, 2021 [5] Dec. 15, 2021 [6],[27],[28]        
Shares | shares 983 [29],[30] 983 [27],[28] 983 [29],[30] 983 [27],[28]    
Drug Discovery & Development | Paratek Pharmaceuticals, Inc. | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 2,744,000 [1],[5] $ 2,744,000 [2],[6]        
Investments at Fair Value $ 196,000 [5] $ 343,000 [6]        
Investment, Acquisition Date Feb. 26, 2007 [5] Feb. 26, 2007 [6]        
Shares | shares 76,362 [5] 76,362 [6] 76,362 [5] 76,362 [6]    
Drug Discovery & Development | Paratek Pharmaceuticals, Inc. | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 520,000 [1],[5] $ 546,000 [2],[6]        
Investments at Fair Value $ 72,000 [5] $ 427,000 [6]        
Investment, Acquisition Date Aug. 01, 2018 [5] Jun. 27, 2017 [6]        
Shares | shares 426,866 [5] 432,240 [6] 426,866 [5] 432,240 [6]    
Drug Discovery & Development | Rocket Pharmaceuticals, Ltd. | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 1,500,000 [1],[5] $ 1,500,000 [2],[6]        
Investments at Fair Value $ 15,000 [5] $ 21,000 [6]        
Investment, Acquisition Date Aug. 22, 2007 [5] Aug. 22, 2007 [6]        
Shares | shares 944 [5] 944 [6] 944 [5] 944 [6]    
Drug Discovery & Development | Savara, Inc. | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 203,000 [1],[5] $ 202,000 [2],[6]        
Investments at Fair Value $ 17,000 [5] $ 14,000 [6]        
Investment, Acquisition Date Aug. 11, 2015 [5] Aug. 11, 2015 [6]        
Shares | shares 11,119 [5] 11,119 [6] 11,119 [5] 11,119 [6]    
Drug Discovery & Development | Sio Gene Therapies, Inc. | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 1,269,000 [1],[5] $ 1,269,000 [2],[6],[27]        
Investments at Fair Value $ 4,000 [5] $ 21,000 [6],[27]        
Investment, Acquisition Date Feb. 02, 2017 [5] Feb. 02, 2017 [6],[27]        
Shares | shares 16,228 [5] 16,228 [6],[27] 16,228 [5] 16,228 [6],[27]    
Drug Discovery & Development | Tricida, Inc. | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 863,000 [1],[5] $ 863,000 [2],[6]        
Investments at Fair Value $ 721,000 [5] $ 658,000 [6]        
Investment, Acquisition Date Feb. 28, 2018 [5] Feb. 28, 2018 [6]        
Shares | shares 68,816 [5] 68,816 [6] 68,816 [5] 68,816 [6]    
Drug Discovery & Development | Tricida, Inc. | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 280,000 [1],[5] $ 280,000 [2],[6]        
Investments at Fair Value $ 22,000 [5] $ 20,000 [6]        
Investment, Acquisition Date Mar. 27, 2019 [5] Mar. 27, 2019 [6]        
Shares | shares 31,352 [5] 31,352 [6] 31,352 [5] 31,352 [6]    
Drug Discovery & Development | ADMA Biologics, Inc. | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 295,000 [1],[5] $ 295,000 [2],[6]        
Investments at Fair Value $ 2,000 [5] $ 1,000 [6]        
Investment, Acquisition Date Dec. 21, 2012 [5] Dec. 21, 2012 [6]        
Shares | shares 89,750 [5] 89,750 [6] 89,750 [5] 89,750 [6]    
Drug Discovery & Development | Brickell Biotech, Inc. | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost [2],[6]   $ 119,000        
Investments at Fair Value [6]   $ 0        
Investment, Acquisition Date [6]   Feb. 18, 2016        
Shares | shares [6]   9,005   9,005    
Drug Discovery & Development | Dermavant Sciences Ltd. | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 101,000 [1],[18],[29],[30] $ 101,000 [2],[27],[33]        
Investments at Fair Value $ 104,000 [18],[29],[30] $ 354,000 [27],[33]        
Investment, Acquisition Date May 31, 2019 [5] May 31, 2019 [6],[27]        
Shares | shares 223,642 [18],[29],[30] 223,642 [27],[33] 223,642 [18],[29],[30] 223,642 [27],[33]    
Drug Discovery & Development | Evofem Biosciences, Inc. | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 266,000 [1],[5] $ 266,000 [2],[6]        
Investments at Fair Value $ 0 [5] $ 0 [6]        
Investment, Acquisition Date Jun. 11, 2014 [5] Jun. 11, 2014 [6]        
Shares | shares 520 [5] 7,806 [6] 520 [5] 7,806 [6]    
Drug Discovery & Development | Myovant Sciences, Ltd. | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 460,000 [1],[5],[29],[30] $ 460,000 [2],[6],[27]        
Investments at Fair Value $ 429,000 [5],[29],[30] $ 267,000 [6],[27]        
Investment, Acquisition Date Oct. 16, 2017 [5] Oct. 16, 2017 [6],[27]        
Shares | shares 73,710 [5],[29],[30] 73,710 [6],[27] 73,710 [5],[29],[30] 73,710 [6],[27]    
Drug Discovery & Development | Stealth Bio Therapeutics Corp. | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 158,000 [1],[5],[29],[30] $ 158,000 [2],[6],[27]        
Investments at Fair Value $ 0 [5],[29],[30] $ 0 [6],[27]        
Investment, Acquisition Date Jun. 30, 2017 [5] Jun. 30, 2017 [6],[27]        
Shares | shares 500,000 [5],[29],[30] 500,000 [6],[27] 500,000 [5],[29],[30] 500,000 [6],[27]    
Drug Discovery & Development | Yumanity Therapeutics, Inc. | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 110,000 [1],[5] $ 110,000 [2],[6]        
Investments at Fair Value $ 0 [5] $ 3,000 [6]        
Investment, Acquisition Date Dec. 20, 2019 [5] Dec. 20, 2019 [6]        
Shares | shares 15,414 [5] 15,414 [6] 15,414 [5] 15,414 [6]    
Drug Discovery & Development | Fresh Tracks Therapeutics, Inc. (p.k.a. Brickell Biotech, Inc.) | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost [1],[5] $ 119,000          
Investments at Fair Value [5] $ 0          
Investment, Acquisition Date [5] Feb. 18, 2016          
Shares | shares [5] 200   200      
Drug Discovery & Development | Forbion Growth Opportunities Fund I C V | Investment Funds & Vehicles [Member]            
Investment Holdings [Line Items]            
Investment cost [1],[10],[29],[30] $ 2,353,000          
Investments at Fair Value [10],[29],[30] $ 2,291,000          
Investment, Acquisition Date [5] Nov. 16, 2020          
Drug Discovery & Development | Forbion Growth Opportunities Fund I I C V | Investment Funds & Vehicles [Member]            
Investment Holdings [Line Items]            
Investment cost [1],[10],[29],[30] $ 405,000          
Investments at Fair Value [10],[29],[30] $ 374,000          
Investment, Acquisition Date [5] Jun. 23, 2022          
Drug Discovery & Development | Valo Health, LLC (p.k.a. Integral Health Holdings, LLC) | Warrant Investment | Common Units            
Investment Holdings [Line Items]            
Investment cost [2]   $ 256,000        
Investments at Fair Value   $ 441,000        
Investment, Acquisition Date [6]   Jun. 15, 2020        
Shares | shares   102,216   102,216    
Drug Discovery & Development | Acacia Pharma Inc. | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost $ 304,000 [1],[29],[30] $ 305,000 [2],[6],[27],[28]        
Investments at Fair Value $ 0 [29],[30] $ 6,000 [6],[27],[28]        
Investment, Acquisition Date Jun. 29, 2018 [5] Jun. 29, 2018 [6],[27],[28]        
Shares | shares 201,330 [29],[30] 201,330 [6],[27],[28] 201,330 [29],[30] 201,330 [6],[27],[28]    
Drug Discovery & Development | Genocea Biosciences Inc | Equity | Common Stock            
Investment Holdings [Line Items]            
Investment cost [2],[6]   $ 2,000,000        
Investments at Fair Value [6]   $ 32,000        
Investment, Acquisition Date [6]   Nov. 20, 2014        
Shares | shares [6]   27,933   27,933    
Drug Discovery & Development | Genocea Biosciences Inc | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost [2],[6]   $ 165,000        
Investments at Fair Value [6]   $ 1,000        
Investment, Acquisition Date [6]   Apr. 24, 2018        
Shares | shares [6]   41,176   41,176    
Drug Discovery & Development | Motif Bio P L C | Warrant Investment | Common Stock            
Investment Holdings [Line Items]            
Investment cost [2],[27]   $ 282,000        
Investments at Fair Value [27]   $ 0        
Investment, Acquisition Date [6],[27]   Jan. 27, 2020        
Shares | shares [27]   121,337,041   121,337,041    
Drug Discovery & Development | Senior Secured | Chemocentryx, Inc. | Debt Investments Under 1 Year Maturity            
Investment Holdings [Line Items]            
Maturity Date 2022-12 2022-12 2022-12 2022-12    
Investment Interest Rate [11],[27]   6.25%   6.25%    
Investment, Basis Spread, Variable Rate 3.30% [7] 3.30% [11],[27] 3.30% [7] 3.30% [11],[27]    
Investment, Interest Rate, Floor 8.05% [7] 8.05% [11],[27] 8.05% [7] 8.05% [11],[27]    
Interest Rate and Floor [11],[27]   6.25%   6.25%    
Principal Amount $ 11,451,000 [17],[29] $ 18,951,000 [27]        
Investment cost 12,677,000 [1],[17],[29] 20,036,000 [4],[27]        
Investments at Fair Value $ 12,780,000 [17],[29] $ 20,036,000 [27]        
Drug Discovery & Development | Senior Secured | Chemocentryx, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2025-02 2025-02 2025-02 2025-02    
Investment Interest Rate [11],[27]   7.15%   7.15%    
Investment, Basis Spread, Variable Rate 3.25% [7] 3.25% [11],[27] 3.25% [7] 3.25% [11],[27]    
Investment, Interest Rate, Floor 8.50% [7] 8.50% [11],[27] 8.50% [7] 8.50% [11],[27]    
Interest Rate and Floor [11],[27]   7.15%   7.15%    
Principal Amount $ 5,000,000 [17],[29] $ 5,000,000 [27]        
Investment cost 5,214,000 [1],[17],[29] 5,161,000 [2],[27]        
Investments at Fair Value $ 5,408,000 [17],[29] $ 5,070,000 [27]        
Drug Discovery & Development | Senior Secured | Nabriva Therapeutics | Debt Investments Under 1 Year Maturity            
Investment Holdings [Line Items]            
Maturity Date 2023-06   2023-06      
Investment, Basis Spread, Variable Rate [7] 4.30%   4.30%      
Investment, Interest Rate, Floor [7] 9.80%   9.80%      
Principal Amount [17],[29],[30] $ 3,077,000          
Investment cost [1],[17],[29],[30] 3,701,000          
Investments at Fair Value [17],[29],[30] $ 3,313,000          
Drug Discovery & Development | Senior Secured | Nabriva Therapeutics | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date   2023-06   2023-06    
Investment Interest Rate [11],[27],[28]   6.95%   6.95%    
Investment, Basis Spread, Variable Rate [11],[27],[28]   4.30%   4.30%    
Investment, Interest Rate, Floor [11],[27],[28]   9.80%   9.80%    
Interest Rate and Floor [11],[27],[28]   6.95%   6.95%    
Principal Amount [27],[28]   $ 5,000,000        
Investment cost [2],[27],[28]   5,500,000        
Investments at Fair Value [27],[28]   $ 5,459,000        
Drug Discovery & Development | Senior Secured | Akero Therapeutics, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2027-01   2027-01      
Investment, Basis Spread, Variable Rate [7] 3.65%   3.65%      
Investment, Interest Rate, Floor [7] 7.65%   7.65%      
Principal Amount [10],[29] $ 5,000,000          
Investment cost [1],[10],[29] 4,966,000          
Investments at Fair Value [10],[29] $ 4,983,000          
Drug Discovery & Development | Senior Secured | Albireo Pharma, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date   2024-07   2024-07    
Investment Interest Rate [11],[27]   6.95%   6.95%    
Investment, Basis Spread, Variable Rate [11],[27]   5.90%   5.90%    
Investment, Interest Rate, Floor [11],[27]   9.15%   9.15%    
Interest Rate and Floor [11],[27]   6.95%   6.95%    
Principal Amount [14],[27]   $ 10,000,000        
Investment cost [4],[14],[27]   10,229,000        
Investments at Fair Value [14],[27]   $ 10,268,000        
Drug Discovery & Development | Senior Secured | Alladapt Immunotherapeutics Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2026-09   2026-09      
Investment, Basis Spread, Variable Rate [7] 3.65%   3.65%      
Investment, Interest Rate, Floor [7] 8.40%   8.40%      
Principal Amount [10] $ 15,000,000          
Investment cost [1],[10] 14,858,000          
Investments at Fair Value [10] $ 14,858,000          
Drug Discovery & Development | Senior Secured | Aldeyra Therapeutics, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2023-10 2023-10 2023-10 2023-10    
Investment Interest Rate [11]   6.95%   6.95%    
Investment, Basis Spread, Variable Rate 3.10% [7] 3.10% [11] 3.10% [7] 3.10% [11]    
Investment, Interest Rate, Floor 8.60% [7] 8.60% [11] 8.60% [7] 8.60% [11]    
Interest Rate and Floor [11]   6.95%   6.95%    
Principal Amount $ 15,000,000 [12] $ 15,000,000        
Investment cost 15,817,000 [1],[12] 15,639,000 [4]        
Investments at Fair Value $ 15,608,000 [12] $ 15,653,000        
Drug Discovery & Development | Senior Secured | Applied Genetic Technologies Corporation | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2024-04 2024-04 2024-04 2024-04    
Investment Interest Rate [11]   9.75%   9.75%    
Investment, Basis Spread, Variable Rate 6.50% [7] 6.50% [11] 6.50% [7] 6.50% [11]    
Investment, Interest Rate, Floor [7] 9.75%   9.75%      
Interest Rate and Floor [11]   9.75%   9.75%    
Principal Amount $ 15,609,000 [17] $ 20,000,000        
Investment cost 16,450,000 [1],[17] 20,416,000 [4]        
Investments at Fair Value $ 16,308,000 [17] $ 20,339,000        
Drug Discovery & Development | Senior Secured | ATAI Life Sciences N.V. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2026-08   2026-08      
Investment, Basis Spread, Variable Rate [7] 4.55%   4.55%      
Investment, Interest Rate, Floor [7] 8.55%   8.55%      
Principal Amount [10],[29],[30] $ 10,500,000          
Investment cost [1],[10],[29],[30] 10,467,000          
Investments at Fair Value [10],[29],[30] $ 10,467,000          
Drug Discovery & Development | Senior Secured | Aveo Pharmaceuticals, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2024-09 2024-09 2024-09 2024-09    
Investment, Basis Spread, Variable Rate 6.40% [7] 6.40% [11] 6.40% [7] 6.40% [11]    
Investment, Interest Rate, Floor 9.65% [7] 9.65% [11] 9.65% [7] 9.65% [11]    
Principal Amount $ 40,000,000 [12],[31] $ 40,000,000 [14],[32]        
Investment cost 41,439,000 [1],[12],[31] 40,842,000 [4],[14],[32]        
Investments at Fair Value $ 41,374,000 [12],[31] $ 40,776,000 [14],[32]        
Drug Discovery & Development | Senior Secured | Axsome Therapeutics, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2026-10 2026-10 2026-10 2026-10    
Investment Interest Rate [11],[27]   5.82%   5.82%    
Investment, Basis Spread, Variable Rate 5.70% [7] 5.70% [11],[27] 5.70% [7] 5.70% [11],[27]    
Investment, Interest Rate, Floor 8.95% [7] 8.95% [11],[27] 8.95% [7] 8.95% [11],[27]    
Interest Rate and Floor [11],[27]   5.82%   5.82%    
Principal Amount $ 81,725,000 [10],[12],[18],[19],[29] $ 50,000,000 [27],[33]        
Investment cost 81,388,000 [1],[10],[12],[18],[19],[29] 49,542,000 [4],[27],[33]        
Investments at Fair Value $ 79,295,000 [10],[12],[18],[19],[29] $ 48,859,000 [27],[33]        
Drug Discovery & Development | Senior Secured | Bicycle Therapeutics PLC | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2025-07 2024-10 2025-07 2024-10    
Investment Interest Rate [11],[27],[28]   5.00%   5.00%    
Investment, Basis Spread, Variable Rate 4.55% [7] 5.60% [11],[27],[28] 4.55% [7] 5.60% [11],[27],[28]    
Investment, Interest Rate, Floor 8.05% [7] 8.85% [11],[27],[28] 8.05% [7] 8.85% [11],[27],[28]    
Interest Rate and Floor [11],[27],[28]   5.00%   5.00%    
Principal Amount $ 11,500,000 [12],[18],[29],[30] $ 24,000,000 [14],[15],[27],[28],[33]        
Investment cost 11,724,000 [1],[12],[18],[29],[30] 24,271,000 [4],[14],[15],[27],[28],[33]        
Investments at Fair Value $ 11,619,000 [12],[18],[29],[30] $ 24,454,000 [14],[15],[27],[28],[33]        
Drug Discovery & Development | Senior Secured | BiomX, INC | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2025-09 2025-09 2025-09 2025-09    
Investment, Basis Spread, Variable Rate 5.70% [7] 5.70% [11],[27],[28] 5.70% [7] 5.70% [11],[27],[28]    
Investment, Interest Rate, Floor 8.95% [7] 8.95% [11],[27],[28] 8.95% [7] 8.95% [11],[27],[28]    
Principal Amount $ 9,000,000 [12],[29],[30] $ 9,000,000 [14],[27],[28]        
Investment cost 9,125,000 [1],[12],[29],[30] 8,980,000 [4],[14],[27],[28]        
Investments at Fair Value $ 9,004,000 [12],[29],[30] $ 8,980,000 [14],[27],[28]        
Drug Discovery & Development | Senior Secured | BridgeBio Pharma, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2026-11 2026-11 2026-11 2026-11    
Investment, Interest Rate, Paid in Cash 9.00% [7] 9.00% [11] 9.00% [7] 9.00% [11]    
Investment Interest Rate [11]   2.00%   2.00%    
Interest Rate and Floor [11]   2.00%   2.00%    
Principal Amount $ 37,022,000 [9],[17],[18] $ 38,000,000        
Investment cost 36,694,000 [1],[9],[17],[18] 37,462,000 [4]        
Investments at Fair Value $ 33,561,000 [9],[17],[18] $ 37,462,000        
Drug Discovery & Development | Senior Secured | Cellarity, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2026-06 2026-06 2026-06 2026-06    
Investment Interest Rate [11]   3.75%   3.75%    
Investment, Basis Spread, Variable Rate 5.70% [7] 5.70% [11] 5.70% [7] 5.70% [11]    
Investment, Interest Rate, Floor 8.95% [7] 8.95% [11] 8.95% [7] 8.95% [11]    
Interest Rate and Floor [11]   3.75%   3.75%    
Principal Amount $ 30,000,000 [17],[31] $ 30,000,000 [32]        
Investment cost 29,734,000 [1],[17],[31] 29,422,000 [4],[32]        
Investments at Fair Value $ 29,943,000 [17],[31] $ 29,422,000 [32]        
Drug Discovery & Development | Senior Secured | Century Therapeutics, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2024-04 2024-04 2024-04 2024-04    
Investment Interest Rate [11]   3.95%   3.95%    
Investment, Basis Spread, Variable Rate 6.30% [7] 6.30% [11] 6.30% [7] 6.30% [11]    
Investment, Interest Rate, Floor 9.55% [7] 9.55% [11] 9.55% [7] 9.55% [11]    
Interest Rate and Floor [11]   3.95%   3.95%    
Principal Amount $ 10,000,000 [12] $ 10,000,000 [14]        
Investment cost 10,197,000 [1],[12] 10,075,000 [4],[14]        
Investments at Fair Value $ 10,261,000 [12] $ 10,361,000 [14]        
Drug Discovery & Development | Senior Secured | Codiak Biosciences, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2025-10 2025-10 2025-10 2025-10    
Investment Interest Rate [11]   5.50%   5.50%    
Investment, Basis Spread, Variable Rate 5.00% [7] 5.00% [11] 5.00% [7] 5.00% [11]    
Investment, Interest Rate, Floor 8.25% [7] 8.25% [11] 8.25% [7] 8.25% [11]    
Interest Rate and Floor [11]   5.50%   5.50%    
Principal Amount $ 25,000,000 [12] $ 25,000,000 [14]        
Investment cost 25,681,000 [1],[12] 25,459,000 [2],[14]        
Investments at Fair Value $ 25,076,000 [12] $ 25,316,000 [14]        
Drug Discovery & Development | Senior Secured | Corium, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2026-09 2026-09 2026-09 2026-09    
Investment Interest Rate [11]   7.75%   7.75%    
Investment, Basis Spread, Variable Rate 5.70% [7] 5.70% [11] 5.70% [7] 5.70% [11]    
Investment, Interest Rate, Floor 8.95% [7] 8.95% [11] 8.95% [7] 8.95% [11]    
Interest Rate and Floor [11]   7.75%   7.75%    
Principal Amount $ 132,675,000 [17],[19] $ 91,500,000 [21]        
Investment cost 133,069,000 [1],[17],[19] 90,997,000 [2],[21]        
Investments at Fair Value $ 135,828,000 [17],[19] $ 90,997,000 [21]        
Drug Discovery & Development | Senior Secured | Eloxx Pharmaceuticals, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2025-04 2025-04 2025-04 2025-04    
Investment Interest Rate [11]   6.25%   6.25%    
Investment, Basis Spread, Variable Rate [7] 6.25%   6.25%      
Investment, Interest Rate, Floor 9.50% [7] 9.50% [11] 9.50% [7] 9.50% [11]    
Interest Rate and Floor [11]   6.25%   6.25%    
Principal Amount $ 12,500,000 [31] $ 12,500,000 [32]        
Investment cost 12,673,000 [1],[31] 12,443,000 [2],[32]        
Investments at Fair Value $ 12,408,000 [31] $ 12,443,000 [32]        
Drug Discovery & Development | Senior Secured | enGene, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2025-07 2025-07 2025-07 2025-07    
Investment Interest Rate [11],[27],[28]   6.35%   6.35%    
Investment, Basis Spread, Variable Rate 5.00% [7] 5.00% [11],[27],[28] 5.00% [7] 5.00% [11],[27],[28]    
Investment, Interest Rate, Floor [11],[27],[28]   8.25%   8.25%    
Interest Rate and Floor [11],[27],[28]   6.35%   6.35%    
Principal Amount $ 11,000,000 [17],[29],[30] $ 7,000,000 [27],[28]        
Investment cost 10,994,000 [1],[17],[29],[30] 6,858,000 [2],[27],[28]        
Investments at Fair Value $ 10,918,000 [17],[29],[30] $ 6,858,000 [27],[28]        
Drug Discovery & Development | Senior Secured | Finch Therapeutics Group, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2026-11   2026-11      
Investment, Basis Spread, Variable Rate [7] 4.05%   4.05%      
Investment, Interest Rate, Floor [7] 7.55%   7.55%      
Principal Amount [10] $ 15,000,000          
Investment cost [1],[10] 14,958,000          
Investments at Fair Value [10] $ 14,241,000          
Drug Discovery & Development | Senior Secured | G1 Therapeutics, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2026-11 2026-11 2026-11 2026-11    
Investment Interest Rate [11],[27]   9.86%   9.86%    
Investment, Basis Spread, Variable Rate 5.90% [7] 5.90% [11],[27] 5.90% [7] 5.90% [11],[27]    
Investment, Interest Rate, Floor 9.15% [7] 9.15% [11],[27] 9.15% [7] 9.15% [11],[27]    
Interest Rate and Floor [11],[27]   9.86%   9.86%    
Principal Amount $ 58,125,000 [10],[12],[18],[31] $ 58,125,000 [14],[15],[27],[32],[33]        
Investment cost 58,472,000 [1],[10],[12],[18],[31] 57,873,000 [2],[14],[15],[27],[32],[33]        
Investments at Fair Value $ 58,006,000 [10],[12],[18],[31] $ 57,874,000 [14],[15],[27],[32],[33]        
Drug Discovery & Development | Senior Secured | Geron Corporation | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2024-10 2024-10 2024-10 2024-10    
Investment Interest Rate [11],[27]   6.55%   6.55%    
Investment, Basis Spread, Variable Rate 5.75% [7] 5.75% [11],[27] 5.75% [7] 5.75% [11],[27]    
Investment, Interest Rate, Floor 9.00% [7] 9.00% [11],[27] 9.00% [7] 9.00% [11],[27]    
Interest Rate and Floor [11],[27]   6.55%   6.55%    
Principal Amount $ 18,500,000 [17],[18],[29] $ 32,500,000 [27],[33]        
Investment cost 19,003,000 [1],[17],[18],[29] 32,704,000 [2],[27],[33]        
Investments at Fair Value $ 19,059,000 [17],[18],[29] $ 32,744,000 [27],[33]        
Drug Discovery & Development | Senior Secured | Gritstone Bio, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2027-07   2027-07      
Investment, Basis Spread, Variable Rate [7] 3.15%   3.15%      
Investment, Interest Rate, Floor [7] 7.15%   7.15%      
Investment, Interest Rate, Paid in Kind [7] 2.00%   2.00%      
Principal Amount [9],[10] $ 15,037,000          
Investment cost [1],[9],[10] 14,989,000          
Investments at Fair Value [9],[10] $ 14,989,000          
Drug Discovery & Development | Senior Secured | Hibercell, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2025-05 2025-05 2025-05 2025-05    
Investment Interest Rate [11]   4.95%   4.95%    
Investment, Basis Spread, Variable Rate 5.40% [7] 5.40% [11] 5.40% [7] 5.40% [11]    
Investment, Interest Rate, Floor 8.65% [7] 8.65% [11] 8.65% [7] 8.65% [11]    
Interest Rate and Floor [11]   4.95%   4.95%    
Principal Amount $ 17,000,000 [17],[31] $ 17,000,000 [32]        
Investment cost 17,244,000 [1],[17],[31] 17,041,000 [2],[32]        
Investments at Fair Value $ 17,225,000 [17],[31] $ 17,014,000 [32]        
Drug Discovery & Development | Senior Secured | HilleVax, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2027-05   2027-05      
Investment, Basis Spread, Variable Rate [7] 1.05%   1.05%      
Investment, Interest Rate, Floor [7] 4.55%   4.55%      
Investment, Interest Rate, Paid in Kind [7] 2.85%   2.85%      
Principal Amount [9],[10],[31] $ 4,043,000          
Investment cost [1],[9],[10],[31] 4,043,000          
Investments at Fair Value [9],[10],[31] $ 4,044,000          
Drug Discovery & Development | Senior Secured | Iveric Bio Gene Therapy LLC | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2027-08   2027-08      
Investment, Basis Spread, Variable Rate [7] 4.00%   4.00%      
Investment, Interest Rate, Floor [7] 8.75%   8.75%      
Principal Amount [10],[29] $ 24,750,000          
Investment cost [1],[10],[29] 24,530,000          
Investments at Fair Value [10],[29] $ 24,531,000          
Drug Discovery & Development | Senior Secured | Humanigen, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date   2025-03   2025-03    
Investment Interest Rate [11],[26],[27]   6.75%   6.75%    
Investment, Basis Spread, Variable Rate [11],[26],[27]   5.50%   5.50%    
Investment, Interest Rate, Floor [11],[26],[27]   8.75%   8.75%    
Interest Rate and Floor [11],[26],[27]   6.75%   6.75%    
Principal Amount [26],[27]   $ 20,000,000        
Investment cost [2],[26],[27]   20,235,000        
Investments at Fair Value [26],[27]   $ 19,985,000        
Drug Discovery & Development | Senior Secured | Kaleido Biosciences, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date   2024-01   2024-01    
Investment Interest Rate [11]   7.55%   7.55%    
Investment, Basis Spread, Variable Rate [11]   6.10%   6.10%    
Investment, Interest Rate, Floor [11]   9.35%   9.35%    
Interest Rate and Floor [11]   7.55%   7.55%    
Principal Amount [33]   $ 22,500,000        
Investment cost [2],[33]   23,505,000        
Investments at Fair Value [33]   $ 23,384,000        
Drug Discovery & Development | Senior Secured | Locus Biosciences, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2025-07 2025-07 2025-07 2025-07    
Investment Interest Rate [11]   4.95%   4.95%    
Investment, Basis Spread, Variable Rate 6.10% [7] 6.10% [11] 6.10% [7] 6.10% [11]    
Investment, Interest Rate, Floor 9.35% [7] 9.35% [11] 9.35% [7] 9.35% [11]    
Interest Rate and Floor [11]   4.95%   4.95%    
Principal Amount $ 8,000,000 [31] $ 8,000,000 [32]        
Investment cost 8,084,000 [1],[31] 7,977,000 [2],[32]        
Investments at Fair Value $ 8,062,000 [31] $ 7,900,000 [32]        
Drug Discovery & Development | Senior Secured | Madrigal Pharmaceutical, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2026-05   2026-05      
Investment, Basis Spread, Variable Rate [7] 3.95%   3.95%      
Investment, Interest Rate, Floor [7] 7.45%   7.45%      
Principal Amount [29] $ 34,000,000          
Investment cost [1],[29] 33,807,000          
Investments at Fair Value [29] $ 33,807,000          
Drug Discovery & Development | Senior Secured | Phathom Pharmaceuticals, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2026-10 2026-10 2026-10 2026-10    
Investment Interest Rate [11],[27]   7.50%   7.50%    
Investment, Basis Spread, Variable Rate 2.25% [7] 2.25% [11],[27] 2.25% [7] 2.25% [11],[27]    
Investment, Interest Rate, Floor 5.50% [7] 5.50% [11],[27] 5.50% [7] 5.50% [11],[27]    
Investment, Interest Rate, Paid in Kind 3.35% [7] 3.35% [11],[27] 3.35% [7] 3.35% [11],[27]    
Interest Rate and Floor [11],[27]   7.50%   7.50%    
Principal Amount $ 93,978,000 [9],[10],[18],[19],[29],[31] $ 87,116,000 [15],[20],[21],[27],[32],[33]        
Investment cost 93,948,000 [1],[9],[10],[18],[19],[29],[31] 86,075,000 [2],[15],[20],[21],[27],[32],[33]        
Investments at Fair Value $ 94,006,000 [9],[10],[18],[19],[29],[31] $ 86,075,000 [15],[20],[21],[27],[32],[33]        
Drug Discovery & Development | Senior Secured | Provention Bio, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2026-09   2026-09      
Investment, Basis Spread, Variable Rate [7] 2.70%   2.70%      
Investment, Interest Rate, Floor [7] 8.20%   8.20%      
Principal Amount $ 25,000,000          
Investment cost [1] 24,552,000          
Investments at Fair Value $ 24,552,000          
Drug Discovery & Development | Senior Secured | Redshift Bioanalytics, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2026-01   2026-01      
Investment, Basis Spread, Variable Rate [7] 4.25%   4.25%      
Investment, Interest Rate, Floor [7] 7.50%   7.50%      
Principal Amount [31] $ 5,000,000          
Investment cost [1],[31] 4,936,000          
Investments at Fair Value [31] $ 4,935,000          
Drug Discovery & Development | Senior Secured | Scynexis, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2025-03 2025-03 2025-03 2025-03    
Investment Interest Rate [11]   3.95%   3.95%    
Investment, Basis Spread, Variable Rate 5.80% [7] 5.80% [11] 5.80% [7] 5.80% [11]    
Investment, Interest Rate, Floor 9.05% [7] 9.05% [11] 9.05% [7] 9.05% [11]    
Interest Rate and Floor [11]   3.95%   3.95%    
Principal Amount $ 18,667,000 [17],[18] $ 16,000,000        
Investment cost 18,592,000 [1],[17],[18] 15,826,000 [2]        
Investments at Fair Value $ 18,524,000 [17],[18] $ 15,778,000        
Drug Discovery & Development | Senior Secured | Seres Therapeutics, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2024-10 2023-11 2024-10 2023-11    
Investment Interest Rate [11]   4.85%   4.85%    
Investment, Basis Spread, Variable Rate 6.40% [7] 4.40% [11] 6.40% [7] 4.40% [11]    
Investment, Interest Rate, Floor 9.65% [7] 9.65% [11] 9.65% [7] 9.65% [11]    
Interest Rate and Floor [11]   4.85%   4.85%    
Principal Amount $ 37,500,000 [17],[18] $ 24,051,000        
Investment cost 38,509,000 [1],[17],[18] 24,777,000 [2]        
Investments at Fair Value $ 38,657,000 [17],[18] $ 25,183,000        
Drug Discovery & Development | Senior Secured | Syndax Pharmaceutics Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date   2024-04   2024-04    
Investment Interest Rate [11]   4.99%   4.99%    
Investment, Basis Spread, Variable Rate [11]   6.00%   6.00%    
Investment, Interest Rate, Floor [11]   9.25%   9.25%    
Interest Rate and Floor [11]   4.99%   4.99%    
Principal Amount [15],[33]   $ 20,000,000        
Investment cost [2],[15],[33]   20,646,000        
Investments at Fair Value [15],[33]   $ 20,653,000        
Drug Discovery & Development | Senior Secured | Tarsus Pharmaceuticals, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2027-02   2027-02      
Investment, Basis Spread, Variable Rate [7] 5.20%   5.20%      
Investment, Interest Rate, Floor [7] 8.45%   8.45%      
Principal Amount [10],[17],[29] $ 8,250,000          
Investment cost [1],[10],[17],[29] 8,255,000          
Investments at Fair Value [10],[17],[29] $ 8,388,000          
Drug Discovery & Development | Senior Secured | TG Therapeutics, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2026-01 2026-01 2026-01 2026-01    
Investment Interest Rate [11],[27]   5.95%   5.95%    
Investment, Basis Spread, Variable Rate 2.15% [7] 2.15% [11],[27] 2.15% [7] 2.15% [11],[27]    
Investment, Interest Rate, Floor 5.40% [7] 5.40% [11],[27] 5.40% [7] 5.40% [11],[27]    
Investment, Interest Rate, Paid in Kind [7] 3.45%   3.45%      
Interest Rate and Floor [11],[27]   5.95%   5.95%    
Principal Amount $ 47,567,000 [9],[12],[18],[29] $ 51,450,000 [27]        
Investment cost 47,267,000 [1],[9],[12],[18],[29] 50,470,000 [2],[27]        
Investments at Fair Value $ 47,137,000 [9],[12],[18],[29] $ 50,470,000 [27]        
Drug Discovery & Development | Senior Secured | Uni Qure B V | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2025-12 2025-12 2025-12 2025-12    
Investment Interest Rate [11],[27],[28]   7.28%   7.28%    
Investment, Basis Spread, Variable Rate 4.70% [7] 4.70% [11],[27],[28] 4.70% [7] 4.70% [11],[27],[28]    
Investment, Interest Rate, Floor 7.95% [7] 7.95% [11],[27],[28] 7.95% [7] 7.95% [11],[27],[28]    
Interest Rate and Floor [11],[27],[28]   7.28%   7.28%    
Principal Amount $ 70,000,000 [12],[18],[19],[29],[30] $ 77,500,000 [14],[21],[27],[28],[33]        
Investment cost 72,015,000 [1],[12],[18],[19],[29],[30] 78,755,000 [2],[14],[21],[27],[28],[33]        
Investments at Fair Value $ 73,205,000 [12],[18],[19],[29],[30] $ 78,755,000 [14],[21],[27],[28],[33]        
Drug Discovery & Development | Senior Secured | Unity Biotechnology Inc | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2024-08 2024-08 2024-08 2024-08    
Investment Interest Rate [11],[26]   6.25%   6.25%    
Investment, Basis Spread, Variable Rate 6.10% [7] 6.10% [11],[26] 6.10% [7] 6.10% [11],[26]    
Investment, Interest Rate, Floor 9.35% [7] 9.35% [11],[26] 9.35% [7] 9.35% [11],[26]    
Interest Rate and Floor [11],[26]   6.25%   6.25%    
Principal Amount $ 20,000,000 [17] $ 22,701,000 [26]        
Investment cost 20,990,000 [1],[17] 23,293,000 [2],[26]        
Investments at Fair Value $ 20,844,000 [17] $ 23,627,000 [26]        
Drug Discovery & Development | Senior Secured | Valo Health L L C | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2024-05 2024-05 2024-05 2024-05    
Investment Interest Rate [11]   3.85%   3.85%    
Investment, Basis Spread, Variable Rate 6.45% [7] 6.45% [11] 6.45% [7] 6.45% [11]    
Investment, Interest Rate, Floor 9.70% [7] 9.70% [11] 9.70% [7] 9.70% [11]    
Interest Rate and Floor [11]   3.85%   3.85%    
Principal Amount $ 9,583,000 [12],[17] $ 11,500,000 [14]        
Investment cost 9,805,000 [1],[12],[17] 11,547,000 [2],[14]        
Investments at Fair Value $ 9,760,000 [12],[17] $ 11,492,000 [14]        
Drug Discovery & Development | Senior Secured | Viridian Therapeutics Inc | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2026-10   2026-10      
Investment, Basis Spread, Variable Rate [7] 4.20%   4.20%      
Investment, Interest Rate, Floor [7] 7.45%   7.45%      
Principal Amount [10],[17],[29] $ 2,000,000          
Investment cost [1],[10],[17],[29] 2,004,000          
Investments at Fair Value [10],[17],[29] $ 1,969,000          
Drug Discovery & Development | Senior Secured | X Four Pharmaceuticals Inc | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date 2024-07 2024-07 2024-07 2024-07    
Investment Interest Rate [11]   8.80%   8.80%    
Investment, Basis Spread, Variable Rate 3.75% [7] 3.75% [11] 3.75% [7] 3.75% [11]    
Investment, Interest Rate, Floor 8.75% [7] 8.75% [11] 8.75% [7] 8.75% [11]    
Interest Rate and Floor [11]   8.80%   8.80%    
Principal Amount $ 32,500,000 [12],[17],[18] $ 32,500,000 [14],[33]        
Investment cost 33,464,000 [1],[12],[17],[18] 34,140,000 [2],[14],[33]        
Investments at Fair Value $ 33,291,000 [12],[17],[18] $ 34,085,000 [14],[33]        
Drug Discovery & Development | Senior Secured | Yumanity Therapeutics, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date   2024-01   2024-01    
Investment Interest Rate [11]   5.92%   5.92%    
Investment, Basis Spread, Variable Rate [11]   4.00%   4.00%    
Investment, Interest Rate, Floor [11]   8.75%   8.75%    
Interest Rate and Floor [11]   5.92%   5.92%    
Principal Amount   $ 12,732,000        
Investment cost [2]   13,256,000        
Investments at Fair Value   $ 13,187,000        
Drug Discovery & Development | Senior Secured | Center for Breakthrough Medicines Holdings, LLC [Member] | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Maturity Date   2023-05   2023-05    
Investment Interest Rate [11]   7.50%   7.50%    
Investment, Basis Spread, Variable Rate [11]   5.50%   5.50%    
Investment, Interest Rate, Floor [11]   8.75%   8.75%    
Interest Rate and Floor [11]   7.50%   7.50%    
Principal Amount   $ 5,000,000        
Investment cost [4]   5,005,000        
Investments at Fair Value   $ 5,005,000        
Drug Discovery & Development | Senior Secured | Floor Rate | enGene, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Investment, Interest Rate, Floor [7] 8.25%   8.25%      
Drug Discovery & Development | Senior Secured | Exit Fee | Chemocentryx, Inc. | Debt Investments Under 1 Year Maturity            
Investment Holdings [Line Items]            
Investment Interest Rate [7] 6.25%   6.25%      
Interest Rate and Floor [7] 6.25%   6.25%      
Drug Discovery & Development | Senior Secured | Exit Fee | Chemocentryx, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Investment Interest Rate [7] 7.15%   7.15%      
Interest Rate and Floor [7] 7.15%   7.15%      
Drug Discovery & Development | Senior Secured | Exit Fee | Nabriva Therapeutics | Debt Investments Under 1 Year Maturity            
Investment Holdings [Line Items]            
Investment Interest Rate [7] 9.95%   9.95%      
Interest Rate and Floor [7] 9.95%   9.95%      
Drug Discovery & Development | Senior Secured | Exit Fee | Akero Therapeutics, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Investment Interest Rate [7] 5.85%   5.85%      
Interest Rate and Floor [7] 5.85%   5.85%      
Drug Discovery & Development | Senior Secured | Exit Fee | Alladapt Immunotherapeutics Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Investment Interest Rate [7] 5.30%   5.30%      
Interest Rate and Floor [7] 5.30%   5.30%      
Drug Discovery & Development | Senior Secured | Exit Fee | Aldeyra Therapeutics, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Investment Interest Rate [7] 6.95%   6.95%      
Interest Rate and Floor [7] 6.95%   6.95%      
Drug Discovery & Development | Senior Secured | Exit Fee | Applied Genetic Technologies Corporation | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Investment Interest Rate 6.95% [7] 6.95% [11] 6.95% [7] 6.95% [11]    
Interest Rate and Floor 6.95% [7] 6.95% [11] 6.95% [7] 6.95% [11]    
Drug Discovery & Development | Senior Secured | Exit Fee | ATAI Life Sciences N.V. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Investment Interest Rate [7] 6.95%   6.95%      
Interest Rate and Floor [7] 6.95%   6.95%      
Drug Discovery & Development | Senior Secured | Exit Fee | Aveo Pharmaceuticals, Inc. | Debt Investments 1-5 Years Maturity            
Investment Holdings [Line Items]            
Investment Interest Rate 6.95% [7] 6.95% [11] 6.95% [7] 6.95% [11]