Quarterly report pursuant to Section 13 or 15(d)

Investments - Schedule of Fair Value Portfolio By Industry Sector (Details)

v3.23.1
Investments - Schedule of Fair Value Portfolio By Industry Sector (Details) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Mar. 31, 2023
Dec. 31, 2022
Schedule Of Investments [Line Items]    
Investments at Fair Value $ 3,130,178 $ 2,963,955
Drug Discovery & Development    
Schedule Of Investments [Line Items]    
Investments at Fair Value 1,220,057 1,150,707
Consumer & Business Products    
Schedule Of Investments [Line Items]    
Investments at Fair Value 2,593 2,821
Software    
Schedule Of Investments [Line Items]    
Investments at Fair Value 828,712 798,264
Consumer & Business Services    
Schedule Of Investments [Line Items]    
Investments at Fair Value 474,883 439,384
Communications & Networking    
Schedule Of Investments [Line Items]    
Investments at Fair Value 107,201 101,833
Healthcare Services Other    
Schedule Of Investments [Line Items]    
Investments at Fair Value 214,199 198,763
Information Services    
Schedule Of Investments [Line Items]    
Investments at Fair Value 62,039 60,759
Diversified Financial Services    
Schedule Of Investments [Line Items]    
Investments at Fair Value 87,805 68,569
Manufacturing Technology    
Schedule Of Investments [Line Items]    
Investments at Fair Value 48,993 46,109
Biotechnology Tools [Member]    
Schedule Of Investments [Line Items]    
Investments at Fair Value 33,032 32,825
Media Content Info [Member]    
Schedule Of Investments [Line Items]    
Investments at Fair Value 9,956 35
Drug Delivery    
Schedule Of Investments [Line Items]    
Investments at Fair Value 23 90
Medical Devices & Equipment    
Schedule Of Investments [Line Items]    
Investments at Fair Value 1,155 1,834
Surgical Devices    
Schedule Of Investments [Line Items]    
Investments at Fair Value 4,189 3,038
Electronics & Computer Hardware    
Schedule Of Investments [Line Items]    
Investments at Fair Value 21,476 21,517
Semiconductors    
Schedule Of Investments [Line Items]    
Investments at Fair Value 966 21,921
Sustainable And Renewable Technology    
Schedule Of Investments [Line Items]    
Investments at Fair Value $ 12,899 $ 15,486
Industry Sub Sector Concentration Risk [Member] | Revenue Benchmark    
Schedule Of Investments [Line Items]    
Concentration Risk, Percentage 100.00% 100.00%
Industry Sub Sector Concentration Risk [Member] | Revenue Benchmark | Drug Discovery & Development    
Schedule Of Investments [Line Items]    
Concentration Risk, Percentage 39.00% 38.80%
Industry Sub Sector Concentration Risk [Member] | Revenue Benchmark | Consumer & Business Products    
Schedule Of Investments [Line Items]    
Concentration Risk, Percentage 0.10% 0.10%
Industry Sub Sector Concentration Risk [Member] | Revenue Benchmark | Software    
Schedule Of Investments [Line Items]    
Concentration Risk, Percentage 26.50% 26.90%
Industry Sub Sector Concentration Risk [Member] | Revenue Benchmark | Consumer & Business Services    
Schedule Of Investments [Line Items]    
Concentration Risk, Percentage 15.20% 14.80%
Industry Sub Sector Concentration Risk [Member] | Revenue Benchmark | Communications & Networking    
Schedule Of Investments [Line Items]    
Concentration Risk, Percentage 3.40% 3.50%
Industry Sub Sector Concentration Risk [Member] | Revenue Benchmark | Healthcare Services Other    
Schedule Of Investments [Line Items]    
Concentration Risk, Percentage 6.80% 6.70%
Industry Sub Sector Concentration Risk [Member] | Revenue Benchmark | Information Services    
Schedule Of Investments [Line Items]    
Concentration Risk, Percentage 2.00% 2.10%
Industry Sub Sector Concentration Risk [Member] | Revenue Benchmark | Diversified Financial Services    
Schedule Of Investments [Line Items]    
Concentration Risk, Percentage 2.80% 2.30%
Industry Sub Sector Concentration Risk [Member] | Revenue Benchmark | Manufacturing Technology    
Schedule Of Investments [Line Items]    
Concentration Risk, Percentage 1.60% 1.60%
Industry Sub Sector Concentration Risk [Member] | Revenue Benchmark | Biotechnology Tools [Member]    
Schedule Of Investments [Line Items]    
Concentration Risk, Percentage 1.10% 1.10%
Industry Sub Sector Concentration Risk [Member] | Revenue Benchmark | Media Content Info [Member]    
Schedule Of Investments [Line Items]    
Concentration Risk, Percentage 0.30% 0.00%
Industry Sub Sector Concentration Risk [Member] | Revenue Benchmark | Drug Delivery    
Schedule Of Investments [Line Items]    
Concentration Risk, Percentage 0.00% 0.00%
Industry Sub Sector Concentration Risk [Member] | Revenue Benchmark | Medical Devices & Equipment    
Schedule Of Investments [Line Items]    
Concentration Risk, Percentage 0.00% 0.10%
Industry Sub Sector Concentration Risk [Member] | Revenue Benchmark | Surgical Devices    
Schedule Of Investments [Line Items]    
Concentration Risk, Percentage 0.10% 0.10%
Industry Sub Sector Concentration Risk [Member] | Revenue Benchmark | Electronics & Computer Hardware    
Schedule Of Investments [Line Items]    
Concentration Risk, Percentage 0.70% 0.70%
Industry Sub Sector Concentration Risk [Member] | Revenue Benchmark | Semiconductors    
Schedule Of Investments [Line Items]    
Concentration Risk, Percentage 0.00% 0.70%
Industry Sub Sector Concentration Risk [Member] | Revenue Benchmark | Sustainable And Renewable Technology    
Schedule Of Investments [Line Items]    
Concentration Risk, Percentage 0.40% 0.50%