Quarterly report [Sections 13 or 15(d)]

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

v3.26.1
Investments - Schedule of Fair Value Portfolio by Industry Sector (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Mar. 31, 2026
Dec. 31, 2025
Schedule Of Investments [Line Items]    
Investments at Fair Value $ 4,721,987 $ 4,466,647
Industry Sub Sector Concentration Risk | Total Industry Sectors    
Schedule Of Investments [Line Items]    
Investments at Fair Value 4,721,987 4,466,647
Industry Sub Sector Concentration Risk | Application Software    
Schedule Of Investments [Line Items]    
Investments at Fair Value 1,113,788 1,087,954
Industry Sub Sector Concentration Risk | Drug Discovery & Development    
Schedule Of Investments [Line Items]    
Investments at Fair Value 1,089,920 1,039,712
Industry Sub Sector Concentration Risk | Healthcare Services, Other    
Schedule Of Investments [Line Items]    
Investments at Fair Value 890,720 838,508
Industry Sub Sector Concentration Risk | System Software    
Schedule Of Investments [Line Items]    
Investments at Fair Value 507,172 472,144
Industry Sub Sector Concentration Risk | Consumer & Business Services    
Schedule Of Investments [Line Items]    
Investments at Fair Value 474,202 449,631
Industry Sub Sector Concentration Risk | Defense Technologies    
Schedule Of Investments [Line Items]    
Investments at Fair Value 157,631 140,458
Industry Sub Sector Concentration Risk | Diversified Financial Services    
Schedule Of Investments [Line Items]    
Investments at Fair Value 106,304 105,896
Industry Sub Sector Concentration Risk | Medical Devices & Equipment    
Schedule Of Investments [Line Items]    
Investments at Fair Value 81,619 77,257
Industry Sub Sector Concentration Risk | Electronics & Computer Hardware    
Schedule Of Investments [Line Items]    
Investments at Fair Value 66,735 66,992
Industry Sub Sector Concentration Risk | Space Technologies    
Schedule Of Investments [Line Items]    
Investments at Fair Value 53,167 47,816
Industry Sub Sector Concentration Risk | Consumer & Business Products    
Schedule Of Investments [Line Items]    
Investments at Fair Value 42,187 8,810
Industry Sub Sector Concentration Risk | Sustainable and Renewable Technology    
Schedule Of Investments [Line Items]    
Investments at Fair Value 35,804 35,759
Industry Sub Sector Concentration Risk | Communications & Networking    
Schedule Of Investments [Line Items]    
Investments at Fair Value 32,063 26,263
Industry Sub Sector Concentration Risk | Information Services    
Schedule Of Investments [Line Items]    
Investments at Fair Value 25,634 25,889
Industry Sub Sector Concentration Risk | Biotechnology Tools    
Schedule Of Investments [Line Items]    
Investments at Fair Value 24,060 23,164
Industry Sub Sector Concentration Risk | Manufacturing Technology    
Schedule Of Investments [Line Items]    
Investments at Fair Value 20,753 20,190
Industry Sub Sector Concentration Risk | Semiconductors    
Schedule Of Investments [Line Items]    
Investments at Fair Value 187 158
Industry Sub Sector Concentration Risk | Media/Content/Info    
Schedule Of Investments [Line Items]    
Investments at Fair Value 31 32
Industry Sub Sector Concentration Risk | Drug Delivery    
Schedule Of Investments [Line Items]    
Investments at Fair Value $ 10 $ 14
Industry Sub Sector Concentration Risk | Industry Sub Sector Investments Benchmark | Total Industry Sectors    
Schedule Of Investments [Line Items]    
Percentage of Total Portfolio 100.00% 100.00%
Industry Sub Sector Concentration Risk | Industry Sub Sector Investments Benchmark | Application Software    
Schedule Of Investments [Line Items]    
Percentage of Total Portfolio 23.60% 24.30%
Industry Sub Sector Concentration Risk | Industry Sub Sector Investments Benchmark | Drug Discovery & Development    
Schedule Of Investments [Line Items]    
Percentage of Total Portfolio 23.10% 23.30%
Industry Sub Sector Concentration Risk | Industry Sub Sector Investments Benchmark | Healthcare Services, Other    
Schedule Of Investments [Line Items]    
Percentage of Total Portfolio 18.90% 18.80%
Industry Sub Sector Concentration Risk | Industry Sub Sector Investments Benchmark | System Software    
Schedule Of Investments [Line Items]    
Percentage of Total Portfolio 10.70% 10.60%
Industry Sub Sector Concentration Risk | Industry Sub Sector Investments Benchmark | Consumer & Business Services    
Schedule Of Investments [Line Items]    
Percentage of Total Portfolio 10.00% 10.10%
Industry Sub Sector Concentration Risk | Industry Sub Sector Investments Benchmark | Defense Technologies    
Schedule Of Investments [Line Items]    
Percentage of Total Portfolio 3.30% 3.10%
Industry Sub Sector Concentration Risk | Industry Sub Sector Investments Benchmark | Diversified Financial Services    
Schedule Of Investments [Line Items]    
Percentage of Total Portfolio 2.30% 2.40%
Industry Sub Sector Concentration Risk | Industry Sub Sector Investments Benchmark | Medical Devices & Equipment    
Schedule Of Investments [Line Items]    
Percentage of Total Portfolio 1.70% 1.70%
Industry Sub Sector Concentration Risk | Industry Sub Sector Investments Benchmark | Electronics & Computer Hardware    
Schedule Of Investments [Line Items]    
Percentage of Total Portfolio 1.40% 1.50%
Industry Sub Sector Concentration Risk | Industry Sub Sector Investments Benchmark | Space Technologies    
Schedule Of Investments [Line Items]    
Percentage of Total Portfolio 1.10% 1.10%
Industry Sub Sector Concentration Risk | Industry Sub Sector Investments Benchmark | Consumer & Business Products    
Schedule Of Investments [Line Items]    
Percentage of Total Portfolio 0.90% 0.20%
Industry Sub Sector Concentration Risk | Industry Sub Sector Investments Benchmark | Sustainable and Renewable Technology    
Schedule Of Investments [Line Items]    
Percentage of Total Portfolio 0.80% 0.80%
Industry Sub Sector Concentration Risk | Industry Sub Sector Investments Benchmark | Communications & Networking    
Schedule Of Investments [Line Items]    
Percentage of Total Portfolio 0.70% 0.60%
Industry Sub Sector Concentration Risk | Industry Sub Sector Investments Benchmark | Information Services    
Schedule Of Investments [Line Items]    
Percentage of Total Portfolio 0.60% 0.60%
Industry Sub Sector Concentration Risk | Industry Sub Sector Investments Benchmark | Biotechnology Tools    
Schedule Of Investments [Line Items]    
Percentage of Total Portfolio 0.50% 0.50%
Industry Sub Sector Concentration Risk | Industry Sub Sector Investments Benchmark | Manufacturing Technology    
Schedule Of Investments [Line Items]    
Percentage of Total Portfolio 0.40% 0.40%
Industry Sub Sector Concentration Risk | Industry Sub Sector Investments Benchmark | Semiconductors    
Schedule Of Investments [Line Items]    
Percentage of Total Portfolio 0.00% 0.00%
Industry Sub Sector Concentration Risk | Industry Sub Sector Investments Benchmark | Media/Content/Info    
Schedule Of Investments [Line Items]    
Percentage of Total Portfolio 0.00% 0.00%
Industry Sub Sector Concentration Risk | Industry Sub Sector Investments Benchmark | Drug Delivery    
Schedule Of Investments [Line Items]    
Percentage of Total Portfolio 0.00% 0.00%