v3.26.1
Investment Portfolio - Schedule of Investment Portfolio, at Fair Value and Percentage (Details) - USD ($)
$ in Millions
3 Months Ended 12 Months Ended
Mar. 31, 2026
Dec. 31, 2025
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Fair Value $ 12,269.4 [1],[2] $ 13,008.6 [3],[4]
Percentage of Portfolio | Industry Concentration Risk    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Percentage of Portfolio 100.00% 100.00%
Capital Goods    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Fair Value $ 1,455.0 $ 1,542.0
Capital Goods | Percentage of Portfolio | Industry Concentration Risk    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Percentage of Portfolio 11.90% 11.90%
Commercial & Professional Services    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Fair Value $ 1,563.0 $ 1,726.0
Commercial & Professional Services | Percentage of Portfolio | Industry Concentration Risk    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Percentage of Portfolio 12.70% 13.30%
Consumer Discretionary Distribution & Retail    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Fair Value $ 54.0 $ 60.0
Consumer Discretionary Distribution & Retail | Percentage of Portfolio | Industry Concentration Risk    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Percentage of Portfolio 0.40% 0.50%
Consumer Durables & Apparel    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Fair Value $ 315.0 $ 306.0
Consumer Durables & Apparel | Percentage of Portfolio | Industry Concentration Risk    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Percentage of Portfolio 2.60% 2.40%
Consumer Services    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Fair Value $ 269.0 $ 263.0
Consumer Services | Percentage of Portfolio | Industry Concentration Risk    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Percentage of Portfolio 2.20% 2.00%
Consumer Staples Distribution & Retail    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Fair Value $ 102.0 $ 99.0
Consumer Staples Distribution & Retail | Percentage of Portfolio | Industry Concentration Risk    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Percentage of Portfolio 0.80% 0.80%
Credit Opportunities Partners JV, LLC    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Fair Value $ 1,707.0 $ 1,968.0
Credit Opportunities Partners JV, LLC | Percentage of Portfolio | Industry Concentration Risk    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Percentage of Portfolio 13.90% 15.10%
Energy    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Fair Value $ 2.0 $ 24.0
Energy | Percentage of Portfolio | Industry Concentration Risk    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Percentage of Portfolio 0.00% 0.20%
Equity Real Estate Investment Trusts (REITs)    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Fair Value $ 251.0 $ 264.0
Equity Real Estate Investment Trusts (REITs) | Percentage of Portfolio | Industry Concentration Risk    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Percentage of Portfolio 2.00% 2.00%
Financial Services    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Fair Value $ 819.0 $ 836.0
Financial Services | Percentage of Portfolio | Industry Concentration Risk    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Percentage of Portfolio 6.70% 6.40%
Food, Beverage & Tobacco    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Fair Value $ 55.0 $ 56.0
Food, Beverage & Tobacco | Percentage of Portfolio | Industry Concentration Risk    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Percentage of Portfolio 0.40% 0.40%
Health Care Equipment & Services    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Fair Value $ 1,572.0 $ 1,668.0
Health Care Equipment & Services | Percentage of Portfolio | Industry Concentration Risk    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Percentage of Portfolio 12.80% 12.80%
Household & Personal Products    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Fair Value $ 111.0 $ 112.0
Household & Personal Products | Percentage of Portfolio | Industry Concentration Risk    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Percentage of Portfolio 0.90% 0.90%
Insurance    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Fair Value $ 548.0 $ 547.0
Insurance | Percentage of Portfolio | Industry Concentration Risk    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Percentage of Portfolio 4.50% 4.20%
Materials    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Fair Value $ 321.0 $ 276.0
Materials | Percentage of Portfolio | Industry Concentration Risk    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Percentage of Portfolio 2.60% 2.10%
Media & Entertainment    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Fair Value $ 462.0 $ 508.0
Media & Entertainment | Percentage of Portfolio | Industry Concentration Risk    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Percentage of Portfolio 3.80% 3.90%
Pharmaceuticals, Biotechnology & Life Sciences    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Fair Value $ 253.0 $ 217.0
Pharmaceuticals, Biotechnology & Life Sciences | Percentage of Portfolio | Industry Concentration Risk    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Percentage of Portfolio 2.10% 1.70%
Real Estate Management & Development    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Fair Value $ 0.0 $ 1.0
Real Estate Management & Development | Percentage of Portfolio | Industry Concentration Risk    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Percentage of Portfolio 0.00% 0.00%
Software & Services    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Fair Value $ 2,010.0 $ 2,134.0
Software & Services | Percentage of Portfolio | Industry Concentration Risk    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Percentage of Portfolio 16.40% 16.40%
Technology Hardware & Equipment    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Fair Value $ 2.0 $ 2.0
Technology Hardware & Equipment | Percentage of Portfolio | Industry Concentration Risk    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Percentage of Portfolio 0.00% 0.00%
Telecommunication Services    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Fair Value $ 104.0 $ 109.0
Telecommunication Services | Percentage of Portfolio | Industry Concentration Risk    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Percentage of Portfolio 0.90% 0.80%
Transportation    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Fair Value $ 294.0 $ 291.0
Transportation | Percentage of Portfolio | Industry Concentration Risk    
Investment Company, Nonconsolidated Subsidiary [Line Items]    
Percentage of Portfolio 2.40% 2.20%
[1] Security may be an obligation of one or more entities affiliated with the named company.
[2] See Note 8 for additional information regarding the fair value of the Company’s financial instruments.
[3] Security may be an obligation of one or more entities affiliated with the named company.
[4] See Note 8 for additional information regarding the fair value of the Company’s financial instruments.