v3.25.2
INVESTMENTS - Investments (Details)
$ in Millions
 6 Months Ended 12 Months Ended
Jun. 30, 2025
USD ($)
borrower
Dec. 31, 2024
USD ($)
borrower
Schedule of Investments [Line Items]    
Amortized Cost $ 27,580.7 [1] $ 26,374.0 [2]
Fair Value $ 27,886.4 [1] $ 26,719.9 [2]
Loans on non-accrual status, as a percent of total investments at amortized cost 2.00% 1.70%
Loans on non-accrual status, as a percent of total investments at fair value 1.20% 1.00%
Investments, At Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 100.00% 100.00%
Investments, At Fair Value | Geographic Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 100.00% 100.00%
Senior Direct Lending Program    
Schedule of Investments [Line Items]    
Number of borrowers | borrower 19 20
Ivy Hill Asset Management, L.P.    
Schedule of Investments [Line Items]    
Amortized Cost $ 2,652.0 $ 2,237.0
Fair Value $ 9,841.0 $ 8,172.0
Number of borrowers | borrower 21  
West | Investments, At Fair Value | Geographic Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 22.30% 25.20%
West | Senior Direct Lending Program | Investments, At Fair Value | Customer Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 3.80% 4.50%
West | Ivy Hill Asset Management, L.P. | Investments, At Fair Value | Customer Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 7.40% 7.10%
Midwest | Investments, At Fair Value | Geographic Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 21.80% 20.90%
Southeast | Investments, At Fair Value | Geographic Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 18.20% 19.30%
Mid-Atlantic | Investments, At Fair Value | Geographic Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 16.60% 16.10%
Northeast | Investments, At Fair Value | Geographic Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 14.70% 12.20%
International | Investments, At Fair Value | Geographic Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 6.40% 6.30%
Software and Services    
Schedule of Investments [Line Items]    
Amortized Cost $ 6,557.1 $ 6,561.9
Fair Value $ 6,552.3 $ 6,544.6
Software and Services | Investments, At Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 23.50% 24.50%
Health Care Equipment and Services    
Schedule of Investments [Line Items]    
Amortized Cost $ 3,746.7 $ 3,333.6
Fair Value $ 3,604.7 $ 3,211.9
Health Care Equipment and Services | Investments, At Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 12.90% 12.00%
Financial Services    
Schedule of Investments [Line Items]    
Amortized Cost $ 2,575.2 $ 2,400.2
Fair Value $ 2,848.1 $ 2,644.8
Financial Services | Investments, At Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 10.20% 9.90%
Commercial and Professional Services    
Schedule of Investments [Line Items]    
Amortized Cost $ 2,792.9 $ 2,486.8
Fair Value $ 2,764.9 $ 2,510.0
Commercial and Professional Services | Investments, At Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 9.90% 9.40%
Insurance    
Schedule of Investments [Line Items]    
Amortized Cost $ 1,754.0 $ 1,510.1
Fair Value $ 1,788.5 $ 1,573.5
Insurance | Investments, At Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 6.40% 5.90%
Consumer Distribution and Retail | Investments, At Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 4.70% 5.70%
Consumer Services    
Schedule of Investments [Line Items]    
Amortized Cost $ 1,237.6 $ 1,284.0
Fair Value $ 1,283.3 $ 1,357.6
Consumer Services | Investments, At Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 4.60% 5.10%
Sports, Media and Entertainment    
Schedule of Investments [Line Items]    
Amortized Cost $ 1,246.6 $ 1,214.2
Fair Value $ 1,249.6 $ 1,218.3
Sports, Media and Entertainment | Investments, At Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 4.50% 4.60%
Investment Funds and Vehicles    
Schedule of Investments [Line Items]    
Amortized Cost $ 1,079.4 $ 1,288.2
Fair Value $ 1,075.9 $ 1,238.4
Investment Funds and Vehicles | Investments, At Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 3.80% 4.60%
Independent Power and Renewable Electricity Producers    
Schedule of Investments [Line Items]    
Amortized Cost $ 799.8  
Fair Value $ 1,068.4  
Independent Power and Renewable Electricity Producers | Investments, At Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 3.80% 3.70%
Capital Goods    
Schedule of Investments [Line Items]    
Amortized Cost $ 869.3 $ 710.9
Fair Value $ 880.8 $ 736.5
Capital Goods | Investments, At Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 3.20% 2.70%
Pharmaceuticals, Biotechnology and Life Sciences    
Schedule of Investments [Line Items]    
Amortized Cost $ 694.7 $ 705.8
Fair Value $ 689.9 $ 695.4
Pharmaceuticals, Biotechnology and Life Sciences | Investments, At Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 2.50% 2.60%
Materials    
Schedule of Investments [Line Items]    
Amortized Cost $ 629.4 $ 401.9
Fair Value $ 624.3 $ 317.1
Materials | Investments, At Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 2.20% 1.20%
Consumer Durables and Apparel    
Schedule of Investments [Line Items]    
Amortized Cost $ 639.2 $ 644.7
Fair Value $ 602.1 $ 606.4
Consumer Durables and Apparel | Investments, At Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 2.20% 2.30%
Food and Beverage    
Schedule of Investments [Line Items]    
Amortized Cost $ 523.4 $ 479.4
Fair Value $ 498.2 $ 479.6
Food and Beverage | Investments, At Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 1.80% 1.80%
Other | Investments, At Fair Value | Industry Concentration Risk    
Schedule of Investments [Line Items]    
Composition, percent of fair value 3.80% 4.00%
First lien senior secured loans    
Schedule of Investments [Line Items]    
Amortized Cost $ 16,827.0 $ 15,519.0
Fair Value 16,547.0 15,179.0
Second lien senior secured loans    
Schedule of Investments [Line Items]    
Amortized Cost 1,609.0 1,935.0
Fair Value 1,523.0 1,847.0
Subordinated certificates of the SDLP    
Schedule of Investments [Line Items]    
Amortized Cost 1,063.0 1,263.0
Fair Value 1,052.0 1,192.0
Senior subordinated loans    
Schedule of Investments [Line Items]    
Amortized Cost 1,456.0 1,384.0
Fair Value 1,388.0 1,351.0
Preferred equity    
Schedule of Investments [Line Items]    
Amortized Cost 2,753.0 2,667.0
Fair Value 2,642.0 2,649.0
Ivy Hill Asset Management, L.P.    
Schedule of Investments [Line Items]    
Amortized Cost 1,856.0 1,701.0
Fair Value 2,081.0 1,915.0
Other equity    
Schedule of Investments [Line Items]    
Amortized Cost 2,017.0 1,905.0
Fair Value 2,653.0 2,587.0
Unitranche loans    
Schedule of Investments [Line Items]    
Amortized Cost 10,650.0 8,772.0
Fair Value $ 10,489.0 $ 8,624.0
[1] As of June 30, 2025, the estimated net unrealized gain for federal tax purposes was approximately $0.3 billion based on a tax cost basis of $27.5 billion. As of June 30, 2025, the estimated aggregate gross unrealized gain for federal income tax purposes was approximately $1.8 billion and the estimated aggregate gross unrealized loss for federal income tax purposes was approximately $1.5 billion.
[2] As of December 31, 2024, the estimated net unrealized gain for federal tax purposes was $0.2 billion based on a tax cost basis of $26.5 billion. As of December 31, 2024, the estimated aggregate gross unrealized gain for federal income tax purposes was $1.7 billion and the estimated aggregate gross unrealized loss for federal income tax purposes was $1.5 billion.