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Investment Portfolio - Investment Portfolio, at Fair Value and Percentage (Details) - USD ($)
$ in Millions

12 Months Ended

Dec. 31, 2025

Dec. 31, 2024

Investment Company, Nonconsolidated Subsidiary [Line Items]

Investments, at fair value

$ 13,008.6

^[1]

$ 13,490.4

^[2]

Percentage of Portfolio | Industry Concentration Risk

Investment Company, Nonconsolidated Subsidiary [Line Items]

Percentage of Portfolio

100.00%

100.00%

Automobiles & Components

Investment Company, Nonconsolidated Subsidiary [Line Items]

Investments, at fair value

$ 0.0

$ 4.0

Automobiles & Components | Percentage of Portfolio | Industry Concentration Risk

Investment Company, Nonconsolidated Subsidiary [Line Items]

Percentage of Portfolio

0.00%

0.00%

Banks

Investment Company, Nonconsolidated Subsidiary [Line Items]

Investments, at fair value

$ 0.0

$ 5.0

Banks | Percentage of Portfolio | Industry Concentration Risk

Investment Company, Nonconsolidated Subsidiary [Line Items]

Percentage of Portfolio

0.00%

0.00%

Capital Goods

Investment Company, Nonconsolidated Subsidiary [Line Items]

Investments, at fair value

$ 1,542.0

$ 1,712.0

Capital Goods | Percentage of Portfolio | Industry Concentration Risk

Investment Company, Nonconsolidated Subsidiary [Line Items]

Percentage of Portfolio

11.90%

12.70%

Commercial & Professional Services

Investment Company, Nonconsolidated Subsidiary [Line Items]

Investments, at fair value

$ 1,726.0

$ 1,733.0

Commercial & Professional Services | Percentage of Portfolio | Industry Concentration Risk

Investment Company, Nonconsolidated Subsidiary [Line Items]

Percentage of Portfolio

13.30%

12.80%

Consumer Discretionary Distribution & Retail

Investment Company, Nonconsolidated Subsidiary [Line Items]

Investments, at fair value

$ 60.0

$ 174.0

Consumer Discretionary Distribution & Retail | Percentage of Portfolio | Industry Concentration Risk

Investment Company, Nonconsolidated Subsidiary [Line Items]

Percentage of Portfolio

0.50%

1.30%

Consumer Durables & Apparel

Investment Company, Nonconsolidated Subsidiary [Line Items]

Investments, at fair value

$ 306.0

$ 229.0

Consumer Durables & Apparel | Percentage of Portfolio | Industry Concentration Risk

Investment Company, Nonconsolidated Subsidiary [Line Items]

Percentage of Portfolio

2.40%

1.70%

Consumer Services

Investment Company, Nonconsolidated Subsidiary [Line Items]

Investments, at fair value

$ 263.0

$ 244.0

Consumer Services | Percentage of Portfolio | Industry Concentration Risk

Investment Company, Nonconsolidated Subsidiary [Line Items]

Percentage of Portfolio

2.00%

1.80%

Consumer Staples Distribution & Retail

Investment Company, Nonconsolidated Subsidiary [Line Items]

Investments, at fair value

$ 99.0

$ 102.0

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]

Investments, at fair value

$ 1,968.0

$ 1,363.0

Credit Opportunities Partners JV, LLC | Percentage of Portfolio | Industry Concentration Risk

Investment Company, Nonconsolidated Subsidiary [Line Items]

Percentage of Portfolio

15.10%

10.10%

Energy

Investment Company, Nonconsolidated Subsidiary [Line Items]

Investments, at fair value

$ 24.0

$ 89.0

Energy | Percentage of Portfolio | Industry Concentration Risk

Investment Company, Nonconsolidated Subsidiary [Line Items]

Percentage of Portfolio

0.20%

0.70%

Equity Real Estate Investment Trusts (REITs)

Investment Company, Nonconsolidated Subsidiary [Line Items]

Investments, at fair value

$ 264.0

$ 278.0

Equity Real Estate Investment Trusts (REITs) | Percentage of Portfolio | Industry Concentration Risk

Investment Company, Nonconsolidated Subsidiary [Line Items]

Percentage of Portfolio

2.00%

2.10%

Financial Services

Investment Company, Nonconsolidated Subsidiary [Line Items]

Investments, at fair value

$ 836.0

$ 998.0

Financial Services | Percentage of Portfolio | Industry Concentration Risk

Investment Company, Nonconsolidated Subsidiary [Line Items]

Percentage of Portfolio

6.40%

7.40%

Food, Beverage & Tobacco

Investment Company, Nonconsolidated Subsidiary [Line Items]

Investments, at fair value

$ 56.0

$ 113.0

Food, Beverage & Tobacco | Percentage of Portfolio | Industry Concentration Risk

Investment Company, Nonconsolidated Subsidiary [Line Items]

Percentage of Portfolio

0.40%

0.80%

Health Care Equipment & Services

Investment Company, Nonconsolidated Subsidiary [Line Items]

Investments, at fair value

$ 1,668.0

$ 1,667.0

Health Care Equipment & Services | Percentage of Portfolio | Industry Concentration Risk

Investment Company, Nonconsolidated Subsidiary [Line Items]

Percentage of Portfolio

12.80%

12.40%

Household & Personal Products

Investment Company, Nonconsolidated Subsidiary [Line Items]

Investments, at fair value

$ 112.0

$ 134.0

Household & Personal Products | Percentage of Portfolio | Industry Concentration Risk

Investment Company, Nonconsolidated Subsidiary [Line Items]

Percentage of Portfolio

0.90%

1.00%

Insurance

Investment Company, Nonconsolidated Subsidiary [Line Items]

Investments, at fair value

$ 547.0

$ 735.0

Insurance | Percentage of Portfolio | Industry Concentration Risk

Investment Company, Nonconsolidated Subsidiary [Line Items]

Percentage of Portfolio

4.20%

5.40%

Materials

Investment Company, Nonconsolidated Subsidiary [Line Items]

Investments, at fair value

$ 276.0

$ 334.0

Materials | Percentage of Portfolio | Industry Concentration Risk

Investment Company, Nonconsolidated Subsidiary [Line Items]

Percentage of Portfolio

2.10%

2.50%

Media & Entertainment

Investment Company, Nonconsolidated Subsidiary [Line Items]

Investments, at fair value

$ 508.0

$ 699.0

Media & Entertainment | Percentage of Portfolio | Industry Concentration Risk

Investment Company, Nonconsolidated Subsidiary [Line Items]

Percentage of Portfolio

3.90%

5.20%

Pharmaceuticals, Biotechnology & Life Sciences

Investment Company, Nonconsolidated Subsidiary [Line Items]

Investments, at fair value

$ 217.0

$ 298.0

Pharmaceuticals, Biotechnology & Life Sciences | Percentage of Portfolio | Industry Concentration Risk

Investment Company, Nonconsolidated Subsidiary [Line Items]

Percentage of Portfolio

1.70%

2.20%

Real Estate Management & Development

Investment Company, Nonconsolidated Subsidiary [Line Items]

Investments, at fair value

$ 1.0

$ 27.0

Real Estate Management & Development | Percentage of Portfolio | Industry Concentration Risk

Investment Company, Nonconsolidated Subsidiary [Line Items]

Percentage of Portfolio

0.00%

0.20%

Software & Services

Investment Company, Nonconsolidated Subsidiary [Line Items]

Investments, at fair value

$ 2,134.0

$ 2,187.0

Software & Services | Percentage of Portfolio | Industry Concentration Risk

Investment Company, Nonconsolidated Subsidiary [Line Items]

Percentage of Portfolio

16.40%

16.20%

Technology Hardware & Equipment

Investment Company, Nonconsolidated Subsidiary [Line Items]

Investments, at 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]

Investments, at fair value

$ 109.0

$ 69.0

Telecommunication Services | Percentage of Portfolio | Industry Concentration Risk

Investment Company, Nonconsolidated Subsidiary [Line Items]

Percentage of Portfolio

0.80%

0.50%

Transportation

Investment Company, Nonconsolidated Subsidiary [Line Items]

Investments, at fair value

$ 291.0

$ 294.0

Transportation | Percentage of Portfolio | Industry Concentration Risk

Investment Company, Nonconsolidated Subsidiary [Line Items]

Percentage of Portfolio

2.20%

2.20%

[1]	See Note 8 for additional information regarding the fair value of the Company’s financial instruments.
[2]	See Note 8 for additional information regarding the fair value of the Company’s financial instruments.

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