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Fair Value Measurements - Fair Value Hierarchy of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	$ 9,868,440	$ 9,617,248
First lien debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	9,722,061	9,419,963
Second lien debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	41,515	46,336
Investments in equity
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	94,940	150,949
Unsecured debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	9,924
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	0	0
Level 1 | First lien debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	0	0
Level 1 | Second lien debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	0	0
Level 1 | Investments in equity
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	0	0
Level 1 | Unsecured debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	0
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	157,858	144,452
Level 2 | First lien debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	157,858	144,452
Level 2 | Second lien debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	0	0
Level 2 | Investments in equity
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	0	0
Level 2 | Unsecured debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	0
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	9,710,582	9,472,796
Level 3 | First lien debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	9,564,203	9,275,511
Level 3 | Second lien debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	41,515	46,336
Level 3 | Investments in equity
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	94,940	$ 150,949
Level 3 | Unsecured debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	$ 9,924

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+ References

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- Definition

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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