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Fair Value Measurements - Fair Value Hierarchy of Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	$ 10,439,173	$ 9,868,440
First lien debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	10,287,119	9,722,061
Second lien debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	41,515	41,515
Unsecured debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	11,859	9,924
Investments in equity
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	98,680	94,940
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 | Unsecured 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 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	108,808	157,858
Level 2 | First lien debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	108,808	157,858
Level 2 | Second lien debt
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	0
Level 2 | Investments in equity
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	0	0
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	10,330,365	9,710,582
Level 3 | First lien debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	10,178,311	9,564,203
Level 3 | Second lien debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	41,515	41,515
Level 3 | Unsecured debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	11,859	9,924
Level 3 | Investments in equity
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	$ 98,680	$ 94,940

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- Definition

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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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