Investments - Schedule of Unamortized Capitalized Fee Income (Details) - USD ($) $ in Millions  | 
12 Months Ended | |
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Dec. 31, 2024  | 
Dec. 31, 2023  | 
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| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
| Total Unamortized Fee Income | $ 46.0 | $ 42.3 | 
| Offset against debt investment cost | ||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
| Total Unamortized Fee Income | 36.9 | 32.9 | 
| Deferred obligation contingent on funding or other milestone | ||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
| Total Unamortized Fee Income | $ 9.1 | $ 9.4 | 
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- Definition Unamortized Fee Income No definition available. 
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
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