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Investment Funds (Details) - USD ($) $ in Thousands |  | 3 Months Ended | 6 Months Ended | 18 Months Ended |
--- | --- | --- | --- | --- | ---
Jul. 01, 2022 | Jun. 30, 2024 | Jun. 30, 2023 | Jun. 30, 2024 | Jun. 30, 2023 | Jun. 30, 2022 | Dec. 31, 2023
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Unfunded commitments |  | $ 275,000 |  | $ 275,000 |  |  |
Investment funds |  | 1,589,119 |  | 1,589,119 |  |  | $ 1,621,655
Income (Loss) from Investment Funds |  |  |  | (3,873) | $ 993 |  |
Written premiums ceded |  | 590,993 | $ 525,258 | 1,102,458 | 999,751 |  |
Fair Value |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Trading account receivables from brokers and clearing organizations |  | 40,705 |  | 40,705 |  |  | 303,614
Lifson Re |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Percentage of reinsurance placements of share placed amounts | 30.00% |  |  |  |  | 22.50% |
Written premiums ceded |  |  |  | 206,000 | 281,000 |  |
Financial services |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Investment funds |  | 198,111 |  | 198,111 |  |  | 201,625
Income (Loss) from Investment Funds |  |  |  | 12,880 | 2,963 |  |
Transportation |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Investment funds |  | 436,057 |  | 436,057 |  |  | 433,407
Income (Loss) from Investment Funds |  |  |  | (18,231) | (20,321) |  |
Real Estate |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Investment funds |  | 306,485 |  | 306,485 |  |  | 344,278
Income (Loss) from Investment Funds |  |  |  | (3,732) | 23,843 |  |
Energy |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Investment funds |  | 131,719 |  | 131,719 |  |  | 114,794
Income (Loss) from Investment Funds |  |  |  | 8,505 | 3,439 |  |
Infrastructure |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Investment funds |  | 140,699 |  | 140,699 |  |  | 130,589
Income (Loss) from Investment Funds |  |  |  | 7,828 | 5,936 |  |
Other funds |  |  |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |  |  |
Investment funds |  | 376,048 |  | 376,048 |  |  | 396,962
Income (Loss) from Investment Funds |  |  |  | (11,123) | $ (14,867) |  |
Deferred compensation trust assets |  | $ 41,000 |  | $ 41,000 |  |  | $ 36,000

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